Chronic hepatitis B(CHB)is a significant public health problem worldwide.The aim of the present review is to summarize the actual trends in the management of CHB in pregnant women.The prevalence of hepatitis B virus(H...Chronic hepatitis B(CHB)is a significant public health problem worldwide.The aim of the present review is to summarize the actual trends in the management of CHB in pregnant women.The prevalence of hepatitis B virus(HBV)infection in pregnant women is usually comparable to that in the general population in the corresponding geographic area.All women have to be screened for hepatitis B surface antigen(HBsAg)during pregnancy.Additional examinations of pregnant women with CHB may include maternal hepatitis B e antigen,HBV viral load,alanine aminotransferase level,and HBsAg level.The management of pregnancy depends on the phase of the HBV infection,which has to be determined before pregnancy.In women of childbearing age with CHB,antiviral therapy can pursue two main goals:Treatment of active CHB,and vertical transmission prevention.During pregnancy,tenofovir is the drug of choice in both cases.A combination of hepatitis B immunoglobulin and vaccine against hepatitis B should be administered within the first 12 h to all infants born to mothers with CHB.In such cases,there are no contraindications to breastfeeding.展开更多
In the recent years,a dramatic boost of the research is observed at the junction of photonics,machine learning and artifi-cial intelligence.A new methodology can be applied to the description of a variety of photonic ...In the recent years,a dramatic boost of the research is observed at the junction of photonics,machine learning and artifi-cial intelligence.A new methodology can be applied to the description of a variety of photonic systems including optical waveguides,nanoantennas,and metasurfaces.These novel approaches underpin the fundamental principles of light-matter interaction developed for a smart design of intelligent photonic devices.Artificial intelligence and machine learn-ing penetrate rapidly into the fundamental physics of light,and they provide effective tools for the study of the field of metaphotonics driven by optically induced electric and magnetic resonances.Here we overview the evaluation of meta-photonics induced by artificial intelligence and present a summary of the concepts of machine learning with some specif-ic examples developed and demonstrated for metasystems and metasurfaces.展开更多
The study of resonant dielectric nanostructures with a high refractive index is a new research direction in the nanoscale optics and metamaterial-inspired nanophotonics.Because of the unique optically induced electric...The study of resonant dielectric nanostructures with a high refractive index is a new research direction in the nanoscale optics and metamaterial-inspired nanophotonics.Because of the unique optically induced electric and magnetic Mie resonances,high-index nanoscale structures are expected to complement or even replace different plasmonic components in a range of potential applications.We study a strong coupling between modes of a single subwavelength high-index dielectric resonator and analyze the mode transformation and Fano resonances when the resonator’s aspect ratio varies.We demonstrate that strong mode coupling results in resonances with high-quality factors,which are related to the physics of bound states in the continuum when the radiative losses are almost suppressed due to the Friedrich–Wintgen scenario of destructive interference.We explain the physics of these states in terms of multipole decomposition,and show that their appearance is accompanied by a drastic change in the far-field radiation pattern.We reveal a fundamental link between the formation of the high-quality resonances and peculiarities of the Fano parameter in the scattering cross-section spectra.Our theoretical findings are confirmed by microwave experiments for the scattering of high-index cylindrical resonators with a tunable aspect ratio.The proposed mechanism of the strong mode coupling in single subwavelength high-index resonators accompanied by resonances with high-quality factors helps to extend substantially functionalities of all-dielectric nanophotonics,which opens horizons for active and passive nanoscale metadevices.展开更多
Optical bound states in the continuum(BICs)provide a way to engineer very narrow resonances in photonic crystals.The extended interaction time in these systems is particularly promising for the enhancement of nonlinea...Optical bound states in the continuum(BICs)provide a way to engineer very narrow resonances in photonic crystals.The extended interaction time in these systems is particularly promising for the enhancement of nonlinear optical processes and the development of the next generation of active optical devices.However,the achievable interaction strength is limited by the purely photonic character of optical BICs.Here,we mix the optical BIC in a photonic crystal slab with excitons in the atomically thin semiconductor MoSe_(2) to form nonlinear exciton-polaritons with a Rabi splitting of 27 meV,exhibiting large interaction-induced spectral blueshifts.The asymptotic BIC-like suppression of polariton radiation into the far field toward the BIC wavevector,in combination with effective reduction of the excitonic disorder through motional narrowing,results in small polariton linewidths below 3 meV.Together with a strongly wavevector-dependent Q-factor,this provides for the enhancement and control of polariton–polariton interactions and the resulting nonlinear optical effects,paving the way toward tuneable BIC-based polaritonic devices for sensing,lasing,and nonlinear optics.展开更多
Recent days,aggregatable nanoparticles,which can specifically respond to certain stimulus,have shown great potential in tumor-targeted drug delivery with prolonged retention and deeper penetration.In this review,we su...Recent days,aggregatable nanoparticles,which can specifically respond to certain stimulus,have shown great potential in tumor-targeted drug delivery with prolonged retention and deeper penetration.In this review,we summarize recent advances in design of aggregatable nanoparticles by different stimuli.Internal(pH and enzyme)and external(light,temperature and ROS)stimuli are introduced for a comprehensive description.Moreover,the aggregated nanoparticles usually exhibit photothermal,photoacoustic,PET and enhanced MRI contrast,which is also described.In the end,we discuss about the potential applications and challenges for the future clinical translation.展开更多
Nanocrystalline yttrium vanadate doped with europium ions powders were synthesized via sol-gel method based on decomposition of metal-polymer complex. X-ray diffraction analysis showed that samples had pure tetragonal...Nanocrystalline yttrium vanadate doped with europium ions powders were synthesized via sol-gel method based on decomposition of metal-polymer complex. X-ray diffraction analysis showed that samples had pure tetragonal phase without any impurities. Scanning electron microscopy and static light scattering technique were used to study morphology and size of prepared nanoparticles. Average diameter of the nanoparticles was about 40 nm. The changes in structural and luminescence properties were observed as a function of the first and second calcination temperature. The optimal conditions for synthesis of nanoparticles were determined as Т1=500℃, t1=1 h; Т2=950 ℃, t2=1.5 h. The effect of different media surrounding the nanoparticles on their luminescence properties and lifetime was investigated and discussed in terms of effective refractive index. It was found that the observed lifetime of YVO4：Eu^3＋ 5 at.% nanophosphor was decreased from 0.64 ms in air（nmed=1） to 0.45 ms in chalcogenide glass As39S61（nmed=2.39）.展开更多
GISAID is a global data science initiative and the primary source of genomic and associated metadata of all influenza viruses,Respiratory Syncytial Virus(RSV)and severe acute respiratory syndrome coronavirus 2(SARS-Co...GISAID is a global data science initiative and the primary source of genomic and associated metadata of all influenza viruses,Respiratory Syncytial Virus(RSV)and severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the pandemic coronavirus causing coronavirus disease 2019(COVID-19).GISAID’s publicly accessible data sharing platform enables collaboration of over 42,000 participating researchers from 198 nations and data generators from over 3,500 institutions across the globe.Since the first wholegenome sequences were made available by China CDC through GISAID on January 10.展开更多
AIM:To investigate the effect of local intestinal perfusion with hypertonic saline(HTS) on intestinal ischemia-reperfusion injury(IRI) in bothex vivo andin vivo rat models.METHODS:All experiments were performed on mal...AIM:To investigate the effect of local intestinal perfusion with hypertonic saline(HTS) on intestinal ischemia-reperfusion injury(IRI) in bothex vivo andin vivo rat models.METHODS:All experiments were performed on male Wistar rats anesthetized with pentobarbital sodium given intraperitoneally at a dose of 60 mg/kg.Ex vivo vascularly perfused rat intestine was subjected to 60-min ischemia and either 30-min reperfusion with isotonic buffer(controls),or 5 min with HTS of 365 or 415 mOsm/L osmolarity(HTS 365mOsm or HTS 415mOsm,respectively) followed by 25-min reperfusion with isotonic buffer.The vascular intestinal perfusate flow(IPF) rate was determined by collection of the effluent from the portal vein in a calibrated tube.Spontaneous intestinal contraction rate was monitored throughout.Irreversible intestinal injury or area of necrosis(AN) was evaluated histochemically using 2.3.5-triphenyltetrazolium chloride staining.In vivo,30-min ischemia was followed by either 30-min blood perfusion or 5-min reperfusion with HTS 365mOsm through the superior mesenteric artery(SMA) followed by 25-min blood perfusion.Arterial blood pressure(BP) was measured in the common carotid artery using a miniature pressure transducer.Histological injury was evaluated in both preparations using the Chui score.RESULTS:Ex vivo,intestinal IRI resulted in a reduction in the IPF rate during reperfusion(P < 0.05 vs sham).The postischemic recovery of the IPF rate did not differ between the controls and the HTS 365mOsm group.In the HTS 415mOsm group,postischemic IPF rates were lower than in the controls and the HTS 365mOsm group(P < 0.05).The intestinal contraction rate was similar at baseline in all groups.An increase in this parameter was observed during the first 10 min of reperfusion in the control group as compared to the sham-treated group,but no such increase was seen in the HTS 365mOsm group.In controls,AN averaged 14.8% ± 5.07% of the total tissue volume.Administration of HTS 365mOsm for 5 min after 60-min ischemia resulted in decrease in展开更多
Ti Ni alloys, with their unique shape memory effects and super elastic properties, occupy an indispensable place in the family of metallic biomaterials. In the past years, surface treatment is the main technique to im...Ti Ni alloys, with their unique shape memory effects and super elastic properties, occupy an indispensable place in the family of metallic biomaterials. In the past years, surface treatment is the main technique to improve the bioinert nature of microcrystalline Ti Ni alloys and inhibit on the release of toxic nickel ions to obtain excellent osteogenesis and osseointegration function. In the present study, nanocrystalline Ti49.2Ni50.8 alloy has been fabricated via equal channel angular pressing(ECAP), and the in vitro and in vivo studies revealed that it had enhanced cell viability, adhesion, proliferation, ALP(Alkaline phosphatase)activity and mineralization, and increased periphery thickness of new bone, in comparison to the commercial coarse-grained counterpart. These findings indicate that the reduction of grain size is beneficial to increasing the biocompatibility of Ti49.2Ni50.8 shape memory alloy.展开更多
A decadal change in summer rainfall in the Asian inland plateau（AIP） region is identified around 1999. This decadal change is characterized by an abrupt decrease in summer rainfall of about 15.7% of the climatologic...A decadal change in summer rainfall in the Asian inland plateau（AIP） region is identified around 1999. This decadal change is characterized by an abrupt decrease in summer rainfall of about 15.7% of the climatological average amount,leading to prolonged drought in the Asian inland plateau region. Both the surface air temperature and potential evapotranspiration in the AIP show a significant increase, while the soil moisture exhibits a decrease, after the late 1990s. Furthermore,the normalized difference vegetation index shows an apparent decreasing trend during 1999–2007. Three different drought indices—the standardized precipitation index, the standardized precipitation evapotranspiration index, and the self-calibrating Palmer drought severity index—present pronounced climate anomalies during 1999–2007, indicating dramatic drought exacerbation in the region after the late 1990s. This decadal change in the summer rainfall may be attributable to a wave-like teleconnection pattern from Western Europe to Asia. A set of model sensitivity experiments suggests that the summer warming sea surface temperature in the North Atlantic could induce this teleconnection pattern over Eurasia, resulting in recent drought in the AIP region.展开更多
Matters are generally classified within four states:solid,liquid,gas,and plasma.Three of the four states of matter(solid,gas,and plasma)have been used for THz wave generation with short laser pulse excitation for deca...Matters are generally classified within four states:solid,liquid,gas,and plasma.Three of the four states of matter(solid,gas,and plasma)have been used for THz wave generation with short laser pulse excitation for decades,including the recent vigorous development of THz photonics in gases(air plasma).However,the demonstration of THz generation from liquids was conspicuously absent.It is well known that water,the most common liquid,is a strong absorber in the far infrared range.Therefore,liquid water has historically been sworn off as a source for THz radiation.Recently,broadband THz wave generation from a flowing liquid target has been experimentally demonstrated through laser-induced microplasma.The liquid target as the THz source presents unique properties.Specifically,liquids have the comparable material density to that of solids,meaning that laser pulses over a certain area will interact with three orders more molecules than an equivalent cross-section of gases.In contrast with solid targets,the fluidity of liquid allows every laser pulse to interact with a fresh area on the target,meaning that material damage or degradation is not an issue with the high-repetition rate intense laser pulses.These make liquids very promising candidates for the investigation of high-energy-density plasma,as well as the possibility of being the next generation of THz sources.展开更多
BACKGROUND Lung damage in systemic juvenile arthritis(sJIA)is one of the contemporary topics in pediatric rheumatology.Several previous studies showed the severe course and fatal outcomes in some patients.The informat...BACKGROUND Lung damage in systemic juvenile arthritis(sJIA)is one of the contemporary topics in pediatric rheumatology.Several previous studies showed the severe course and fatal outcomes in some patients.The information about interstitial lung disease(ILD)in the sJIA is scarce and limited to a total of 100 cases.AIM To describe the features of sJIA patients with ILD in detail.METHODS In the present retrospective cohort study,information about 5 patients less than 18-years-old with sJIA and ILD were included.The diagnosis of sJIA was made according to the current 2004 and new provisional International League of Associations for Rheumatology criteria 2019.ILD was diagnosed with chest computed tomography with the exclusion of other possible reasons for concurrent lung involvement.Macrophage activation syndrome(MAS)was diagnosed with HLH-2004 and 2016 EULAR/ACR/PRINTO Classification Criteria and hScores were calculated during the lung involvement.RESULTS The onset age of sJIA ranged from 1 year to 10 years.The time interval before ILD ranged from 1 mo to 3 years.The disease course was characterized by the prevalence of the systemic features above articular involvement,intensive rash(100%),persistent and very active MAS(hScore range:194-220)with transaminitis(100%),and respiratory symptoms(100%).Only 3 patients(60%)developed a clubbing phenomenon.All patients(100%)had pleural effusion and 4 patients(80%)had pericardial effusion at the disease onset.Two patients(40%)developed pulmonary arterial hypertension.Infusion-related reactions to tocilizumab were observed in 3(60%)of the patients.One patient with trisomy 21 had a fatal disease course.Half of the remaining patients had sJIA remission and 2 patients had improvement.Lung disease improved in 3 patients(75%),but 1 of them had initial deterioration of lung involvement.One patient who has not achieved the sJIA remission had the progressed course of ILD.No cases of hyper-eosinophilia were noted.Four patients(80%)received canakinumab and one(20%)tocilizumab at the last 展开更多
Porous metal–organic frameworks(MOFs) have been recently discovered to be efficient catalysts for energy applications and green technologies. Here, we report on a scalable catalytic platform using Cu–based MOFs for ...Porous metal–organic frameworks(MOFs) have been recently discovered to be efficient catalysts for energy applications and green technologies. Here, we report on a scalable catalytic platform using Cu–based MOFs for electrocatalytic alkaline hydrogen evolution reaction. First, the solvothermal synthesis of Cu–BTC MOFs(BTC = 1,3,5–benzenetricarboxylate) at 85 ℃ and a 1:60 ligand–to–solvent ratio allowed for minimizing the chemical consumption. Second, the obtained platform demonstrated enhanced electrochemical performance compared with commercially available Cu–based MOFs, with a potential of –230 versus –232 eV, logarithm of the current density of –3.6 versus –4.2 cm2, and electrochemical surface area of 75 versus 25 cm2per cm2of geometric area, respectively. Morphological and Raman analyses also revealed that the high concentration of defects in the obtained submicron Cu–BTC MOFs can contribute to their improved catalytic performance. Thus, our findings pave the way to the low–cost synthesis of energy–efficient MOF–based catalysts for hydrogen production.展开更多
We fit various color–magnitude diagrams(CMDs) of the high-latitude Galactic globular clusters NGC 5024(M53),NGC 5053,NGC 5272(M3),NGC 5466,and NGC 7099(M30) by isochrones from the Dartmouth Stellar Evolution Database...We fit various color–magnitude diagrams(CMDs) of the high-latitude Galactic globular clusters NGC 5024(M53),NGC 5053,NGC 5272(M3),NGC 5466,and NGC 7099(M30) by isochrones from the Dartmouth Stellar Evolution Database and Bag of Stellar Tracks and Isochrones for α–enrichment [α/Fe] = +0.4.For the CMDs,we use data sets from Hubble Space Telescope,Gaia,and other sources utilizing,at least,25 photometric filters for each cluster.We obtain the following characteristics with their statistical uncertainties for NGC 5024,NGC 5053,NGC 5272,NGC 5466,and NGC 7099,respectively:metallicities [Fe/H] =-1.93 ± 0.02,-2.08 ± 0.03,-1.60 ± 0.02,-1.95 ± 0.02,and-2.07 ± 0.04 dex with their systematic uncertainty 0.1 dex;ages 13.00 ± 0.11,12.70 ± 0.11,11.63 ± 0.07,12.15 ± 0.11,and 12.80 ± 0.17 Gyr with their systematic uncertainty 0.8 Gyr;distances(systematic uncertainty added) 18.22 ± 0.06 ± 0.60,16.99 ± 0.06 ± 0.56,10.08 ± 0.04 ± 0.33,15.59 ±0.03 ± 0.51,and 8.29 ± 0.03 ± 0.27 kpc;reddenings E(B-V) = 0.023 ± 0.004,0.017 ± 0.004,0.023 ± 0.004,0.023 ± 0.003,and 0.045 ± 0.002 mag with their systematic uncertainty 0.01 mag;extinctions AV= 0.08 ± 0.01,0.06 ± 0.01,0.08 ± 0.01,0.08 ± 0.01,and 0.16 ± 0.01 mag with their systematic uncertainty 0.03 mag,which suggest the total Galactic extinction AV= 0.08 across the whole Galactic dust to extragalactic objects at the North Galactic Pole.The horizontal branch morphology difference of these clusters is explained by their different metallicity,age,mass-loss efficiency,and loss of low-mass members in the evolution of the core-collapse cluster NGC 7099 and loose clusters NGC 5053 and NGC 5466.展开更多
Despite well-known limitations,mice remain useful as model animals to study tuberculosis(TB)pathogenesis,the basic immune response,the extent of lung pathology as well as efficacy of new drugs against Mycobacterium tu...Despite well-known limitations,mice remain useful as model animals to study tuberculosis(TB)pathogenesis,the basic immune response,the extent of lung pathology as well as efficacy of new drugs against Mycobacterium tuberculosis[1,2].There are four routes of tuberculosis infection in mice:aerosol generation and exposition,intravenous injection,intranasal administration,and subcutaneous administration[3].展开更多
Modern trends in beam-driven radiation sources include the interaction of Cherenkov wakefields in open-ended circular waveguides with complicated dielectric linings, with a three-layer dielectric capillary recently pr...Modern trends in beam-driven radiation sources include the interaction of Cherenkov wakefields in open-ended circular waveguides with complicated dielectric linings, with a three-layer dielectric capillary recently proposed to reduce radiation divergence being a representative example [Opt. Lett. 45 5416(2020)]. We present a rigorous approach that allows for an analytical description of the electromagnetic processes that occur when the structure is excited by a single waveguide TM mode. In other words, the corresponding canonical waveguide diffraction problem is solved in a rigorous formulation. This is a continuation of our previous papers which considered simpler cases with a homogeneous or two-layer dielectric filling. Here we use the same analytical approach based on the Wiener–Hopf–Fock technique and deal with the more complicated case of a three-layer dielectric lining. Using the obtained rigorous solution, we discuss the possibility of manipulating the far-field radiation pattern using a third layer made of a low permittivity material.展开更多
The Gatchina discharge phenomenon holds significant promise as a laboratory model for simulating ball lightning.However,crucial aspects concerning the plasma components of the resulting afterglow remain unresolved.Not...The Gatchina discharge phenomenon holds significant promise as a laboratory model for simulating ball lightning.However,crucial aspects concerning the plasma components of the resulting afterglow remain unresolved.Notably,the measurement of the electron density,a critical parameter,has not been fully achieved thus far.In this study,microwave diagnostics and video recording were employed during a pulsed Gatchina discharge,along with synchronous measurement of discharge current and voltage.Distinct antennas were positioned at different heights to enable separate diagnosis of the discharge and the ensuing long-lived afterglow.The findings revealed that during the active phase of the Gatchina discharge,the plasma density was substantial enough to cause reflection of an electromagnetic wave with a frequency of 20 GHz from this highly conductive object.In the afterglow,the signal experienced only a moderate weakening of 10–20 percent,facilitating the determination of the time dependence of average electron density during the afterglow's passage between the two antennas.These measurements verified the unusually slow plasma decay in the afterglow of the Gatchina discharge,suggesting the potential significance of chemi-ionisation processes involving long-lived(metastable)particles.展开更多
文摘Chronic hepatitis B(CHB)is a significant public health problem worldwide.The aim of the present review is to summarize the actual trends in the management of CHB in pregnant women.The prevalence of hepatitis B virus(HBV)infection in pregnant women is usually comparable to that in the general population in the corresponding geographic area.All women have to be screened for hepatitis B surface antigen(HBsAg)during pregnancy.Additional examinations of pregnant women with CHB may include maternal hepatitis B e antigen,HBV viral load,alanine aminotransferase level,and HBsAg level.The management of pregnancy depends on the phase of the HBV infection,which has to be determined before pregnancy.In women of childbearing age with CHB,antiviral therapy can pursue two main goals:Treatment of active CHB,and vertical transmission prevention.During pregnancy,tenofovir is the drug of choice in both cases.A combination of hepatitis B immunoglobulin and vaccine against hepatitis B should be administered within the first 12 h to all infants born to mothers with CHB.In such cases,there are no contraindications to breastfeeding.
基金supported by Priority 2030 Federal Academic Leadership Programsupport from the Foundation for the Advancement of Theoretical Physics and Mathematics“BASIS”+4 种基金support from the Australian Research Council(grant CE170100012)support from the Strategic Fund of the Australian National UniversityThe Australian Research Council(grants DP200101168 and DP210101292)the Russian Science Foundation(grant 21-72-30018)the US Army International Office(grant FA5209-21-P0034)。
文摘In the recent years,a dramatic boost of the research is observed at the junction of photonics,machine learning and artifi-cial intelligence.A new methodology can be applied to the description of a variety of photonic systems including optical waveguides,nanoantennas,and metasurfaces.These novel approaches underpin the fundamental principles of light-matter interaction developed for a smart design of intelligent photonic devices.Artificial intelligence and machine learn-ing penetrate rapidly into the fundamental physics of light,and they provide effective tools for the study of the field of metaphotonics driven by optically induced electric and magnetic resonances.Here we overview the evaluation of meta-photonics induced by artificial intelligence and present a summary of the concepts of machine learning with some specif-ic examples developed and demonstrated for metasystems and metasurfaces.
基金We acknowledge fruitful discussions with H.Atwater,I.V.Shadrivov,P.A.Belov,A.N.Poddubny,A.Polman,and A.Moroz.The numerical calculations were performed with support from the Ministry of Education and Science of the Russian Federation(Project 3.1500.2017/4.6)the Australian Research Council.The experimental study of the cylinder SCS in the microwave frequency range was supported by the Russian Science Foundation(17-79-20379)The analytical calculations with resonant-state expansion method were performed with support from the Russian Science Foundation(17-12-01581)。
文摘The study of resonant dielectric nanostructures with a high refractive index is a new research direction in the nanoscale optics and metamaterial-inspired nanophotonics.Because of the unique optically induced electric and magnetic Mie resonances,high-index nanoscale structures are expected to complement or even replace different plasmonic components in a range of potential applications.We study a strong coupling between modes of a single subwavelength high-index dielectric resonator and analyze the mode transformation and Fano resonances when the resonator’s aspect ratio varies.We demonstrate that strong mode coupling results in resonances with high-quality factors,which are related to the physics of bound states in the continuum when the radiative losses are almost suppressed due to the Friedrich–Wintgen scenario of destructive interference.We explain the physics of these states in terms of multipole decomposition,and show that their appearance is accompanied by a drastic change in the far-field radiation pattern.We reveal a fundamental link between the formation of the high-quality resonances and peculiarities of the Fano parameter in the scattering cross-section spectra.Our theoretical findings are confirmed by microwave experiments for the scattering of high-index cylindrical resonators with a tunable aspect ratio.The proposed mechanism of the strong mode coupling in single subwavelength high-index resonators accompanied by resonances with high-quality factors helps to extend substantially functionalities of all-dielectric nanophotonics,which opens horizons for active and passive nanoscale metadevices.
基金funding from the Ministry of Education and Science of the Russian Federation through Megagrant No.14.Y26.31.0015the UK EPSRC grant EP/P026850/1+4 种基金the project“Hybrid polaritonics”of Icelandic Science Foundationfunded by RFBR according to the research project№18-32-00527funded by RFBR,project No 19-32-90269partly funded by the Russian Science Foundation(Grant No.19-72-30003)support from the Government of the Russian Federation through the ITMO Fellowship and Professorship Program.
文摘Optical bound states in the continuum(BICs)provide a way to engineer very narrow resonances in photonic crystals.The extended interaction time in these systems is particularly promising for the enhancement of nonlinear optical processes and the development of the next generation of active optical devices.However,the achievable interaction strength is limited by the purely photonic character of optical BICs.Here,we mix the optical BIC in a photonic crystal slab with excitons in the atomically thin semiconductor MoSe_(2) to form nonlinear exciton-polaritons with a Rabi splitting of 27 meV,exhibiting large interaction-induced spectral blueshifts.The asymptotic BIC-like suppression of polariton radiation into the far field toward the BIC wavevector,in combination with effective reduction of the excitonic disorder through motional narrowing,results in small polariton linewidths below 3 meV.Together with a strongly wavevector-dependent Q-factor,this provides for the enhancement and control of polariton–polariton interactions and the resulting nonlinear optical effects,paving the way toward tuneable BIC-based polaritonic devices for sensing,lasing,and nonlinear optics.
基金supported by the National Natural Science Foundation of China(No.81961138009)the Young Elite Scientists Sponsorship Program by CAST(No.2017QNR001)+1 种基金the Fundamental Research Funds for the Central Universities,111 Project(No.B18035)RFBR and National Natural Science Foundation of China Collaboration Project(No.19-58-55001)。
文摘Recent days,aggregatable nanoparticles,which can specifically respond to certain stimulus,have shown great potential in tumor-targeted drug delivery with prolonged retention and deeper penetration.In this review,we summarize recent advances in design of aggregatable nanoparticles by different stimuli.Internal(pH and enzyme)and external(light,temperature and ROS)stimuli are introduced for a comprehensive description.Moreover,the aggregated nanoparticles usually exhibit photothermal,photoacoustic,PET and enhanced MRI contrast,which is also described.In the end,we discuss about the potential applications and challenges for the future clinical translation.
文摘Nanocrystalline yttrium vanadate doped with europium ions powders were synthesized via sol-gel method based on decomposition of metal-polymer complex. X-ray diffraction analysis showed that samples had pure tetragonal phase without any impurities. Scanning electron microscopy and static light scattering technique were used to study morphology and size of prepared nanoparticles. Average diameter of the nanoparticles was about 40 nm. The changes in structural and luminescence properties were observed as a function of the first and second calcination temperature. The optimal conditions for synthesis of nanoparticles were determined as Т1=500℃, t1=1 h; Т2=950 ℃, t2=1.5 h. The effect of different media surrounding the nanoparticles on their luminescence properties and lifetime was investigated and discussed in terms of effective refractive index. It was found that the observed lifetime of YVO4：Eu^3＋ 5 at.% nanophosphor was decreased from 0.64 ms in air（nmed=1） to 0.45 ms in chalcogenide glass As39S61（nmed=2.39）.
文摘GISAID is a global data science initiative and the primary source of genomic and associated metadata of all influenza viruses,Respiratory Syncytial Virus(RSV)and severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the pandemic coronavirus causing coronavirus disease 2019(COVID-19).GISAID’s publicly accessible data sharing platform enables collaboration of over 42,000 participating researchers from 198 nations and data generators from over 3,500 institutions across the globe.Since the first wholegenome sequences were made available by China CDC through GISAID on January 10.
基金Supported by Grant 2359.2012.7 of the President of the Russian Federation for the Support of Leading Scientific Groups
文摘AIM:To investigate the effect of local intestinal perfusion with hypertonic saline(HTS) on intestinal ischemia-reperfusion injury(IRI) in bothex vivo andin vivo rat models.METHODS:All experiments were performed on male Wistar rats anesthetized with pentobarbital sodium given intraperitoneally at a dose of 60 mg/kg.Ex vivo vascularly perfused rat intestine was subjected to 60-min ischemia and either 30-min reperfusion with isotonic buffer(controls),or 5 min with HTS of 365 or 415 mOsm/L osmolarity(HTS 365mOsm or HTS 415mOsm,respectively) followed by 25-min reperfusion with isotonic buffer.The vascular intestinal perfusate flow(IPF) rate was determined by collection of the effluent from the portal vein in a calibrated tube.Spontaneous intestinal contraction rate was monitored throughout.Irreversible intestinal injury or area of necrosis(AN) was evaluated histochemically using 2.3.5-triphenyltetrazolium chloride staining.In vivo,30-min ischemia was followed by either 30-min blood perfusion or 5-min reperfusion with HTS 365mOsm through the superior mesenteric artery(SMA) followed by 25-min blood perfusion.Arterial blood pressure(BP) was measured in the common carotid artery using a miniature pressure transducer.Histological injury was evaluated in both preparations using the Chui score.RESULTS:Ex vivo,intestinal IRI resulted in a reduction in the IPF rate during reperfusion(P < 0.05 vs sham).The postischemic recovery of the IPF rate did not differ between the controls and the HTS 365mOsm group.In the HTS 415mOsm group,postischemic IPF rates were lower than in the controls and the HTS 365mOsm group(P < 0.05).The intestinal contraction rate was similar at baseline in all groups.An increase in this parameter was observed during the first 10 min of reperfusion in the control group as compared to the sham-treated group,but no such increase was seen in the HTS 365mOsm group.In controls,AN averaged 14.8% ± 5.07% of the total tissue volume.Administration of HTS 365mOsm for 5 min after 60-min ischemia resulted in decrease in
基金supported by the National Key R&D Program of China (No. 2018YFC1106600)National Natural Science Foundation of China (NSFC)+4 种基金the Russian Foundation for Basic Research (RFBR) NSFC-RFBR Cooperative Project (No. 51611130054)the National Natural Science Foundation of China (Nos. 51431002 and 51871004)the National Natural Science Foundation of China (NSFC)the Research Grants Council (RGC) of Hong Kong NSFC-RGC Joint Research Scheme (Grant No. 5161101031)the financial support from Saint Petersburg State University in the framework of Call 3 project (id 26130576)
文摘Ti Ni alloys, with their unique shape memory effects and super elastic properties, occupy an indispensable place in the family of metallic biomaterials. In the past years, surface treatment is the main technique to improve the bioinert nature of microcrystalline Ti Ni alloys and inhibit on the release of toxic nickel ions to obtain excellent osteogenesis and osseointegration function. In the present study, nanocrystalline Ti49.2Ni50.8 alloy has been fabricated via equal channel angular pressing(ECAP), and the in vitro and in vivo studies revealed that it had enhanced cell viability, adhesion, proliferation, ALP(Alkaline phosphatase)activity and mineralization, and increased periphery thickness of new bone, in comparison to the commercial coarse-grained counterpart. These findings indicate that the reduction of grain size is beneficial to increasing the biocompatibility of Ti49.2Ni50.8 shape memory alloy.
基金supported jointly by the National Key Research and Development Program(Grant No.2016YFA0600604)the National Natural Science Foundation of China(Grant No.41461144001 and 41375046)+1 种基金Open Research Fund Program of Key Laboratory of Meteorological Disaster of Ministry of Education(Nanjing University of Information Science and Technology)Grant No.KLME1403the Chinese Academy of Sciences President’s International Fellowship Initiative
文摘A decadal change in summer rainfall in the Asian inland plateau（AIP） region is identified around 1999. This decadal change is characterized by an abrupt decrease in summer rainfall of about 15.7% of the climatological average amount,leading to prolonged drought in the Asian inland plateau region. Both the surface air temperature and potential evapotranspiration in the AIP show a significant increase, while the soil moisture exhibits a decrease, after the late 1990s. Furthermore,the normalized difference vegetation index shows an apparent decreasing trend during 1999–2007. Three different drought indices—the standardized precipitation index, the standardized precipitation evapotranspiration index, and the self-calibrating Palmer drought severity index—present pronounced climate anomalies during 1999–2007, indicating dramatic drought exacerbation in the region after the late 1990s. This decadal change in the summer rainfall may be attributable to a wave-like teleconnection pattern from Western Europe to Asia. A set of model sensitivity experiments suggests that the summer warming sea surface temperature in the North Atlantic could induce this teleconnection pattern over Eurasia, resulting in recent drought in the AIP region.
基金supported by the Army Research Office(Grant no.W911NF-17-1-0428)Air Force Office of Scientific Research(Grant no.FA9550-18-1-0357),and National Science Foundation(Grant no.ECCS1916068)+2 种基金A.Tcypkin and S.Kozlov are supported by the Russian Science Foundation(Grant no.19-12-00097).L.Zhang and C.Zhang are supported by the Beijing Natural Science Foundation(Grant no.JQ18015)the National Natural Science Foundation of China(Grant no.12074272).
文摘Matters are generally classified within four states:solid,liquid,gas,and plasma.Three of the four states of matter(solid,gas,and plasma)have been used for THz wave generation with short laser pulse excitation for decades,including the recent vigorous development of THz photonics in gases(air plasma).However,the demonstration of THz generation from liquids was conspicuously absent.It is well known that water,the most common liquid,is a strong absorber in the far infrared range.Therefore,liquid water has historically been sworn off as a source for THz radiation.Recently,broadband THz wave generation from a flowing liquid target has been experimentally demonstrated through laser-induced microplasma.The liquid target as the THz source presents unique properties.Specifically,liquids have the comparable material density to that of solids,meaning that laser pulses over a certain area will interact with three orders more molecules than an equivalent cross-section of gases.In contrast with solid targets,the fluidity of liquid allows every laser pulse to interact with a fresh area on the target,meaning that material damage or degradation is not an issue with the high-repetition rate intense laser pulses.These make liquids very promising candidates for the investigation of high-energy-density plasma,as well as the possibility of being the next generation of THz sources.
基金Supported by the Ministry of Science and Higher Education of the Russian Federation,No.075-15-2022-301.
文摘BACKGROUND Lung damage in systemic juvenile arthritis(sJIA)is one of the contemporary topics in pediatric rheumatology.Several previous studies showed the severe course and fatal outcomes in some patients.The information about interstitial lung disease(ILD)in the sJIA is scarce and limited to a total of 100 cases.AIM To describe the features of sJIA patients with ILD in detail.METHODS In the present retrospective cohort study,information about 5 patients less than 18-years-old with sJIA and ILD were included.The diagnosis of sJIA was made according to the current 2004 and new provisional International League of Associations for Rheumatology criteria 2019.ILD was diagnosed with chest computed tomography with the exclusion of other possible reasons for concurrent lung involvement.Macrophage activation syndrome(MAS)was diagnosed with HLH-2004 and 2016 EULAR/ACR/PRINTO Classification Criteria and hScores were calculated during the lung involvement.RESULTS The onset age of sJIA ranged from 1 year to 10 years.The time interval before ILD ranged from 1 mo to 3 years.The disease course was characterized by the prevalence of the systemic features above articular involvement,intensive rash(100%),persistent and very active MAS(hScore range:194-220)with transaminitis(100%),and respiratory symptoms(100%).Only 3 patients(60%)developed a clubbing phenomenon.All patients(100%)had pleural effusion and 4 patients(80%)had pericardial effusion at the disease onset.Two patients(40%)developed pulmonary arterial hypertension.Infusion-related reactions to tocilizumab were observed in 3(60%)of the patients.One patient with trisomy 21 had a fatal disease course.Half of the remaining patients had sJIA remission and 2 patients had improvement.Lung disease improved in 3 patients(75%),but 1 of them had initial deterioration of lung involvement.One patient who has not achieved the sJIA remission had the progressed course of ILD.No cases of hyper-eosinophilia were noted.Four patients(80%)received canakinumab and one(20%)tocilizumab at the last
基金This work was supported by Russian Science Foundation(22-73-10069“Design and application of fl exible Metal organic frameworks for photonics devices,”the chemical part and structural analysis of developed MOFs)The of stability MOFs was conducted under the fi nancial support of the Ministry of Science and Higher Education of the Russian Federation as part of the World-Class Research Center program:Advanced Digital Technologies(contract No.075-15-2022-311 dated 20.04.2022)The authors thank the Engineering Centre of Saint Petersburg State Institute of Technology for PXRD analysis.
文摘Porous metal–organic frameworks(MOFs) have been recently discovered to be efficient catalysts for energy applications and green technologies. Here, we report on a scalable catalytic platform using Cu–based MOFs for electrocatalytic alkaline hydrogen evolution reaction. First, the solvothermal synthesis of Cu–BTC MOFs(BTC = 1,3,5–benzenetricarboxylate) at 85 ℃ and a 1:60 ligand–to–solvent ratio allowed for minimizing the chemical consumption. Second, the obtained platform demonstrated enhanced electrochemical performance compared with commercially available Cu–based MOFs, with a potential of –230 versus –232 eV, logarithm of the current density of –3.6 versus –4.2 cm2, and electrochemical surface area of 75 versus 25 cm2per cm2of geometric area, respectively. Morphological and Raman analyses also revealed that the high concentration of defects in the obtained submicron Cu–BTC MOFs can contribute to their improved catalytic performance. Thus, our findings pave the way to the low–cost synthesis of energy–efficient MOF–based catalysts for hydrogen production.
基金financial support from the Russian Science Foundation (grant No.20-72-10052)。
文摘We fit various color–magnitude diagrams(CMDs) of the high-latitude Galactic globular clusters NGC 5024(M53),NGC 5053,NGC 5272(M3),NGC 5466,and NGC 7099(M30) by isochrones from the Dartmouth Stellar Evolution Database and Bag of Stellar Tracks and Isochrones for α–enrichment [α/Fe] = +0.4.For the CMDs,we use data sets from Hubble Space Telescope,Gaia,and other sources utilizing,at least,25 photometric filters for each cluster.We obtain the following characteristics with their statistical uncertainties for NGC 5024,NGC 5053,NGC 5272,NGC 5466,and NGC 7099,respectively:metallicities [Fe/H] =-1.93 ± 0.02,-2.08 ± 0.03,-1.60 ± 0.02,-1.95 ± 0.02,and-2.07 ± 0.04 dex with their systematic uncertainty 0.1 dex;ages 13.00 ± 0.11,12.70 ± 0.11,11.63 ± 0.07,12.15 ± 0.11,and 12.80 ± 0.17 Gyr with their systematic uncertainty 0.8 Gyr;distances(systematic uncertainty added) 18.22 ± 0.06 ± 0.60,16.99 ± 0.06 ± 0.56,10.08 ± 0.04 ± 0.33,15.59 ±0.03 ± 0.51,and 8.29 ± 0.03 ± 0.27 kpc;reddenings E(B-V) = 0.023 ± 0.004,0.017 ± 0.004,0.023 ± 0.004,0.023 ± 0.003,and 0.045 ± 0.002 mag with their systematic uncertainty 0.01 mag;extinctions AV= 0.08 ± 0.01,0.06 ± 0.01,0.08 ± 0.01,0.08 ± 0.01,and 0.16 ± 0.01 mag with their systematic uncertainty 0.03 mag,which suggest the total Galactic extinction AV= 0.08 across the whole Galactic dust to extragalactic objects at the North Galactic Pole.The horizontal branch morphology difference of these clusters is explained by their different metallicity,age,mass-loss efficiency,and loss of low-mass members in the evolution of the core-collapse cluster NGC 7099 and loose clusters NGC 5053 and NGC 5466.
文摘Despite well-known limitations,mice remain useful as model animals to study tuberculosis(TB)pathogenesis,the basic immune response,the extent of lung pathology as well as efficacy of new drugs against Mycobacterium tuberculosis[1,2].There are four routes of tuberculosis infection in mice:aerosol generation and exposition,intravenous injection,intranasal administration,and subcutaneous administration[3].
基金supported by the Russian Science Foundation(Grant No.18-72-10137)。
文摘Modern trends in beam-driven radiation sources include the interaction of Cherenkov wakefields in open-ended circular waveguides with complicated dielectric linings, with a three-layer dielectric capillary recently proposed to reduce radiation divergence being a representative example [Opt. Lett. 45 5416(2020)]. We present a rigorous approach that allows for an analytical description of the electromagnetic processes that occur when the structure is excited by a single waveguide TM mode. In other words, the corresponding canonical waveguide diffraction problem is solved in a rigorous formulation. This is a continuation of our previous papers which considered simpler cases with a homogeneous or two-layer dielectric filling. Here we use the same analytical approach based on the Wiener–Hopf–Fock technique and deal with the more complicated case of a three-layer dielectric lining. Using the obtained rigorous solution, we discuss the possibility of manipulating the far-field radiation pattern using a third layer made of a low permittivity material.
基金National Natural Science Foundation of China,Grant/Award Numbers:12175050,12205067Fundamental Research Funds for the Central Universities,Grant/Award Number:HIT.OCEF.2022036。
文摘The Gatchina discharge phenomenon holds significant promise as a laboratory model for simulating ball lightning.However,crucial aspects concerning the plasma components of the resulting afterglow remain unresolved.Notably,the measurement of the electron density,a critical parameter,has not been fully achieved thus far.In this study,microwave diagnostics and video recording were employed during a pulsed Gatchina discharge,along with synchronous measurement of discharge current and voltage.Distinct antennas were positioned at different heights to enable separate diagnosis of the discharge and the ensuing long-lived afterglow.The findings revealed that during the active phase of the Gatchina discharge,the plasma density was substantial enough to cause reflection of an electromagnetic wave with a frequency of 20 GHz from this highly conductive object.In the afterglow,the signal experienced only a moderate weakening of 10–20 percent,facilitating the determination of the time dependence of average electron density during the afterglow's passage between the two antennas.These measurements verified the unusually slow plasma decay in the afterglow of the Gatchina discharge,suggesting the potential significance of chemi-ionisation processes involving long-lived(metastable)particles.
