Within the extended vector meson dominance model,we investigate the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction and the electromagnetic form factors of the charmed baryon𝛬 Λ_(c)^(+)𝑐.The model par...Within the extended vector meson dominance model,we investigate the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction and the electromagnetic form factors of the charmed baryon𝛬 Λ_(c)^(+)𝑐.The model parameters are determined by fitting them to the cross sections of the process𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) and the magnetic form factor|G_(M)|of Λ_(c)^(+) .By considering four charmonium-like states,called𝜓(4500),𝜓(4660),𝜓(4790),and𝜓(4900),we can well describe the current data on the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction from the reaction threshold up to 4.96 GeV.In addition to the total cross sections and|𝐺M|,the ratio|G_(E)/G_(M)|and the effective form factor|Geff|for Λ_(c)^(+) 𝑐are also calculated,and found that these calculations are consistent with the experimental data.Within the fitted model parameters,we have also estimated the charge radius of the charmed Λ_(c)^(+) baryon.展开更多
The electrocatalytic water splitting technology can generate highpurity hydrogen without emitting carbon dioxide,which is in favor of relieving environmental pollution and energy crisis and achieving carbon neutrality...The electrocatalytic water splitting technology can generate highpurity hydrogen without emitting carbon dioxide,which is in favor of relieving environmental pollution and energy crisis and achieving carbon neutrality.Electrocatalysts can effectively reduce the reaction energy barrier and increase the reaction efficiency.Facet engineering is considered as a promising strategy in controlling the ratio of desired crystal planes on the surface.Owing to the anisotropy,crystal planes with different orientations usually feature facet-dependent physical and chemical properties,leading to differences in the adsorption energies of oxygen or hydrogen intermediates,and thus exhibit varied electrocatalytic activity toward hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).In this review,a brief introduction of the basic concepts,fundamental understanding of the reaction mechanisms as well as key evaluating parameters for both HER and OER are provided.The formation mechanisms of the crystal facets are comprehensively overviewed aiming to give scientific theory guides to realize dominant crystal planes.Subsequently,three strategies of selective capping agent,selective etching agent,and coordination modulation to tune crystal planes are comprehensively summarized.Then,we present an overview of significant contributions of facet-engineered catalysts toward HER,OER,and overall water splitting.In particular,we highlight that density functional theory calculations play an indispensable role in unveiling the structure–activity correlation between the crystal plane and catalytic activity.Finally,the remaining challenges in facet-engineered catalysts for HER and OER are provided and future prospects for designing advanced facet-engineered electrocatalysts are discussed.展开更多
A study of a nanosecond laser irradiation on the titanium-layer-buried gold planar target is presented. The timeresolved x-ray emission spectra of titanium tracer are measured by a streaked crystal spectrometer. By co...A study of a nanosecond laser irradiation on the titanium-layer-buried gold planar target is presented. The timeresolved x-ray emission spectra of titanium tracer are measured by a streaked crystal spectrometer. By comparing the simulated spectra obtained by using the FLYCHK code with the measured titanium spectra, the temporal plasma states, i.e.,the electron temperatures and densities, are deduced. To evaluate the feasibility of using the method for the characterization of Au plasma states, the deduced plasma states from the measured titanium spectra are compared with the Multi-1D hydrodynamic simulations of laser-produced Au plasmas. By comparing the measured and simulated results, an overall agreement for the electron temperatures is found, whereas there are deviations in the electron densities. The experiment–theory discrepancy may suggest that the plasma state could not be well reproduced by the Multi-1D hydrodynamic simulation, in which the radial gradient is not taken into account. Further investigations on the spectral characterization and hydrodynamic simulations of the plasma states are needed. All the measured and FLYCHK simulated spectra are given in this paper as datasets. The datasets are openly available at http://www.doi.org/10.57760/sciencedb.j00113.00032.展开更多
AIM: To determine the underlying mechanisms of action and influence of Xiaotan Sanjie(XTSJ) decoction on gastric cancer stem-like cells(GCSCs). METHODS: The gastric cancer cell line MKN-45 line was selected and sorted...AIM: To determine the underlying mechanisms of action and influence of Xiaotan Sanjie(XTSJ) decoction on gastric cancer stem-like cells(GCSCs). METHODS: The gastric cancer cell line MKN-45 line was selected and sorted by FACS using the cancer stem cell marker CD44; the stemness of these cells was checked in our previous study. In an in vitro study, the expression of Notch-1, Hes1, Vascular endothelial growth factor(VEGF), and Ki-67 in both CD44-positive gastric cancer stem-like cells(GCSCs) and CD44-negative cells was measured by Western blot. The effect of XTSJ serum on cell viability and on the above markers was measured by MTT assay and Western blot, respectively. In an in vivo study, the ability to induce angiogenesis and maintenance of GCSCs in CD44-positive-MKN-45- and CD44-negative-engrafted mice were detected by immunohistochemical staining using markers for CD34 and CD44, respectively. The role of XTSJ decoction in regulating the expression of Notch-1, Hes1, VEGF and Ki-67 was measured by Western blot and real-time polymerase chain reaction.RESULTS: CD44+ GCSCs showed more cell proliferation and VEGF secretion than CD44-negative cells in vitro, which were accompanied by the high expression of Notch-1 and Hes1 and positively associated with tumor growth(GCSCs vs CD44-negative cells, 2.72 ± 0.25 vs 1.46 ± 0.16, P < 0.05) and microvessel density(MVD)(GCSCs vs CD44-negative cells, 8.15 ± 0.42 vs 3.83 ± 0.49, P < 0.001) in vivo. XTSJ decoction inhibited the viability of both cell types in a dose-dependent manner in vitro. Specifically, a significant difference in the medium-(82.87% ± 6.53%) and high-dose XTSJ groups(77.43% ± 7.34%) was detected at 24 h in the CD44+ GCSCs group compared with the saline group(95.42% ± 5.76%) and the low-dose XTSJ group(90.74% ± 6.57%)(P < 0.05). However, the efficacy of XTSJ decoction was reduced in the CD44- groups; significant differences were only detected in the high-dose XTSJ group at 48 h(78.57% ± 6.94%) and 72 h(72.12% ± 7.68%) when compared with the other CD44- groups(P < 0.05). Notably, these differences were highly consistent with the Notch-1, Hes1, VEGF and Ki-67 expression in these cells. Similarly, in vivo, XTSJ decoction inhibited tumor growth in a dose-dependent manner. A significant difference was observed in the medium(1.76 ± 0.15) and high-dose XTSJ(1.33 ± 0.081) groups compared with the GCSCs control group(2.72 ± 0.25) and the low-dose XTSJ group(2.51 ± 0.25)(P < 0.05). We also detected a remarkable decrease of MVD in the medium-(7.10 ± 0.60) and high-dose XTSJ(5.99 ± 0.47) groups compared with the GCSC control group(8.15 ± 0.42) and the low-dose XTSJ group(8.14 ± 0.46)(P < 0.05). Additionally, CD44 expression was decreased in these groups [medium-(4.43 ± 0.45) and high-dose XTSJ groups(3.56 ± 0.31) vs the GCSC control(5.96 ± 0.46) and low dose XTSJ groups(5.91 ± 0.38)](P < 0.05). The significant differences in Notch-1, Hes1, VEGF and Ki-67 expression highly mirrored the results of XTSJ decoction in inhibiting tumor growth, MVD and CD44 expression.CONCLUSION: Notch-1 may play an important role in regulating the proliferation of GCSCs; XTSJ decoction could attenuate tumor angiogenesis, at least partially, by inhibiting Notch-1.展开更多
AIM:To investigate the efficacy and potential mechanism of Xiaotan Tongfu granules(XTTF)in stress ulcers.METHODS:One hundred sixty rats were randomly divided into 4 groups(n=10)as follows:the model group(MP group),the...AIM:To investigate the efficacy and potential mechanism of Xiaotan Tongfu granules(XTTF)in stress ulcers.METHODS:One hundred sixty rats were randomly divided into 4 groups(n=10)as follows:the model group(MP group),the control group(CP group),the ranitidine group(RP group)and the XTTF granule group(XP group).Rats in the MP group received no drugs,rats in the CP group received 0.2 mL of a 0.9%sodium chloride solution via oral gavage,and rats in the RP and XP groups received the same volume of ranitidine(50 mg/kg)or XTTF granule(4.9 g/kg).The cold-restraint stress model was applied to induce stress ulcers after 7 consecutive days of drug administration.Afterwards,rats were sacrificed at 0,3,6 and24 h.Gastric pH was measured by a precise pH meter;gastric emptying rate(GER)was measured by using a methylcellulose test meal;myeloperoxidase activity(MPO),macrophage migration inhibitory factor(MIF),proliferating cell nuclear antigen(PCNA),and heat shock protein 70(HSP70)were measured by immunohistochemical staining;and mucosal cell apoptosis was measured by transferase dUTP nick end labeling.RESULTS:In the cold-restraint stress model,the development of stress ulcers peaked at 3 h and basically regressed after 24 h.Gastric lesions were significantly different in the RP and XP groups at each time point.Interestingly,although this index was much lower in the RP group than in the XP group immediately following stress induction(7.00±1.10 vs 10.00±1.79,P<0.05.Concerning gastric pH,between the RP and XP groups,we detected a statistically significant difference immediately after stress induction(0 h:4.56±0.47 vs 3.34±0.28,P<0.05)but not at any of the subsequent time points.For GER,compared to the RP group,GER was remarkably elevated in the XP group because a statistically significant difference was detected(3 h:46.84±2.70 vs 61.16±5.12,P<0.05;6 h:60.96±6.71 vs 73.41±6.16,P<0.05;24 h:77.47±3.17 vs 91.31±4.34,P<0.05).With respect to MPO and MIF,comparisons between the RP and XP groups revealed statistically significant differences at 3 h(MPO:18.94±1.20 vs 13.51±0.89,P<0.05;MIF:150.67±9.85 vs 122.17±5.67,P<0.05)and 6 h(MPO:13.22±1.54 vs 8.83±0.65,P<0.05;MIF:135.50±9.46 vs 109.83±6.40,P<0.05).With regard to HSP70,HSP70 expression was significantly increased in the RP and XP groups at 3 and 6 h compared to the MP and CP groups.In addition,comparing the RP and XP groups also showed statistically significant differences at 3 and 6 h.The expression of PCNA was higher in the RP and XP groups 3 h after stress induction.Between these two groups,small but statistically significant differences were observed at all of the time points(3 h:69.50±21.52 vs 79.33±15.68,P<0.05;6 h:107.83±4.40 vs 121.33±5.71,P<0.05;24 h:125.33±5.65 vs 128.50±14.49,P<0.05)except 0 h.With regard to apoptosis,the apoptotic activity in the RP and XP groups was significantly different from that in the MP and CP groups.The XP group exhibited a higher inhibition of cell apoptosis than the RP group at3 h(232.58±24.51 vs 174.46±10.35,P<0.05)and6 h(164.74±18.31 vs 117.71±12.08,P<0.05).CONCLUSION:The Xiaotan Tongfu granule was demonstrated to be similar to ranitidine in preventing stress ulcers.It exhibited multiple underlying mechanisms and deserves further study.展开更多
Boron-based metal-free catalysts for oxidative dehydrogenation of propane(ODHP)have drawn great attention in both academia and industry due to their impressive activity and olefin selectivity.Herein,the SiO2 and B2O3 ...Boron-based metal-free catalysts for oxidative dehydrogenation of propane(ODHP)have drawn great attention in both academia and industry due to their impressive activity and olefin selectivity.Herein,the SiO2 and B2O3 sequentially coated honeycomb cordierite catalyst is designed by a two-step wash-coat method with different B2O3 loadings(0.1%–10%)and calcination temperatures(600,700,800℃).SiO2 obtained by TEOS hydrolysis acts as a media layer to bridge the cordierite substrate and boron oxide via abundant Si\\OH groups.The welldeveloped straight channels of honeycomb cordierite make it possible to carry out the reactor under high gas hourly space velocity(GHSV)and the thin wash-coated B2O3 layer can effectively facilitate the pore diffusion on the catalyst.The prepared B2O3/SiO2@HC monolithic catalyst exhibits good catalytic performance at low boron oxide loading and achieves excellent propylene selectivity(86.0%),olefin selectivity(97.6%,propylene and ethylene)and negligible CO2(0.1%)at 16.9%propane conversion under high GHSV of 345,600 ml·(g B2O3)^-1·h^-1,leading to a high propylene space time yield of 15.7 g C3H6·(g B2O3)^-1·h^-1 by suppressing the overoxidation.The obtained results strongly indicate that the boron-based monolithic catalyst can be properly fabricated to warrant the high activity and high throughput with its high gas/surface ratio and straight channels.展开更多
Summary:The COVID-19 pandemic caused by SARS-CoV2 is characterized by a remarkable variation in clinical severity ranging from a mild illness to a fatal multi-organ disease.Understanding the dysregulated human immune ...Summary:The COVID-19 pandemic caused by SARS-CoV2 is characterized by a remarkable variation in clinical severity ranging from a mild illness to a fatal multi-organ disease.Understanding the dysregulated human immune responses in the fatal subjects is critical for management of COVID-19 patients and the pandemic.In this study,we examined the immune cell compositions in the lung tissues and hilar lymph nodes using immunohistochemistry on 6 deceased COVID-19 patients and 4 focal organizing pneumonia(FOP)patients who underwent lung surgery and served as controls.We found a dominant presence of macrophages and a general deficiency of T cells and B cells in the lung tissues from deceased COVID-19 patients.In contrast to the FOP patients,Tfh cells and germinal center formation were largely absent in the draining hilar lymph nodes in the deceased COVID-19 patients.This was correlated with reduced IgM and IgG levels compared to convalescent COVID-19 patients.In summary,our data highlight a defect of germinal center structure in deceased COVID-19 patients leading to an impaired humoral immunity.Understanding the mechanisms of this deficiency will be one of the key points for the management of this epidemic.展开更多
Therapy-related acute myeloid leukemia(t-AML) refers to a heterogeneous group of myeloid neoplasms that develop in patients following extensive exposure to either cytotoxic agents or radiation.The development of t-AML...Therapy-related acute myeloid leukemia(t-AML) refers to a heterogeneous group of myeloid neoplasms that develop in patients following extensive exposure to either cytotoxic agents or radiation.The development of t-AML has been reported following treatment of cancers ranging from hematological malignancies to solid tumors; however, to our knowledge, t-AML has never been reported following treatment of gastric cancer.In this study, we report the development of t-acute promyelocytic leukemia in a cT 4N1M0 gastric cancer patient after an approximate 44 mo latency period following treatment with 4 cycles of oxaliplatin(OXP)(85 mg/m2 on day 1) plus capecitabine(1250 mg/m2 orally twice daily on days 1-14) in combination with recombinant human granulocyte-colony stimulating factor treatment.Karyotype analysis of the patient revealed 46,XY,t(15;17)(q22;q21)[15]/46,idem,-9,+add(9)(p22)[2]/46,XY[3], which, according to previous studies, includes some "favorable" genetic abnormalities.The patient was then treated with all-trans retinoic acid(ATRA, 25 mg/m2/d) plus arsenic trioxide(ATO, 10 mg/d) and attained complete remission.Our case illuminated the role of certain cytotoxic agents in the induction of t-AML following gastric cancer treatment.We recommend instituting a mandatory additional evaluation for patients undergoing these therapies in the future.展开更多
The accurate equilibrium structures of S_3 and S_3^- are determined by the coupled-cluster method with single, double excitation and perturbative triple excitation(CCSD(T)) with basis sets of aug-cc-pV(n+d)Z(n = T, Q,...The accurate equilibrium structures of S_3 and S_3^- are determined by the coupled-cluster method with single, double excitation and perturbative triple excitation(CCSD(T)) with basis sets of aug-cc-pV(n+d)Z(n = T, Q, 5, or 6), complete basis set extrapolation functions with two-parameters and three-parameters, together with considering the contributions due to the core-valence electron correlation, scalar relativistic effects, spin–orbit coupling, and zero-point vibrational corrections. Our calculations show that both the neutral S_3 and anion S_3^- have open forms with C_(2r) vsymmetry. On the basis of the stable geometries, the adiabatic electron affinity of S_3 is determined to be 19041(11) cm^(-1), which is in excellent agreement with the experimental data(19059(7) cm^(-1)). The dependence of geometries and electron affinity on the computation level and physical corrections is discussed. The present computational results are helpful to the experimental molecular spectroscopy and bonding of S_3.展开更多
A field-modulated electroosmotic flow （FMEOF） in a microchannel can be obtained by applying modulating electric fields in a direction perpendicular to the channel wall. Micro-vortexes are generated around the electr...A field-modulated electroosmotic flow （FMEOF） in a microchannel can be obtained by applying modulating electric fields in a direction perpendicular to the channel wall. Micro-vortexes are generated around the electrodes along with an EOF due to the surface charge on the modulated wall. When polarizable particles are suspended near the electrodes, they experience dielectrophoretic forces due to a non-uniform electric field. In this paper, micro-vortexes and dielectrophoretic forces are combined to achieve separation and trap different sized particles in a continuous flow. Numerical results indicate that by adjusting the driving electric field parallel to the channel wall and the modulating electric field, the ratio of dielectrophoretic and hydrodynamic forces can be altered. One type of particles can be trapped by micro-vortexes （negative dielectrophoresis （DEP））, and the other particles are transported to the downstream so that the particles are separated. The influence of the electrode length and the channel height on the trapping rate is investigated.展开更多
High-level ab initio calculations of aluminum monoiodide(AlI) molecule are performed by utilizing the multireference configuration interaction plus Davidson correction(MRCI+Q) method. The core-valence correlation(CV) ...High-level ab initio calculations of aluminum monoiodide(AlI) molecule are performed by utilizing the multireference configuration interaction plus Davidson correction(MRCI+Q) method. The core-valence correlation(CV) and spin–orbit coupling(SOC) effect are considered. The adiabatic potential energy curves(PECs) of a total of 13 Λ–S states and 24 ? states are computed. The spectroscopic constants of bound states are determined, which are in accordance with the results of the available experimental and theoretical studies. The interactions between the Λ–S states are analyzed with the aid of the spin–orbit matrix elements. Finally, the transition properties including transition dipole moment(TDM),Frank–Condon factors(FCF) and radiative lifetime are obtained based on the computed PEC. Our study sheds light on the electronic structure and spectroscopy of low-lying electronic states of the AlI molecule.展开更多
The potential energy curves, spectroscopic constants, and low-lying vibration–rotation levels of ground-state O2 and its cation O2+ and anion O2- were calculated with the explicitly correlated multireference configur...The potential energy curves, spectroscopic constants, and low-lying vibration–rotation levels of ground-state O2 and its cation O2+ and anion O2- were calculated with the explicitly correlated multireference configuration interaction method.The zeroth-order reference wavefunction was treated with the complete active space multiconfigurational self-consistent field method, in which the active space was carefully selected, and an additional molecular orbital πu was added into the full valence active space.The electron correlation of the 1s core in the oxygen atom was considered in the computations.The Davidson correction on molecular energy was considered to account for higher electron excitation.The relativistic effects, including the scalar relativistic effect and spin–orbit coupling, were considered in the computation of potential energy curves.These physical effects on the spectroscopic constants were examined.The low-lying levels of vibration–rotation spectra of O2 and its ions were determined based on the computed potential energy curves.Comparisons with available experiments were made and excellent agreement was obtained for the vibrational and rotational parameters.The spectroscopic constants and vibration–rotation spectrum of O2-, which is sparse in experiments, were provided.Our study will shed some light on further theoretical and experimental studies on these simple but important molecular systems.展开更多
Grid integration of wind power is essential to reduce fossil fuel usage but challenging in view of the intermittent nature of wind.Recently,we developed a hybrid Markovian and interval approach for the unit commitment...Grid integration of wind power is essential to reduce fossil fuel usage but challenging in view of the intermittent nature of wind.Recently,we developed a hybrid Markovian and interval approach for the unit commitment and economic dispatch problem where power generation of conventional units is linked to local wind states to dampen the effects of wind uncertainties.Also,to reduce complexity,extreme and expected states are considered as interval modeling.Although this approach is effective,the fact that major wind farms are often located in remote locations and not accompanied by conventional units leads to conservative results.Furthermore,weights of extreme and expected states in the objective function are difficult to tune,resulting in significant differences between optimization and simulation costs.In this paper,each remote wind farm is paired with a conventional unit to dampen the effects of wind uncertainties without using expensive utility-scaled battery storage,and extra constraints are innovatively established to model pairing.Additionally,proper weights are derived through a novel quadratic fit of cost functions.The problem is solved by using a creative integration of our recent surrogate Lagrangian relaxation and branch-and-cut.Results demonstrate modeling accuracy,computational efficiency,and significant reduction of conservativeness of the previous approach.展开更多
Dielectrophoresis(DEP)technology has become important application of microfluidic technology to manipulate particles.By using a local modulating electric field to control the combination of electroosmotic microvortice...Dielectrophoresis(DEP)technology has become important application of microfluidic technology to manipulate particles.By using a local modulating electric field to control the combination of electroosmotic microvortices and DEP,our group proposed a device using a direct current(DC)electric field to achieve continuous particle separation.In this paper,the influence of the Joule heating effect on the continuous separation of particles is analyzed.Results show that the Joule heating effect is caused by the local electric field,and the Joule heating effect caused by adjusting the modulating voltage is more significant than that by driving voltage.Moreover,a non-uniform temperature distribution exists in the channel due to the Joule heating effect,and the temperature is the highest at the midpoint of the modulating electrodes.The channel flux can be enhanced,and the enhancement of both the channel flux and temperature is more obvious for a stronger Joule heating effect.In addition,the ability of the vortices to trap particles is enhanced since a larger DEP force is exerted on the particles with the Joule heating effect;and the ability of the vortex to capture particles is stronger with a stronger Joule heating effect.The separation efficiency can also be increased because perfect separation is achieved at a higher channel flux.Parameter optimization of the separation device,such as the convective heat transfer coefficient of the channel wall,the length of modulating electrode,and the width of the channel,is performed.展开更多
The dielectrophoretic technology has been one of the most frequently applied microfluidic technologies to manipulate particles.The way of a combination of controlled electroosmotic micro-vortices and dielectrophoresis...The dielectrophoretic technology has been one of the most frequently applied microfluidic technologies to manipulate particles.The way of a combination of controlled electroosmotic micro-vortices and dielectrophoresis to manipulate particles of different sizes was proposed in our previous work.However,the thickness of the modulating electrode is neglected.In practice,when the thickness of the modulating electrode increases,the channel flux increases,while the ability of the vortex to capture the particles reduces.In this study,a new method combining the field-modulating electroosmotic vortex and the insulating post is proposed to improve the manipulating capability of the field-modulated electroosmotic vortex to particles.The results indicate that there are three great advantages as the insulating post is placed on the channel wall on the same side of the modulating electrode.First,the capturing ability of the vortex to particles is greater due to the reduction of channel flux and the squeezing effect.Second,the range of regulating channel flux to achieve the optimal separation is extended.Third,the separation efficiency improves since the perfect separation can be achieved at a higher flow rate.Furthermore,the effects of the location and the size of the insulating post on particle separation are analyzed in detail.The present work could provide the reference for the application of the DEP technology.展开更多
基金supported by the National Key R&D Program of China(Grant No.2023YFA1606703)the National Natural Science Foundation of China(Grant No.12075288)the Youth Innovation Promotion Association CAS.
文摘Within the extended vector meson dominance model,we investigate the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction and the electromagnetic form factors of the charmed baryon𝛬 Λ_(c)^(+)𝑐.The model parameters are determined by fitting them to the cross sections of the process𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) and the magnetic form factor|G_(M)|of Λ_(c)^(+) .By considering four charmonium-like states,called𝜓(4500),𝜓(4660),𝜓(4790),and𝜓(4900),we can well describe the current data on the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction from the reaction threshold up to 4.96 GeV.In addition to the total cross sections and|𝐺M|,the ratio|G_(E)/G_(M)|and the effective form factor|Geff|for Λ_(c)^(+) 𝑐are also calculated,and found that these calculations are consistent with the experimental data.Within the fitted model parameters,we have also estimated the charge radius of the charmed Λ_(c)^(+) baryon.
基金support from the National Natural Science Foundation of China(No.22005147)Dr.You acknowledges the financial support from the National Key Research and Development Program of China(2021YFA1600800)+1 种基金the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003)the Open Research Fund of Key Laboratory of Material Chemistry for Energy Conversion and Storage(HUST),Ministry of Education(2021JYBKF03).
文摘The electrocatalytic water splitting technology can generate highpurity hydrogen without emitting carbon dioxide,which is in favor of relieving environmental pollution and energy crisis and achieving carbon neutrality.Electrocatalysts can effectively reduce the reaction energy barrier and increase the reaction efficiency.Facet engineering is considered as a promising strategy in controlling the ratio of desired crystal planes on the surface.Owing to the anisotropy,crystal planes with different orientations usually feature facet-dependent physical and chemical properties,leading to differences in the adsorption energies of oxygen or hydrogen intermediates,and thus exhibit varied electrocatalytic activity toward hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).In this review,a brief introduction of the basic concepts,fundamental understanding of the reaction mechanisms as well as key evaluating parameters for both HER and OER are provided.The formation mechanisms of the crystal facets are comprehensively overviewed aiming to give scientific theory guides to realize dominant crystal planes.Subsequently,three strategies of selective capping agent,selective etching agent,and coordination modulation to tune crystal planes are comprehensively summarized.Then,we present an overview of significant contributions of facet-engineered catalysts toward HER,OER,and overall water splitting.In particular,we highlight that density functional theory calculations play an indispensable role in unveiling the structure–activity correlation between the crystal plane and catalytic activity.Finally,the remaining challenges in facet-engineered catalysts for HER and OER are provided and future prospects for designing advanced facet-engineered electrocatalysts are discussed.
基金Project supported by the National Key Research and Development Program of China (Grant No.2017YFA0403300)the National Natural Science Foundation of China (Grant Nos.12074352 and 11675158)Fundamental Research Funds for the Central Universities in China (Grant No.YJ202144)。
文摘A study of a nanosecond laser irradiation on the titanium-layer-buried gold planar target is presented. The timeresolved x-ray emission spectra of titanium tracer are measured by a streaked crystal spectrometer. By comparing the simulated spectra obtained by using the FLYCHK code with the measured titanium spectra, the temporal plasma states, i.e.,the electron temperatures and densities, are deduced. To evaluate the feasibility of using the method for the characterization of Au plasma states, the deduced plasma states from the measured titanium spectra are compared with the Multi-1D hydrodynamic simulations of laser-produced Au plasmas. By comparing the measured and simulated results, an overall agreement for the electron temperatures is found, whereas there are deviations in the electron densities. The experiment–theory discrepancy may suggest that the plasma state could not be well reproduced by the Multi-1D hydrodynamic simulation, in which the radial gradient is not taken into account. Further investigations on the spectral characterization and hydrodynamic simulations of the plasma states are needed. All the measured and FLYCHK simulated spectra are given in this paper as datasets. The datasets are openly available at http://www.doi.org/10.57760/sciencedb.j00113.00032.
基金Supported by Project of Experimental Animal Research(the Science and Technology Commission of Shanghai),No.13140901803
文摘AIM: To determine the underlying mechanisms of action and influence of Xiaotan Sanjie(XTSJ) decoction on gastric cancer stem-like cells(GCSCs). METHODS: The gastric cancer cell line MKN-45 line was selected and sorted by FACS using the cancer stem cell marker CD44; the stemness of these cells was checked in our previous study. In an in vitro study, the expression of Notch-1, Hes1, Vascular endothelial growth factor(VEGF), and Ki-67 in both CD44-positive gastric cancer stem-like cells(GCSCs) and CD44-negative cells was measured by Western blot. The effect of XTSJ serum on cell viability and on the above markers was measured by MTT assay and Western blot, respectively. In an in vivo study, the ability to induce angiogenesis and maintenance of GCSCs in CD44-positive-MKN-45- and CD44-negative-engrafted mice were detected by immunohistochemical staining using markers for CD34 and CD44, respectively. The role of XTSJ decoction in regulating the expression of Notch-1, Hes1, VEGF and Ki-67 was measured by Western blot and real-time polymerase chain reaction.RESULTS: CD44+ GCSCs showed more cell proliferation and VEGF secretion than CD44-negative cells in vitro, which were accompanied by the high expression of Notch-1 and Hes1 and positively associated with tumor growth(GCSCs vs CD44-negative cells, 2.72 ± 0.25 vs 1.46 ± 0.16, P < 0.05) and microvessel density(MVD)(GCSCs vs CD44-negative cells, 8.15 ± 0.42 vs 3.83 ± 0.49, P < 0.001) in vivo. XTSJ decoction inhibited the viability of both cell types in a dose-dependent manner in vitro. Specifically, a significant difference in the medium-(82.87% ± 6.53%) and high-dose XTSJ groups(77.43% ± 7.34%) was detected at 24 h in the CD44+ GCSCs group compared with the saline group(95.42% ± 5.76%) and the low-dose XTSJ group(90.74% ± 6.57%)(P < 0.05). However, the efficacy of XTSJ decoction was reduced in the CD44- groups; significant differences were only detected in the high-dose XTSJ group at 48 h(78.57% ± 6.94%) and 72 h(72.12% ± 7.68%) when compared with the other CD44- groups(P < 0.05). Notably, these differences were highly consistent with the Notch-1, Hes1, VEGF and Ki-67 expression in these cells. Similarly, in vivo, XTSJ decoction inhibited tumor growth in a dose-dependent manner. A significant difference was observed in the medium(1.76 ± 0.15) and high-dose XTSJ(1.33 ± 0.081) groups compared with the GCSCs control group(2.72 ± 0.25) and the low-dose XTSJ group(2.51 ± 0.25)(P < 0.05). We also detected a remarkable decrease of MVD in the medium-(7.10 ± 0.60) and high-dose XTSJ(5.99 ± 0.47) groups compared with the GCSC control group(8.15 ± 0.42) and the low-dose XTSJ group(8.14 ± 0.46)(P < 0.05). Additionally, CD44 expression was decreased in these groups [medium-(4.43 ± 0.45) and high-dose XTSJ groups(3.56 ± 0.31) vs the GCSC control(5.96 ± 0.46) and low dose XTSJ groups(5.91 ± 0.38)](P < 0.05). The significant differences in Notch-1, Hes1, VEGF and Ki-67 expression highly mirrored the results of XTSJ decoction in inhibiting tumor growth, MVD and CD44 expression.CONCLUSION: Notch-1 may play an important role in regulating the proliferation of GCSCs; XTSJ decoction could attenuate tumor angiogenesis, at least partially, by inhibiting Notch-1.
基金Supported by Grants from the Natural Science Foundation of ChinaNo.2010Z131the Excellent Master Training Fund of the Second Military Medical University
文摘AIM:To investigate the efficacy and potential mechanism of Xiaotan Tongfu granules(XTTF)in stress ulcers.METHODS:One hundred sixty rats were randomly divided into 4 groups(n=10)as follows:the model group(MP group),the control group(CP group),the ranitidine group(RP group)and the XTTF granule group(XP group).Rats in the MP group received no drugs,rats in the CP group received 0.2 mL of a 0.9%sodium chloride solution via oral gavage,and rats in the RP and XP groups received the same volume of ranitidine(50 mg/kg)or XTTF granule(4.9 g/kg).The cold-restraint stress model was applied to induce stress ulcers after 7 consecutive days of drug administration.Afterwards,rats were sacrificed at 0,3,6 and24 h.Gastric pH was measured by a precise pH meter;gastric emptying rate(GER)was measured by using a methylcellulose test meal;myeloperoxidase activity(MPO),macrophage migration inhibitory factor(MIF),proliferating cell nuclear antigen(PCNA),and heat shock protein 70(HSP70)were measured by immunohistochemical staining;and mucosal cell apoptosis was measured by transferase dUTP nick end labeling.RESULTS:In the cold-restraint stress model,the development of stress ulcers peaked at 3 h and basically regressed after 24 h.Gastric lesions were significantly different in the RP and XP groups at each time point.Interestingly,although this index was much lower in the RP group than in the XP group immediately following stress induction(7.00±1.10 vs 10.00±1.79,P<0.05.Concerning gastric pH,between the RP and XP groups,we detected a statistically significant difference immediately after stress induction(0 h:4.56±0.47 vs 3.34±0.28,P<0.05)but not at any of the subsequent time points.For GER,compared to the RP group,GER was remarkably elevated in the XP group because a statistically significant difference was detected(3 h:46.84±2.70 vs 61.16±5.12,P<0.05;6 h:60.96±6.71 vs 73.41±6.16,P<0.05;24 h:77.47±3.17 vs 91.31±4.34,P<0.05).With respect to MPO and MIF,comparisons between the RP and XP groups revealed statistically significant differences at 3 h(MPO:18.94±1.20 vs 13.51±0.89,P<0.05;MIF:150.67±9.85 vs 122.17±5.67,P<0.05)and 6 h(MPO:13.22±1.54 vs 8.83±0.65,P<0.05;MIF:135.50±9.46 vs 109.83±6.40,P<0.05).With regard to HSP70,HSP70 expression was significantly increased in the RP and XP groups at 3 and 6 h compared to the MP and CP groups.In addition,comparing the RP and XP groups also showed statistically significant differences at 3 and 6 h.The expression of PCNA was higher in the RP and XP groups 3 h after stress induction.Between these two groups,small but statistically significant differences were observed at all of the time points(3 h:69.50±21.52 vs 79.33±15.68,P<0.05;6 h:107.83±4.40 vs 121.33±5.71,P<0.05;24 h:125.33±5.65 vs 128.50±14.49,P<0.05)except 0 h.With regard to apoptosis,the apoptotic activity in the RP and XP groups was significantly different from that in the MP and CP groups.The XP group exhibited a higher inhibition of cell apoptosis than the RP group at3 h(232.58±24.51 vs 174.46±10.35,P<0.05)and6 h(164.74±18.31 vs 117.71±12.08,P<0.05).CONCLUSION:The Xiaotan Tongfu granule was demonstrated to be similar to ranitidine in preventing stress ulcers.It exhibited multiple underlying mechanisms and deserves further study.
基金supported by State Key Program of National Natural Science Foundation of China(21733002)Joint Sino-German Research Project(21761132011)Cheung Kong Scholars Programme of China(T2015036)。
文摘Boron-based metal-free catalysts for oxidative dehydrogenation of propane(ODHP)have drawn great attention in both academia and industry due to their impressive activity and olefin selectivity.Herein,the SiO2 and B2O3 sequentially coated honeycomb cordierite catalyst is designed by a two-step wash-coat method with different B2O3 loadings(0.1%–10%)and calcination temperatures(600,700,800℃).SiO2 obtained by TEOS hydrolysis acts as a media layer to bridge the cordierite substrate and boron oxide via abundant Si\\OH groups.The welldeveloped straight channels of honeycomb cordierite make it possible to carry out the reactor under high gas hourly space velocity(GHSV)and the thin wash-coated B2O3 layer can effectively facilitate the pore diffusion on the catalyst.The prepared B2O3/SiO2@HC monolithic catalyst exhibits good catalytic performance at low boron oxide loading and achieves excellent propylene selectivity(86.0%),olefin selectivity(97.6%,propylene and ethylene)and negligible CO2(0.1%)at 16.9%propane conversion under high GHSV of 345,600 ml·(g B2O3)^-1·h^-1,leading to a high propylene space time yield of 15.7 g C3H6·(g B2O3)^-1·h^-1 by suppressing the overoxidation.The obtained results strongly indicate that the boron-based monolithic catalyst can be properly fabricated to warrant the high activity and high throughput with its high gas/surface ratio and straight channels.
基金The study was funded by grants from the Special R&D Program of Ministry of Science and Technology(No.2019YFC1316203)Ministry of Science and Technology(No.2020YFC0844700)Clinical Foundation of Tongji Hospital(No.XXGZBDYJ010).
文摘Summary:The COVID-19 pandemic caused by SARS-CoV2 is characterized by a remarkable variation in clinical severity ranging from a mild illness to a fatal multi-organ disease.Understanding the dysregulated human immune responses in the fatal subjects is critical for management of COVID-19 patients and the pandemic.In this study,we examined the immune cell compositions in the lung tissues and hilar lymph nodes using immunohistochemistry on 6 deceased COVID-19 patients and 4 focal organizing pneumonia(FOP)patients who underwent lung surgery and served as controls.We found a dominant presence of macrophages and a general deficiency of T cells and B cells in the lung tissues from deceased COVID-19 patients.In contrast to the FOP patients,Tfh cells and germinal center formation were largely absent in the draining hilar lymph nodes in the deceased COVID-19 patients.This was correlated with reduced IgM and IgG levels compared to convalescent COVID-19 patients.In summary,our data highlight a defect of germinal center structure in deceased COVID-19 patients leading to an impaired humoral immunity.Understanding the mechanisms of this deficiency will be one of the key points for the management of this epidemic.
基金Supported by National Natural Science Foundation of China,No.81173403
文摘Therapy-related acute myeloid leukemia(t-AML) refers to a heterogeneous group of myeloid neoplasms that develop in patients following extensive exposure to either cytotoxic agents or radiation.The development of t-AML has been reported following treatment of cancers ranging from hematological malignancies to solid tumors; however, to our knowledge, t-AML has never been reported following treatment of gastric cancer.In this study, we report the development of t-acute promyelocytic leukemia in a cT 4N1M0 gastric cancer patient after an approximate 44 mo latency period following treatment with 4 cycles of oxaliplatin(OXP)(85 mg/m2 on day 1) plus capecitabine(1250 mg/m2 orally twice daily on days 1-14) in combination with recombinant human granulocyte-colony stimulating factor treatment.Karyotype analysis of the patient revealed 46,XY,t(15;17)(q22;q21)[15]/46,idem,-9,+add(9)(p22)[2]/46,XY[3], which, according to previous studies, includes some "favorable" genetic abnormalities.The patient was then treated with all-trans retinoic acid(ATRA, 25 mg/m2/d) plus arsenic trioxide(ATO, 10 mg/d) and attained complete remission.Our case illuminated the role of certain cytotoxic agents in the induction of t-AML following gastric cancer treatment.We recommend instituting a mandatory additional evaluation for patients undergoing these therapies in the future.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11874179,11447194,11574114,and 11874177)the Natural Science Foundation of Jilin Province,China(Grant No.20180101289JC)
文摘The accurate equilibrium structures of S_3 and S_3^- are determined by the coupled-cluster method with single, double excitation and perturbative triple excitation(CCSD(T)) with basis sets of aug-cc-pV(n+d)Z(n = T, Q, 5, or 6), complete basis set extrapolation functions with two-parameters and three-parameters, together with considering the contributions due to the core-valence electron correlation, scalar relativistic effects, spin–orbit coupling, and zero-point vibrational corrections. Our calculations show that both the neutral S_3 and anion S_3^- have open forms with C_(2r) vsymmetry. On the basis of the stable geometries, the adiabatic electron affinity of S_3 is determined to be 19041(11) cm^(-1), which is in excellent agreement with the experimental data(19059(7) cm^(-1)). The dependence of geometries and electron affinity on the computation level and physical corrections is discussed. The present computational results are helpful to the experimental molecular spectroscopy and bonding of S_3.
基金Project supported by the National Natural Science Foundation of China(No.11572139)
文摘A field-modulated electroosmotic flow （FMEOF） in a microchannel can be obtained by applying modulating electric fields in a direction perpendicular to the channel wall. Micro-vortexes are generated around the electrodes along with an EOF due to the surface charge on the modulated wall. When polarizable particles are suspended near the electrodes, they experience dielectrophoretic forces due to a non-uniform electric field. In this paper, micro-vortexes and dielectrophoretic forces are combined to achieve separation and trap different sized particles in a continuous flow. Numerical results indicate that by adjusting the driving electric field parallel to the channel wall and the modulating electric field, the ratio of dielectrophoretic and hydrodynamic forces can be altered. One type of particles can be trapped by micro-vortexes （negative dielectrophoresis （DEP））, and the other particles are transported to the downstream so that the particles are separated. The influence of the electrode length and the channel height on the trapping rate is investigated.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0403300)the National Natural Science Foundation of China(Grant Nos.11874179,11574114,and 11874177)the Natural Science Foundation of Jilin Province,China(Grant Nos.20180101289JC)
文摘High-level ab initio calculations of aluminum monoiodide(AlI) molecule are performed by utilizing the multireference configuration interaction plus Davidson correction(MRCI+Q) method. The core-valence correlation(CV) and spin–orbit coupling(SOC) effect are considered. The adiabatic potential energy curves(PECs) of a total of 13 Λ–S states and 24 ? states are computed. The spectroscopic constants of bound states are determined, which are in accordance with the results of the available experimental and theoretical studies. The interactions between the Λ–S states are analyzed with the aid of the spin–orbit matrix elements. Finally, the transition properties including transition dipole moment(TDM),Frank–Condon factors(FCF) and radiative lifetime are obtained based on the computed PEC. Our study sheds light on the electronic structure and spectroscopy of low-lying electronic states of the AlI molecule.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0403300)the National Natural Science Foundation of China(Grant Nos.91750104,11574114,and 11874177)the Natural Science Foundation of Jilin Province,China(Grant No.20160101332JC)
文摘The potential energy curves, spectroscopic constants, and low-lying vibration–rotation levels of ground-state O2 and its cation O2+ and anion O2- were calculated with the explicitly correlated multireference configuration interaction method.The zeroth-order reference wavefunction was treated with the complete active space multiconfigurational self-consistent field method, in which the active space was carefully selected, and an additional molecular orbital πu was added into the full valence active space.The electron correlation of the 1s core in the oxygen atom was considered in the computations.The Davidson correction on molecular energy was considered to account for higher electron excitation.The relativistic effects, including the scalar relativistic effect and spin–orbit coupling, were considered in the computation of potential energy curves.These physical effects on the spectroscopic constants were examined.The low-lying levels of vibration–rotation spectra of O2 and its ions were determined based on the computed potential energy curves.Comparisons with available experiments were made and excellent agreement was obtained for the vibrational and rotational parameters.The spectroscopic constants and vibration–rotation spectrum of O2-, which is sparse in experiments, were provided.Our study will shed some light on further theoretical and experimental studies on these simple but important molecular systems.
基金supported in part by the Project Funded by ABB and U.S.National Science Foundation(ECCS-1509666)
文摘Grid integration of wind power is essential to reduce fossil fuel usage but challenging in view of the intermittent nature of wind.Recently,we developed a hybrid Markovian and interval approach for the unit commitment and economic dispatch problem where power generation of conventional units is linked to local wind states to dampen the effects of wind uncertainties.Also,to reduce complexity,extreme and expected states are considered as interval modeling.Although this approach is effective,the fact that major wind farms are often located in remote locations and not accompanied by conventional units leads to conservative results.Furthermore,weights of extreme and expected states in the objective function are difficult to tune,resulting in significant differences between optimization and simulation costs.In this paper,each remote wind farm is paired with a conventional unit to dampen the effects of wind uncertainties without using expensive utility-scaled battery storage,and extra constraints are innovatively established to model pairing.Additionally,proper weights are derived through a novel quadratic fit of cost functions.The problem is solved by using a creative integration of our recent surrogate Lagrangian relaxation and branch-and-cut.Results demonstrate modeling accuracy,computational efficiency,and significant reduction of conservativeness of the previous approach.
基金Project supported by the National Natural Science Foundation of China(Grant No.11572139).
文摘Dielectrophoresis(DEP)technology has become important application of microfluidic technology to manipulate particles.By using a local modulating electric field to control the combination of electroosmotic microvortices and DEP,our group proposed a device using a direct current(DC)electric field to achieve continuous particle separation.In this paper,the influence of the Joule heating effect on the continuous separation of particles is analyzed.Results show that the Joule heating effect is caused by the local electric field,and the Joule heating effect caused by adjusting the modulating voltage is more significant than that by driving voltage.Moreover,a non-uniform temperature distribution exists in the channel due to the Joule heating effect,and the temperature is the highest at the midpoint of the modulating electrodes.The channel flux can be enhanced,and the enhancement of both the channel flux and temperature is more obvious for a stronger Joule heating effect.In addition,the ability of the vortices to trap particles is enhanced since a larger DEP force is exerted on the particles with the Joule heating effect;and the ability of the vortex to capture particles is stronger with a stronger Joule heating effect.The separation efficiency can also be increased because perfect separation is achieved at a higher channel flux.Parameter optimization of the separation device,such as the convective heat transfer coefficient of the channel wall,the length of modulating electrode,and the width of the channel,is performed.
基金Project supported by the National Natural Science Foundation of China(No.11572139)。
文摘The dielectrophoretic technology has been one of the most frequently applied microfluidic technologies to manipulate particles.The way of a combination of controlled electroosmotic micro-vortices and dielectrophoresis to manipulate particles of different sizes was proposed in our previous work.However,the thickness of the modulating electrode is neglected.In practice,when the thickness of the modulating electrode increases,the channel flux increases,while the ability of the vortex to capture the particles reduces.In this study,a new method combining the field-modulating electroosmotic vortex and the insulating post is proposed to improve the manipulating capability of the field-modulated electroosmotic vortex to particles.The results indicate that there are three great advantages as the insulating post is placed on the channel wall on the same side of the modulating electrode.First,the capturing ability of the vortex to particles is greater due to the reduction of channel flux and the squeezing effect.Second,the range of regulating channel flux to achieve the optimal separation is extended.Third,the separation efficiency improves since the perfect separation can be achieved at a higher flow rate.Furthermore,the effects of the location and the size of the insulating post on particle separation are analyzed in detail.The present work could provide the reference for the application of the DEP technology.
