Central Asia consists of the former Soviet Republics,Kazakhstan,Kyrgyz Republic,Tajikistan,Turkmenistan,and Uzbekistan.The region’s climate is continental,mostly semi-arid to arid.Agriculture is a significant part of...Central Asia consists of the former Soviet Republics,Kazakhstan,Kyrgyz Republic,Tajikistan,Turkmenistan,and Uzbekistan.The region’s climate is continental,mostly semi-arid to arid.Agriculture is a significant part of the region’s economy.By its nature of intensive water use,agriculture is extremely vulnerable to climate change.Population growth and irrigation development have significantly increased the demand for water in the region.Major climate change issues include melting glaciers and a shrinking snowpack,which are the foundation of the region’s water resources,and a changing precipitation regime.Most glaciers are located in Kyrgyzstan and Tajikistan,leading to transboundary water resource issues.Summer already has extremely high temperatures.Analyses indicate that Central Asia has been warming and precipitation might be increasing.The warming is expected to increase,but its spatial and temporal distribution depends upon specific global scenarios.Projections of future precipitation show significant uncertainties in type,amount,and distribution.Regional Hydroclimate Projects(RHPs)are an approach to studying these issues.Initial steps to develop an RHP began in 2021 with a widely distributed online survey about these climate issues.It was followed up with an online workshop and then,in 2023,an in-person workshop,held in Tashkent,Uzbekistan.Priorities for the Global Energy and Water Exchanges(GEWEX)project for the region include both observations and modeling,as well as development of better and additional precipitation observations,all of which are topics for the next workshop.A well-designed RHP should lead to reductions in critical climate uncertainties in policy-relevant timeframes that can influence decisions on necessary investments in climate adaptation.展开更多
Urinary leak is one of the most significant complications after partial nephrectomy.In case of persistent urine leaks,placement of a ureteral stent is effective but not always sufficient.This study included 5 patients...Urinary leak is one of the most significant complications after partial nephrectomy.In case of persistent urine leaks,placement of a ureteral stent is effective but not always sufficient.This study included 5 patients with persistent urinary leak after partial nephrectomy.The patients underwent flexible ureteroscopy wherein we identified the damaged calyx.Subsequently,we performed percutaneous puncture targeting the distal end of the endoscope at this calyx and installed a nephrostomy tube.Then,the endoscope was removed,and the ureter was drained with a stent.Ureteral stenting ensures elimination of urinary leak in most patients after partial nephrectomy.In patients with persistent urinary leak,retrograde endoscopic percutaneous drainage of the pelvicalyceal system is the method of choice because it allows for rapid and effective treatment of urinary fistulas.展开更多
The article presents the results of experimental studies on the gasification of mixtures of brown coal and polyethylene(up to 20 wt%fraction)in a laboratory reactor.The work aims to study the agglomeration process dur...The article presents the results of experimental studies on the gasification of mixtures of brown coal and polyethylene(up to 20 wt%fraction)in a laboratory reactor.The work aims to study the agglomeration process during the heating and oxidation of the mixtures.The measurement results(gas composition,pressure drop)provide indirect information on the dynamics of thermal decomposition and structural changes in the fuel bed.We have shown that the interaction between polyethylene and a coal surface leads to the formation of dense agglomerates,in which the molten polymer acts as a binder.Clinkers form as a result of interfacial interactions between components and filtration flow rearranging.The hydrogen/carbon ratio in the solid residue of coal-polyethylene co-gasification increases from 0.07–0.2 to 1.11,indicating the formation of stable hydrocarbon compounds on the carbon surface.The conducted research makes it possible to identify possible interactions between chemical reactions and transfer processes that lead to agglomeration in mixtures of coal with polyethylene.展开更多
Post-traumatic spinal cord remodeling includes both degenerating and regenerating processes,which affect the potency of the functional recovery after spinal cord injury(SCI).Gene therapy for spinal cord injury is prop...Post-traumatic spinal cord remodeling includes both degenerating and regenerating processes,which affect the potency of the functional recovery after spinal cord injury(SCI).Gene therapy for spinal cord injury is proposed as a promising therapeutic strategy to induce positive changes in remodeling of the affected neural tissue.In our previous studies for delivering the therapeutic genes at the site of spinal cord injury,we developed a new approach using an autologous leucoconcentrate transduced ex vivo with chimeric adenoviruses(Ad5/35)carrying recombinant cDNA.In the present study,the efficacy of the intravenous infusion of an autologous genetically-enriched leucoconcentrate simultaneously producing recombinant vascular endothelial growth factor(VEGF),glial cell line-derived neurotrophic factor(GDNF),and neural cell adhesion molecule(NCAM)was evaluated with regard to the molecular and cellular changes in remodeling of the spinal cord tissue at the site of damage in a model of mini-pigs with moderate spinal cord injury.Experimental animals were randomly divided into two groups of 4 pigs each:the therapeutic(infused with the leucoconcentrate simultaneously transduced with a combination of the three chimeric adenoviral vectors Ad5/35‐VEGF165,Ad5/35‐GDNF,and Ad5/35‐NCAM1)and control groups(infused with intact leucoconcentrate).The morphometric and immunofluorescence analysis of the spinal cord regeneration in the rostral and caudal segments according to the epicenter of the injury in the treated animals compared to the control mini-pigs showed:(1)higher sparing of the grey matter and increased survivability of the spinal cord cells(lower number of Caspase-3-positive cells and decreased expression of Hsp27);(2)recovery of synaptophysin expression;(3)prevention of astrogliosis(lower area of glial fibrillary acidic protein-positive astrocytes and ionized calcium binding adaptor molecule 1-positive microglial cells);(4)higher growth rates of regeneratingβIII-tubulin-positive axons accompanied by a higher number o展开更多
BACKGROUND:To assess the effectiveness of the telephone chest-compression-only cardiopulmonary resuscitation(CPR)guided by a pre-recorded instructional audio when compared with dispatcher-assisted resuscitation.METHOD...BACKGROUND:To assess the effectiveness of the telephone chest-compression-only cardiopulmonary resuscitation(CPR)guided by a pre-recorded instructional audio when compared with dispatcher-assisted resuscitation.METHODS:It was a prospective,blind,randomised controlled study involving 109 medical students without previous CPR training.In a standardized mannequin scenario,after the step of dispatcher-assisted cardiac arrest recognition,the participants performed compression-only resuscitation guided over the telephone by either:(1)the pre-recorded instructional audio(n=57);or(2)verbal dispatcher assistance(n=52).The simulation video records were reviewed to assess the CPR performance using a 13-item checklist.The interval from call reception to the first compression,total number and rate of compressions,total number and duration of pauses after the first compression were also recorded.RESULTS:There were no significant differences between the recording-assisted and dispatcher-assisted groups based on the overall performance score(5.6±2.2 vs.5.1±1.9,P>0.05)or individual criteria of the CPR performance checklist.The recording-assisted group demonstrated provided(170.2±48.0 vs.156.2±60.7).CONCLUSION:When provided by untrained persons in the simulated settings,the compression-only resuscitation guided by the pre-recorded instructional audio is no less efficient than dispatcher-assisted CPR.Future studies are warranted to further assess feasibility of using instructional audio aid as a potential alternative to dispatcher assistance.展开更多
Females of the ectoparasitoid Habrobracon hebetor attack and envenomate numerous host individuals during oviposition. The vectoring of the entomopathogenic fungus Beauveria bassiana during the adhesion stage by ectopa...Females of the ectoparasitoid Habrobracon hebetor attack and envenomate numerous host individuals during oviposition. The vectoring of the entomopathogenic fungus Beauveria bassiana during the adhesion stage by ectoparasitoid females among the wax moth larvae Galleria mellonella was explored under laboratory conditions. Vectoring occurred both from infected parasitoids to wax moth larvae and from infected to healthy wax moth larvae by parasitoids. The efficacy of vectoring in both cases was dose dependent. Parasitoid females were unable to recognize infected larvae in a labyrinth test. In addition, the presence of H. hebetor females significantly （1.5-13 fold） increased the mycoses level in clusters of G. mellonella, with 40% of the larvae infected with ftmgal conidia. Envenomation by H. hebetor increased conidia germination on the cuticles of the wax moth larvae by 4.4 fold. An enhanced germination rate （2 fold） was registered in the n- hexane epicuticular extract of envenomated larvae compared to that of healthy larvae. Both envenomation and mycoses enhanced the phenoloxidase （PO） activity in the integument of G. mellonella and, in contrast, decreased the encapsulation rate in hemolymphs. We hypothesize that changes in the integument property and inhibition of cellular immunity provide the highest infection efficacy of entomopathogenic fungi with H. hebetor.展开更多
Successful reproduction in mammals requires gamete development,fertilization,and early embryonic development.Defects in any of these processes can lead to infertility,recurrent miscarriages,and congenital defects.The ...Successful reproduction in mammals requires gamete development,fertilization,and early embryonic development.Defects in any of these processes can lead to infertility,recurrent miscarriages,and congenital defects.The clinical recognition of the genetic causes of female reproductive insufficiency using increasingly advanced genetic technologies poses a serious challenge for reproductive medicine in the 21st century.Herein,the current literature on genetic factors involved in reproductive losses was summarized.A literature search was conducted using Web of Science,MEDLINE,and PubMed databases for articles written in English on the genetic causes of women’s reproductive health disorders.Future implementation of whole-exome and wholegenome sequencing is expected to identify numerous genetic factors responsible for oocyte quality.Which will aid in increasing the likelihood of successful female reproductive function,improve the outcomes of assisted reproductive technologies,optimize treatment,and facilitate genetic diagnosis of patients.展开更多
Terahertz(THz)band(0.1–10 THz)is the next frontier for ultra-high-speed communication systems.Currently,most of communications research in this spectral range is focused on wireless systems,while waveguide/fiber-base...Terahertz(THz)band(0.1–10 THz)is the next frontier for ultra-high-speed communication systems.Currently,most of communications research in this spectral range is focused on wireless systems,while waveguide/fiber-based links have been less explored.Although free space communications have several advantages such as convenience in mobility for the end user,as well as easier multi-device interconnectivity in simple environments,fiber-based communications provide superior performance in certain short-range communication applications such as multi-device connectivity in complex geometrical environments(ex.,intra-vehicle connectivity)and secure communications with low probability of eavesdropping,as well as secure signal delivery to hard-to-reach or highly protected environments.In this work,we present an in-depth experimental and numerical study of the short-range THz communications links that use subwavelength dielectric fibers for information transmission and define the main challenges and trade-offs in the link implementation.Particularly,we use air or foam-cladded polypropylene-core subwavelength dielectric THz fibers of various diameters(0.57–1.75 mm)to study link performance as a function of the link length of up to∼10 m,and data bit rates of up to 6 Gbps at the carrier frequency of 128 GHz(2.34 mm wavelength).We find that depending on the fiber diameter,the quality of the transmitted signal is mostly limited either by the modal propagation loss or by the fiber velocity dispersion(GVD).An error-free transmission over 10 m is achieved for the bit rate of 4 Gbps using the fiber of smaller 0.57 mm diameter.Furthermore,since the fields of subwavelength fibers are weakly confined and extend deep into the air cladding,we study the modal field extent outside of the fiber core,as well as fiber bending loss.Finally,the power budget of the rod-in-air subwavelength THz fiber-based links is compared to that of free space communication links,and we demonstrate that fiber links offer an excellent solution for various sho展开更多
Metal hydride(MH)systems can be used for storage in stationary facilities of hydrogen with a high volume density at temperatures and pressures close to ambient ones.Recently,the possibility of using passive heating/co...Metal hydride(MH)systems can be used for storage in stationary facilities of hydrogen with a high volume density at temperatures and pressures close to ambient ones.Recently,the possibility of using passive heating/cooling systems or regenerative heat exchangers has been studied to improve the energy efficiency of MH systems for hydrogen storage without the need for forced circulation of a heating/cooling fluid.Natural convection of air may be used to passively remove/add heat as required for proper operation of a MH reactor.Under these conditions,the MH reactor can operate at a constant ambient air temperature and be driven by a difference in pressure between the source and the consumer of hydrogen.Since operation of MH systems with natural convective heating/cooling has not been systematically investigated as yet,a tubular MH reactor based on this principle is examined in this paper.Two-thirds of the internal volume ofø25.4×1 mm tube is occupied by a composition of LaNi5 and aluminium foam(one linear metre contains 1.1 kg of LaNi5 with a hydrogen capacity of 153 NL H2).Annular fins are used to increase heat transfer to air.Detailed and simplified mathematical models of the systems of this class are proposed and validated.It is shown that acceptable hydrogen charging/discharging rates in such systems are achieved with proper selection of fining characteristics.Charging from a hydrogen source at a pressure of 10 atm and an ambient air temperature of 10 to 30℃ takes 15 min.A reactor with a length of 1 m can desorb almost all stored hydrogen at a minimum outlet pressure of 0.45 bar to feed 30-300 W fuel cells.展开更多
Objective:This study aimed to develop expert fuzzy logic model to assist physicians in the prediction of postoperative complications of prostatic hyperplasia before surgery.Methods:A method for classification of surgi...Objective:This study aimed to develop expert fuzzy logic model to assist physicians in the prediction of postoperative complications of prostatic hyperplasia before surgery.Methods:A method for classification of surgical risks was developed.The effect of rotation of the current–voltage characteristics at biologically active points(acupuncture points)was used for the formation of classifier descriptors.The effect determined reversible and non-reversible changes in electrical resistance at acupuncture points with periodic exposure to a sawtooth probe current.Then,the developed method was tested on the prediction of the success of surgical treatment of benign prostatic hyperplasia.Results:Input descriptors were obtained from collected data including current-voltage characteristics of 5 acupuncture points and composed of 27 arrays feeding in the model.The maximum diagnostic sensitivity of the classifier for the success of a surgical operation in the control sample was 88%and for testing data set prediction accuracy was 97%.Conclusion:The use of tuples of current-voltage characteristic descriptors of acupuncture points in the classifiers could be used to predict the success of surgical treatment with satisfactory accuracy.The model can be a valuable tool to support physicians’diagnosis.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
In this paper,we review the existing approaches for vortex and vector beam shaping and generation in the terahertz frequency range.The particular focus of this review is on the possibility of homogeneous topological c...In this paper,we review the existing approaches for vortex and vector beam shaping and generation in the terahertz frequency range.The particular focus of this review is on the possibility of homogeneous topological charge formation in the ultra-wide spectral interval inherent to ultrashort terahertz pulses.We review the available materials and components,analyse proposed and potentially possible solutions for broadband terahertz vortex and vector beam shaping,compare all developed approaches,and put forward a unified concept for constructing passive shapers of such beams from the existing component base.展开更多
Optical cavities,resonant with vibrational or electronic transitions of material within the cavity,enable control of light-matter interaction.Previous studies have reported cavity-induced modifications of chemical rea...Optical cavities,resonant with vibrational or electronic transitions of material within the cavity,enable control of light-matter interaction.Previous studies have reported cavity-induced modifications of chemical reactivity,fluorescence,phase behavior,and charge transport.Here,we explore the effect of resonant cavity-phonon coupling on the transient photoconductivity in a hybrid organic-inorganic perovskite.To this end,we measure the ultrafast photoconductivity response of perovskite in a tunable Fabry–Pérot terahertz cavity,designed to be transparent for optical excitation.The terahertz-cavity field-phonon interaction causes apparent Rabi splitting between the perovskite phonon mode and the cavity mode.We explore whether the cavity-phonon interaction affects the material’s electron-phonon interaction by determining the charge-carrier mobility through photoconductivity.Despite the apparent hybridization of cavity and phonon modes,we show that the perovskite properties in both ground(phonon response)and excited(photoconductive response)states remain unaffected by the tunable light-matter interaction.Yet the response of the integral perovskite-terahertz optical cavity system depends critically on the interaction strength of the cavity with the phonon:the transient terahertz response to optical excitation can be increased up to threefold by tuning the cavity-perovskite interaction strength.These results enable tunable switches and frequency-controlled induced transparency devices.展开更多
This study examines how internal research and development(R&D),external knowledge acquisition,and R&D contracted with other companies interact in local and foreign-owned enterprises in post-communist economies...This study examines how internal research and development(R&D),external knowledge acquisition,and R&D contracted with other companies interact in local and foreign-owned enterprises in post-communist economies.A large sample of firm-level data from the Business Environment and Enterprise Performance Survey(BEEPS)across 26 postcommunist countries(including European Union(EU)members and non-EU states of Eastern Europe,Caucasian countries,and Central Asian countries)and country-level data from the Global Innovation Index and the International Property Rights Index were used.The findings show that enterprises with majority foreign ownership are relatively more likely to acquire external R&D.We demonstrate that the R&D behavior of enterprises with majority foreign ownership and local firms are interrelated,that is,we find a synergy effect.According to the results,decisions on internal R&D and the purchase of external knowledge for enterprises with majority foreign ownership are similar to those of local firms.However,enterprises with foreign ownership contract R&D with other companies more often if local firms conduct internal R&D.These results indicate the presence of knowledge spillover and cross-learning effects in both types of enterprises in postcommunist countries.Finally,we find that the national innovation environment is not significant for the R&D intensity of enterprises with majority foreign ownership,which suggests their high dependence on the parent structures of multinational enterprises.展开更多
In this paper,we demonstrate the capabilities of the terahertz pulse time-domain holography in visualisation,simulation,and assessment of broadband THz vortex beam formation dynamics upon its shaping by elements of be...In this paper,we demonstrate the capabilities of the terahertz pulse time-domain holography in visualisation,simulation,and assessment of broadband THz vortex beam formation dynamics upon its shaping by elements of beam converter,and further propagation and manipulation.By adding Jones matrix formalism to describe broadband optical elements,we highlight the differences in the spatio-spectral and spatio-temporal structure of the formed vortex and vector beams dependence on the modulator used and visualise their modal features.The influence of diffraction field structure from each element in the broadband vortex modulator is revealed in numerical simulation and the formed beams are analysed against the simplified Laguerre-Gaussian beam model.展开更多
For terahertz wave applications,tunable and rapid modulation is highly required.When studied by means of optical pump-terahertz probe spectroscopy,single-walled carbon nanotube(SWCNT)thin films demonstrated ultrafast ...For terahertz wave applications,tunable and rapid modulation is highly required.When studied by means of optical pump-terahertz probe spectroscopy,single-walled carbon nanotube(SWCNT)thin films demonstrated ultrafast carrier recombination lifetimes with a high relative change in the signal under optical excitation,making them promising candidates for high-speed modulators.Here,combination of SWCNT thin films and stretchable substrates facilitated studies of the SWCNT mechanical properties under strain and enabled the development of a new type of an optomechanical modulator.By applying a certain strain to the SWCNT films,the effective sheet conductance and therefore modulation depth can be fine-tuned to optimize the designed modulator.Modulators exhibited a photoconductivity change of approximately 2 times of magnitude under the strain because of the structural modification in the SWCNT network.Stretching was used to control the terahertz signal with a modulation depth of around 100%without strain and 65%at a high strain operation of 40%.The sensitivity of modulators to beam polarization is also shown,which might also come in handy for the design of a stretchable polarizer.Our results give a fundamental grounding for the design of high-sensitivity stretchable devices based on SWCNT films.展开更多
The article presents an original method for the automatic assessment of the quality of event-related potentials(ERPs),based on the calculation of the coefficientε,which describes the compliance of recorded ERPs with ...The article presents an original method for the automatic assessment of the quality of event-related potentials(ERPs),based on the calculation of the coefficientε,which describes the compliance of recorded ERPs with some statistically significant parameters.This method was used to analyze the neuropsychological EEG monitoring of patients suffering from migraines.The frequency of migraine attacks was correlated with the spatial distribution of the coefficientsε,calculated for EEG channels.More than 15 migraine attacks per month was accompanied by an increase in calculated values in the occipital region.Patients with infrequent migraines exhibited maximum quality in the frontal areas.The automatic analysis of spatial maps of the coefficientεdemonstrated a statistically significant difference between the two analyzed groups with different means of migraine attack numbers per month.展开更多
基金The National Research University Tashkent Institute of Irrigation and Agricultural Mechanization Engineers of Uzbekistan hosted and provided financial support for the in-person workshop in May of 2023
文摘Central Asia consists of the former Soviet Republics,Kazakhstan,Kyrgyz Republic,Tajikistan,Turkmenistan,and Uzbekistan.The region’s climate is continental,mostly semi-arid to arid.Agriculture is a significant part of the region’s economy.By its nature of intensive water use,agriculture is extremely vulnerable to climate change.Population growth and irrigation development have significantly increased the demand for water in the region.Major climate change issues include melting glaciers and a shrinking snowpack,which are the foundation of the region’s water resources,and a changing precipitation regime.Most glaciers are located in Kyrgyzstan and Tajikistan,leading to transboundary water resource issues.Summer already has extremely high temperatures.Analyses indicate that Central Asia has been warming and precipitation might be increasing.The warming is expected to increase,but its spatial and temporal distribution depends upon specific global scenarios.Projections of future precipitation show significant uncertainties in type,amount,and distribution.Regional Hydroclimate Projects(RHPs)are an approach to studying these issues.Initial steps to develop an RHP began in 2021 with a widely distributed online survey about these climate issues.It was followed up with an online workshop and then,in 2023,an in-person workshop,held in Tashkent,Uzbekistan.Priorities for the Global Energy and Water Exchanges(GEWEX)project for the region include both observations and modeling,as well as development of better and additional precipitation observations,all of which are topics for the next workshop.A well-designed RHP should lead to reductions in critical climate uncertainties in policy-relevant timeframes that can influence decisions on necessary investments in climate adaptation.
文摘Urinary leak is one of the most significant complications after partial nephrectomy.In case of persistent urine leaks,placement of a ureteral stent is effective but not always sufficient.This study included 5 patients with persistent urinary leak after partial nephrectomy.The patients underwent flexible ureteroscopy wherein we identified the damaged calyx.Subsequently,we performed percutaneous puncture targeting the distal end of the endoscope at this calyx and installed a nephrostomy tube.Then,the endoscope was removed,and the ureter was drained with a stent.Ureteral stenting ensures elimination of urinary leak in most patients after partial nephrectomy.In patients with persistent urinary leak,retrograde endoscopic percutaneous drainage of the pelvicalyceal system is the method of choice because it allows for rapid and effective treatment of urinary fistulas.
文摘The article presents the results of experimental studies on the gasification of mixtures of brown coal and polyethylene(up to 20 wt%fraction)in a laboratory reactor.The work aims to study the agglomeration process during the heating and oxidation of the mixtures.The measurement results(gas composition,pressure drop)provide indirect information on the dynamics of thermal decomposition and structural changes in the fuel bed.We have shown that the interaction between polyethylene and a coal surface leads to the formation of dense agglomerates,in which the molten polymer acts as a binder.Clinkers form as a result of interfacial interactions between components and filtration flow rearranging.The hydrogen/carbon ratio in the solid residue of coal-polyethylene co-gasification increases from 0.07–0.2 to 1.11,indicating the formation of stable hydrocarbon compounds on the carbon surface.The conducted research makes it possible to identify possible interactions between chemical reactions and transfer processes that lead to agglomeration in mixtures of coal with polyethylene.
基金supported by a grant from the Russian Science Foundation,No. 16-15-00010 (to RRI)funded by government assignment for FRC Kazan Scientific Center of RAS
文摘Post-traumatic spinal cord remodeling includes both degenerating and regenerating processes,which affect the potency of the functional recovery after spinal cord injury(SCI).Gene therapy for spinal cord injury is proposed as a promising therapeutic strategy to induce positive changes in remodeling of the affected neural tissue.In our previous studies for delivering the therapeutic genes at the site of spinal cord injury,we developed a new approach using an autologous leucoconcentrate transduced ex vivo with chimeric adenoviruses(Ad5/35)carrying recombinant cDNA.In the present study,the efficacy of the intravenous infusion of an autologous genetically-enriched leucoconcentrate simultaneously producing recombinant vascular endothelial growth factor(VEGF),glial cell line-derived neurotrophic factor(GDNF),and neural cell adhesion molecule(NCAM)was evaluated with regard to the molecular and cellular changes in remodeling of the spinal cord tissue at the site of damage in a model of mini-pigs with moderate spinal cord injury.Experimental animals were randomly divided into two groups of 4 pigs each:the therapeutic(infused with the leucoconcentrate simultaneously transduced with a combination of the three chimeric adenoviral vectors Ad5/35‐VEGF165,Ad5/35‐GDNF,and Ad5/35‐NCAM1)and control groups(infused with intact leucoconcentrate).The morphometric and immunofluorescence analysis of the spinal cord regeneration in the rostral and caudal segments according to the epicenter of the injury in the treated animals compared to the control mini-pigs showed:(1)higher sparing of the grey matter and increased survivability of the spinal cord cells(lower number of Caspase-3-positive cells and decreased expression of Hsp27);(2)recovery of synaptophysin expression;(3)prevention of astrogliosis(lower area of glial fibrillary acidic protein-positive astrocytes and ionized calcium binding adaptor molecule 1-positive microglial cells);(4)higher growth rates of regeneratingβIII-tubulin-positive axons accompanied by a higher number o
文摘BACKGROUND:To assess the effectiveness of the telephone chest-compression-only cardiopulmonary resuscitation(CPR)guided by a pre-recorded instructional audio when compared with dispatcher-assisted resuscitation.METHODS:It was a prospective,blind,randomised controlled study involving 109 medical students without previous CPR training.In a standardized mannequin scenario,after the step of dispatcher-assisted cardiac arrest recognition,the participants performed compression-only resuscitation guided over the telephone by either:(1)the pre-recorded instructional audio(n=57);or(2)verbal dispatcher assistance(n=52).The simulation video records were reviewed to assess the CPR performance using a 13-item checklist.The interval from call reception to the first compression,total number and rate of compressions,total number and duration of pauses after the first compression were also recorded.RESULTS:There were no significant differences between the recording-assisted and dispatcher-assisted groups based on the overall performance score(5.6±2.2 vs.5.1±1.9,P>0.05)or individual criteria of the CPR performance checklist.The recording-assisted group demonstrated provided(170.2±48.0 vs.156.2±60.7).CONCLUSION:When provided by untrained persons in the simulated settings,the compression-only resuscitation guided by the pre-recorded instructional audio is no less efficient than dispatcher-assisted CPR.Future studies are warranted to further assess feasibility of using instructional audio aid as a potential alternative to dispatcher assistance.
文摘Females of the ectoparasitoid Habrobracon hebetor attack and envenomate numerous host individuals during oviposition. The vectoring of the entomopathogenic fungus Beauveria bassiana during the adhesion stage by ectoparasitoid females among the wax moth larvae Galleria mellonella was explored under laboratory conditions. Vectoring occurred both from infected parasitoids to wax moth larvae and from infected to healthy wax moth larvae by parasitoids. The efficacy of vectoring in both cases was dose dependent. Parasitoid females were unable to recognize infected larvae in a labyrinth test. In addition, the presence of H. hebetor females significantly （1.5-13 fold） increased the mycoses level in clusters of G. mellonella, with 40% of the larvae infected with ftmgal conidia. Envenomation by H. hebetor increased conidia germination on the cuticles of the wax moth larvae by 4.4 fold. An enhanced germination rate （2 fold） was registered in the n- hexane epicuticular extract of envenomated larvae compared to that of healthy larvae. Both envenomation and mycoses enhanced the phenoloxidase （PO） activity in the integument of G. mellonella and, in contrast, decreased the encapsulation rate in hemolymphs. We hypothesize that changes in the integument property and inhibition of cellular immunity provide the highest infection efficacy of entomopathogenic fungi with H. hebetor.
基金supported by Project No.15.BRK.21.008 Multicenter Research Bioresource Collection“Human Reproductive Health”(Agreement No.075-15-2021-1058 dated September 28,2021)funded by the Ministry of Science and Higher Education of the Russian Federation.
文摘Successful reproduction in mammals requires gamete development,fertilization,and early embryonic development.Defects in any of these processes can lead to infertility,recurrent miscarriages,and congenital defects.The clinical recognition of the genetic causes of female reproductive insufficiency using increasingly advanced genetic technologies poses a serious challenge for reproductive medicine in the 21st century.Herein,the current literature on genetic factors involved in reproductive losses was summarized.A literature search was conducted using Web of Science,MEDLINE,and PubMed databases for articles written in English on the genetic causes of women’s reproductive health disorders.Future implementation of whole-exome and wholegenome sequencing is expected to identify numerous genetic factors responsible for oocyte quality.Which will aid in increasing the likelihood of successful female reproductive function,improve the outcomes of assisted reproductive technologies,optimize treatment,and facilitate genetic diagnosis of patients.
基金The Canada Research Chairs I program and the Canada Foundation for Innovation grant(Project No.34633)in Ubiquitous THz Photonics of Prof.Maksim Skorobogatiy.
文摘Terahertz(THz)band(0.1–10 THz)is the next frontier for ultra-high-speed communication systems.Currently,most of communications research in this spectral range is focused on wireless systems,while waveguide/fiber-based links have been less explored.Although free space communications have several advantages such as convenience in mobility for the end user,as well as easier multi-device interconnectivity in simple environments,fiber-based communications provide superior performance in certain short-range communication applications such as multi-device connectivity in complex geometrical environments(ex.,intra-vehicle connectivity)and secure communications with low probability of eavesdropping,as well as secure signal delivery to hard-to-reach or highly protected environments.In this work,we present an in-depth experimental and numerical study of the short-range THz communications links that use subwavelength dielectric fibers for information transmission and define the main challenges and trade-offs in the link implementation.Particularly,we use air or foam-cladded polypropylene-core subwavelength dielectric THz fibers of various diameters(0.57–1.75 mm)to study link performance as a function of the link length of up to∼10 m,and data bit rates of up to 6 Gbps at the carrier frequency of 128 GHz(2.34 mm wavelength).We find that depending on the fiber diameter,the quality of the transmitted signal is mostly limited either by the modal propagation loss or by the fiber velocity dispersion(GVD).An error-free transmission over 10 m is achieved for the bit rate of 4 Gbps using the fiber of smaller 0.57 mm diameter.Furthermore,since the fields of subwavelength fibers are weakly confined and extend deep into the air cladding,we study the modal field extent outside of the fiber core,as well as fiber bending loss.Finally,the power budget of the rod-in-air subwavelength THz fiber-based links is compared to that of free space communication links,and we demonstrate that fiber links offer an excellent solution for various sho
文摘Metal hydride(MH)systems can be used for storage in stationary facilities of hydrogen with a high volume density at temperatures and pressures close to ambient ones.Recently,the possibility of using passive heating/cooling systems or regenerative heat exchangers has been studied to improve the energy efficiency of MH systems for hydrogen storage without the need for forced circulation of a heating/cooling fluid.Natural convection of air may be used to passively remove/add heat as required for proper operation of a MH reactor.Under these conditions,the MH reactor can operate at a constant ambient air temperature and be driven by a difference in pressure between the source and the consumer of hydrogen.Since operation of MH systems with natural convective heating/cooling has not been systematically investigated as yet,a tubular MH reactor based on this principle is examined in this paper.Two-thirds of the internal volume ofø25.4×1 mm tube is occupied by a composition of LaNi5 and aluminium foam(one linear metre contains 1.1 kg of LaNi5 with a hydrogen capacity of 153 NL H2).Annular fins are used to increase heat transfer to air.Detailed and simplified mathematical models of the systems of this class are proposed and validated.It is shown that acceptable hydrogen charging/discharging rates in such systems are achieved with proper selection of fining characteristics.Charging from a hydrogen source at a pressure of 10 atm and an ambient air temperature of 10 to 30℃ takes 15 min.A reactor with a length of 1 m can desorb almost all stored hydrogen at a minimum outlet pressure of 0.45 bar to feed 30-300 W fuel cells.
基金supported by the Russian Foundation for Basic Research(RFBR),project number 19–38-90116。
文摘Objective:This study aimed to develop expert fuzzy logic model to assist physicians in the prediction of postoperative complications of prostatic hyperplasia before surgery.Methods:A method for classification of surgical risks was developed.The effect of rotation of the current–voltage characteristics at biologically active points(acupuncture points)was used for the formation of classifier descriptors.The effect determined reversible and non-reversible changes in electrical resistance at acupuncture points with periodic exposure to a sawtooth probe current.Then,the developed method was tested on the prediction of the success of surgical treatment of benign prostatic hyperplasia.Results:Input descriptors were obtained from collected data including current-voltage characteristics of 5 acupuncture points and composed of 27 arrays feeding in the model.The maximum diagnostic sensitivity of the classifier for the success of a surgical operation in the control sample was 88%and for testing data set prediction accuracy was 97%.Conclusion:The use of tuples of current-voltage characteristic descriptors of acupuncture points in the classifiers could be used to predict the success of surgical treatment with satisfactory accuracy.The model can be a valuable tool to support physicians’diagnosis.
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.
文摘In this paper,we review the existing approaches for vortex and vector beam shaping and generation in the terahertz frequency range.The particular focus of this review is on the possibility of homogeneous topological charge formation in the ultra-wide spectral interval inherent to ultrashort terahertz pulses.We review the available materials and components,analyse proposed and potentially possible solutions for broadband terahertz vortex and vector beam shaping,compare all developed approaches,and put forward a unified concept for constructing passive shapers of such beams from the existing component base.
基金This work has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant No 811284.
文摘Optical cavities,resonant with vibrational or electronic transitions of material within the cavity,enable control of light-matter interaction.Previous studies have reported cavity-induced modifications of chemical reactivity,fluorescence,phase behavior,and charge transport.Here,we explore the effect of resonant cavity-phonon coupling on the transient photoconductivity in a hybrid organic-inorganic perovskite.To this end,we measure the ultrafast photoconductivity response of perovskite in a tunable Fabry–Pérot terahertz cavity,designed to be transparent for optical excitation.The terahertz-cavity field-phonon interaction causes apparent Rabi splitting between the perovskite phonon mode and the cavity mode.We explore whether the cavity-phonon interaction affects the material’s electron-phonon interaction by determining the charge-carrier mobility through photoconductivity.Despite the apparent hybridization of cavity and phonon modes,we show that the perovskite properties in both ground(phonon response)and excited(photoconductive response)states remain unaffected by the tunable light-matter interaction.Yet the response of the integral perovskite-terahertz optical cavity system depends critically on the interaction strength of the cavity with the phonon:the transient terahertz response to optical excitation can be increased up to threefold by tuning the cavity-perovskite interaction strength.These results enable tunable switches and frequency-controlled induced transparency devices.
基金This article is the output of a research project implemented as part of the Basic Research Program at the National Research University Higher School of Economics(HSE University).
文摘This study examines how internal research and development(R&D),external knowledge acquisition,and R&D contracted with other companies interact in local and foreign-owned enterprises in post-communist economies.A large sample of firm-level data from the Business Environment and Enterprise Performance Survey(BEEPS)across 26 postcommunist countries(including European Union(EU)members and non-EU states of Eastern Europe,Caucasian countries,and Central Asian countries)and country-level data from the Global Innovation Index and the International Property Rights Index were used.The findings show that enterprises with majority foreign ownership are relatively more likely to acquire external R&D.We demonstrate that the R&D behavior of enterprises with majority foreign ownership and local firms are interrelated,that is,we find a synergy effect.According to the results,decisions on internal R&D and the purchase of external knowledge for enterprises with majority foreign ownership are similar to those of local firms.However,enterprises with foreign ownership contract R&D with other companies more often if local firms conduct internal R&D.These results indicate the presence of knowledge spillover and cross-learning effects in both types of enterprises in postcommunist countries.Finally,we find that the national innovation environment is not significant for the R&D intensity of enterprises with majority foreign ownership,which suggests their high dependence on the parent structures of multinational enterprises.
基金Russian Science Foundation,Project No 19-72-10147The work of A.G.is supported by EPSRC Grant No.EP/S018395/1。
文摘In this paper,we demonstrate the capabilities of the terahertz pulse time-domain holography in visualisation,simulation,and assessment of broadband THz vortex beam formation dynamics upon its shaping by elements of beam converter,and further propagation and manipulation.By adding Jones matrix formalism to describe broadband optical elements,we highlight the differences in the spatio-spectral and spatio-temporal structure of the formed vortex and vector beams dependence on the modulator used and visualise their modal features.The influence of diffraction field structure from each element in the broadband vortex modulator is revealed in numerical simulation and the formed beams are analysed against the simplified Laguerre-Gaussian beam model.
基金M.G.B.and M.I.P.acknowledge Russian Science Foundation(RSF)project no.21-79-10097(experimental OPTP measurements)Ministry of Science and Higher Education of the Russian Federation no.0714-2020-0002(anisotropy factor measurements for SWCNT films)+1 种基金Moreover,M.G.B.acknowledges RSF project no.22-72-10033(investigation of the stretchable modulators efficiency)B.P.G.and A.G.N.acknowledge RSF project no.21-72-20050(sample preparation).
文摘For terahertz wave applications,tunable and rapid modulation is highly required.When studied by means of optical pump-terahertz probe spectroscopy,single-walled carbon nanotube(SWCNT)thin films demonstrated ultrafast carrier recombination lifetimes with a high relative change in the signal under optical excitation,making them promising candidates for high-speed modulators.Here,combination of SWCNT thin films and stretchable substrates facilitated studies of the SWCNT mechanical properties under strain and enabled the development of a new type of an optomechanical modulator.By applying a certain strain to the SWCNT films,the effective sheet conductance and therefore modulation depth can be fine-tuned to optimize the designed modulator.Modulators exhibited a photoconductivity change of approximately 2 times of magnitude under the strain because of the structural modification in the SWCNT network.Stretching was used to control the terahertz signal with a modulation depth of around 100%without strain and 65%at a high strain operation of 40%.The sensitivity of modulators to beam polarization is also shown,which might also come in handy for the design of a stretchable polarizer.Our results give a fundamental grounding for the design of high-sensitivity stretchable devices based on SWCNT films.
基金partially supported by the Russian Federation Government Grant No.075-15-2022-1094(clinical data processing)supported by the Ministry of Science and Higher Education of the Russian Federation in the framework of the state assignment(FSRR-2020-0003)partially supported by the Russian Foundation for Basic Research(20-02-00752).
文摘The article presents an original method for the automatic assessment of the quality of event-related potentials(ERPs),based on the calculation of the coefficientε,which describes the compliance of recorded ERPs with some statistically significant parameters.This method was used to analyze the neuropsychological EEG monitoring of patients suffering from migraines.The frequency of migraine attacks was correlated with the spatial distribution of the coefficientsε,calculated for EEG channels.More than 15 migraine attacks per month was accompanied by an increase in calculated values in the occipital region.Patients with infrequent migraines exhibited maximum quality in the frontal areas.The automatic analysis of spatial maps of the coefficientεdemonstrated a statistically significant difference between the two analyzed groups with different means of migraine attack numbers per month.
