The MTF is extended to case of attenuating incident wave by introducing an attenuation coefficient. The reflection coefficients of this modified MTF and MTF are evaluated and compared when an attenuating wave impinges...The MTF is extended to case of attenuating incident wave by introducing an attenuation coefficient. The reflection coefficients of this modified MTF and MTF are evaluated and compared when an attenuating wave impinges on the boundary, and the results demonstrate that MTF can be used to absorb slightly attenuating waves and the modified MTF is more capable of absorbing heavily attenuating waves than MTF. The accuracy of modified MTF is also tested by numerical examples of fluid saturated porous media.展开更多
Objective: To observe and assess the efficacy enhancing and toxicity attenuating effect of Nuzhen Yangyin Granule (NYG) to the anti-parkinsonism (paralysis agitans) therapy with medopa and ar-tane. Methods: Adopting t...Objective: To observe and assess the efficacy enhancing and toxicity attenuating effect of Nuzhen Yangyin Granule (NYG) to the anti-parkinsonism (paralysis agitans) therapy with medopa and ar-tane. Methods: Adopting the randomized double-blinded method, the effect of adding NYG to 30 patients with Parkinsonism in the treated group,展开更多
Skeletal metastasis in carcinoma cervix occurs in about 0.8-23%of cases.These lesions are usually radiographically lytic.Very few cases of metastases to the skull have been identified,about 5 cases to the best of our ...Skeletal metastasis in carcinoma cervix occurs in about 0.8-23%of cases.These lesions are usually radiographically lytic.Very few cases of metastases to the skull have been identified,about 5 cases to the best of our knowledge.We present a case of adenosquamous cell carcinoma of cervix with fat attenuating skull metastases in a 38-year-old lady that is not reported till date.The lesion was lytic,expansile and with negative attenuation of-15 to-30 Hounsfield units corresponding to fat.Metastases must be included in the differentials of scalp lesions.A history of recent onset of swelling and associated lytic areas in calvarium on contrast enhanced computed tomography with multiplicity can give a clue to metastatic nature of disease.展开更多
In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using at...In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using attenuated total reflectance Fourier-transform infrared spectroscopy(ATR-FTIR),the molecular configurations of surface carboxyl groups(COOH),free carboxyl(COOH_(f))and hydrogen-bonded carboxyl(COOH_(HB),were directly correlated with the polar component of surface energy(γ^(s,p)).By decomposing theγ^(s,p)values of the PAA thin films as a sum of the contributions of COOH_(f)and COOH_(H B),the intrinsic polar component of surface energy of COOH_(H B)(γ_(H B)^(s,p*))was quantified for the first time as 8.34 mN/m,significantly lower than that of COOH_(f)(γ_(f)^(s,p*)=34 mN/m).This result highlights that hydrogen bonding markedly reduces theγ^(s,p),providing a rational explanation for the relatively large water contact angle observed on PAA thin films.Furthermore,it establishes a thermodynamic basis for estimating the fraction of surface COOH_(H B)groups(f H B)from wettability measurements.Further extension of the model to carboxyl-terminated self-assembled monolayers(COOH-SAMs)revealed that surface COOH density(ΣCOOH)critically regulates wetting behavior:whenΣCOOH ranges from 4.30 to 5.25 nm^(-2),COOH groups predominantly exist in a free state and facilitate effective hydration layers,thereby promoting superhydrophilicity.Overall,this study not only establishes a unified thermodynamic framework linking surface COOH configurations to macroscopic wettability,but also validates its universality by extending it to COOH-SAMs systems,thereby providing a unified theoretical framework for the controllable design of hydrophilicity in various COOH-functionalized surfaces.展开更多
Novel MEMS torsion-mirror actuators with monolithically integrated fiber self-holding structures are fabricated, and investigated experimentally and theoretically. Their electromechanical and optical characteristics a...Novel MEMS torsion-mirror actuators with monolithically integrated fiber self-holding structures are fabricated, and investigated experimentally and theoretically. Their electromechanical and optical characteristics are acceptable for optical switching or attenuating applications.展开更多
Excessive blasting-induced vibration during drilling-and-blasting excavation of deep tunnels can trigger geological hazards and compromise the stability of both the rock mass and support structures.This study focused ...Excessive blasting-induced vibration during drilling-and-blasting excavation of deep tunnels can trigger geological hazards and compromise the stability of both the rock mass and support structures.This study focused on the deep double-line Sejila Mountain tunnel to systematically analyze the spatial response of blasting-induced vibration and to develop a prediction model through field tests and numerical simulations.The results revealed that the presence of a cross passage significantly altered propagation paths and the spatial distribution of blasting-induced vibration velocity.The peak particle velocity(PPV)at the cross-passage corner was amplified by approximately 1.92 times due to wave reflection and geometric focusing.Blasting-induced vibration waves attenuated non-uniformly across the tunnel cross-section,where PPV on the blast-face side was 1.54–6.56 times higher than that on the opposite side.We propose an improved PPV attenuation model that accounts for the propagation path effect.This model significantly improved fitting accuracy and resolved anomalous parameter(k and a)estimates in traditional equations,thereby improving prediction reliability.Furthermore,based on the observed spatial distribution of blasting-induced vibration,optimal monitoring point placement and targeted vibration control measures for tunnel blasting were discussed.These findings provide a scientific basis for designing blasting schemes and vibration mitigation strategies in deep tunnels.展开更多
Local resonant acoustic metamaterials have broad applications in sound insulation,yet their single-configuration designs often exhibit limited and discontinuous bandgap widths,hindering full-frequency noise attenuatio...Local resonant acoustic metamaterials have broad applications in sound insulation,yet their single-configuration designs often exhibit limited and discontinuous bandgap widths,hindering full-frequency noise attenuation across the human auditory range.This study presents a double-phase fidget-spinner-shaped acoustic metamaterial(DFAM),specifically designed to achieve an ultra-broad,low-frequency continuous bandgap by means of synergistic structural optimization,enabling effective and robust control of audible noise.Based on Bloch's theorem and the finite element method,the dispersion relation of the DFAM structure is calculated and verified by the transmission loss curves.The propagation characteristics of sound waves within the structure are further analyzed for noise frequencies that fall within the passband.The influence of the geometric and physical parameters on the bandgap is investigated,and the corresponding transmission loss in the propagation direction is further calculated.A hybrid collaborative design strategy,leveraging multi-parameter optimization and bandgap complementarity,is developed to construct a metastructure with continuous bandgap coverage from 20 Hz to 1000 Hz.The resulting metastructure demonstrates exceptional broadband noise attenuation,achieving a total bandgap width of 876.3 Hz(87.63% of the target range)with the transmission loss up to-762.78 d B in a three-periodic arrangement.The simulation and experimental results for the transmission loss of the DFAM metastructure show strong agreement in the low-frequency range.This work provides a novel framework for designing ultra-wide low-frequency continuous bandgap metastructures,offering significant potential for noise mitigation in complex environments.展开更多
Artificial intelligence(AI)is revolutionizing medical imaging,particularly in chronic liver diseases assessment.AI technologies,including machine learning and deep learning,are increasingly integrated with multiparame...Artificial intelligence(AI)is revolutionizing medical imaging,particularly in chronic liver diseases assessment.AI technologies,including machine learning and deep learning,are increasingly integrated with multiparametric ultrasound(US)techniques to provide more accurate,objective,and non-invasive evaluations of liver fibrosis and steatosis.Analyzing large datasets from US images,AI enhances diagnostic precision,enabling better quantification of liver stiffness and fat content,which are essential for diagnosing and staging liver fibrosis and steatosis.Combining advanced US modalities,such as elastography and doppler imaging with AI,has demonstrated improved sensitivity in identifying different stages of liver disease and distinguishing various degrees of steatotic liver.These advancements also contribute to greater reproducibility and reduced operator dependency,addressing some of the limitations of traditional methods.The clinical implications of AI in liver disease are vast,ranging from early detection to predicting disease progression and evaluating treatment response.Despite these promising developments,challenges such as the need for large-scale datasets,algorithm transparency,and clinical validation remain.The aim of this review is to explore the current applications and future potential of AI in liver fibrosis and steatosis assessment using multiparametric US,highlighting the technological advances and clinical relevance of this emerging field.展开更多
Residents living near drill-and-blast tunnels often experience disturbances from blasting operations.This motivates us to investigate the characteristics of airblasts and resulting noise through on-site monitoring at ...Residents living near drill-and-blast tunnels often experience disturbances from blasting operations.This motivates us to investigate the characteristics of airblasts and resulting noise through on-site monitoring at three tunnels.The research focuses on both the temporal evolution and spatial propagation of airblasts.Temporal analysis,including peak overpressure(POp),positive duration(PD),and Fourier main frequency(MF),emphasizes the relationship between airblast characteristics,blasting delays,and rock grade.It shows that airblast bandwidths are typically in the range of 3e200 Hz,with noise levels exceeding 130 dB,which is comparable to jet engines and rocket launch.Spatial propagation analysis reveals the impact of tunnel space on airblast propagation.Although POp and PD typically decrease with distance inside the tunnel,wave superposition can cause increased overpressure and prolonged durations at far-field distances(above 60 m kg^(-1/3)).Outside the tunnel,sound radiation was influenced by azimuth and was basically determined by sound power d an often-overlooked factor.To address the anisotropic propagation of airblasts,a predictive model was proposed for external noise levels,considering variables like distance,azimuth angle,initial sound power,and wave expansion.Validated by tests,this model successfully unifies data from three studies,helping to explain and predict airblast disturbances near tunnels.展开更多
Although traditional gamma-gamma density(GGD)logging technology is widely utilized,its potential environmental risks have prompted the development of more environmentally friendly neutron-gamma density(NGD)logging tec...Although traditional gamma-gamma density(GGD)logging technology is widely utilized,its potential environmental risks have prompted the development of more environmentally friendly neutron-gamma density(NGD)logging technology.However,NGD measurements are influenced by both neutron and gamma radiations.In the logging environment,variations in the formation composition indicate different elemental compositions,which affect the neutron-gamma reaction cross-sections and gamma generation.Compared to traditional gamma sources such as Cs-137,these changes significantly affect the generation and transport of neutron-induced inelastic gamma rays and hinder accurate measurements.To address this,a novel method is proposed that incorporates the mass attenuation coefficient function to account for the effects of various lithologies and pore contents on gamma-ray attenuation,thereby achieving more accurate density measurements by clarifying the transport processes of inelastic gamma rays with varying energies and spatial distributions in varied logging environments.The proposed method avoids the complex correction of neutron transport and is verified through Monte Carlo simulations for its applicability across various lithologies and pore contents,demonstrating absolute density errors that are less than 0.02 g/cm^(3)in clean formations and indicating good accuracy.This study clarifies the NGD mechanism and provides theoretical guidance for the application of NGD logging methods.Further studies will be conducted on extreme environmental conditions and tool calibration.展开更多
To understand sound propagation and beam formation, the physical properties of soft tissues from the biosonar system of odontocetes should be explored. Based on the acoustic impedance distributions of biosonar systems...To understand sound propagation and beam formation, the physical properties of soft tissues from the biosonar system of odontocetes should be explored. Based on the acoustic impedance distributions of biosonar systems, these processes have been examined via numerical simulations. In this study, the images of a short-beaked common dolphin(Delphinus delphis) were obtained via computed tomography. Then, the dolphin was dissected to extract tissue samples for additional examination. In addition to the speed of sound and density measurements, the acoustic attenuation coefficients of the biosonar system in the forehead were tested. The results revealed that the inner layer of the forehead was characterized using low sound speed, low density, and high attenuation. Acoustic fields and beam patterns were then evaluated by setting acoustic attenuation coefficients at different levels. Sounds propagating along the low-attenuation path had a lesser reduction in amplitude. Beam directivities in near and far fields suggested that changes in attenuation distribution would cause beam patterns to shift. These results indicated the complexity of a dolphin’s sonar emission system and helped improve our understanding of sound energy attenuation via studies on the forehead of odontocetes.展开更多
This study proposes a numerically efficient technique for computing the far-field scattered by a spherical target placed near the seabed.The bottom is supposed to be a homogeneous liquid attenuating half-space.The tra...This study proposes a numerically efficient technique for computing the far-field scattered by a spherical target placed near the seabed.The bottom is supposed to be a homogeneous liquid attenuating half-space.The transmitter and receiver are situated at different points of a homogeneous water half-space.The distances between the transmitter,receiver,and object of interest are assumed to be much larger than the acoustic wavelength in water.The scattered far-field is ascertained using Hackman and Sammelmann’s general approach.The arising scattering coefficients of a sphere are assessed using the steepest descent approach.The branch cut contribution is also considered.The obtained formulas for the form-function can be used for acoustically rigid or soft scatterers,as well as elastic targets or spherical elastic shells.Numerical simulations are conducted for an acoustically rigid sphere.Asymptotic expressions for the scattering coefficients allow a decrease in the number of summands in the formula for the target strength and a significant reduction in computational time.展开更多
In this paper,the failure caused by HRAM loads which were generated by high-speed projectile penetration,and protection technology of the fluid-filled structure were explored.A bubble was preset on the projectile traj...In this paper,the failure caused by HRAM loads which were generated by high-speed projectile penetration,and protection technology of the fluid-filled structure were explored.A bubble was preset on the projectile trajectory in a fluid-filled structure.Based on the reflection and transmission phenomena of pressure waves at the gas-liquid interface and the compressibility characteristics of gases,a numerical analysis was conducted on the influence of preset bubble on projectile penetration and structural failure characteristics.The results indicate that the secondary water-entry impact phenomenon occurs when a preset bubble exists on the projectile trajectory,leading to the secondary water entry impact loads.The rarefaction waves reflected on the surface of the preset bubble cause the attenuation ratio of the initial impact pressure peak to reach 68.8%and the total specific impulse attenuation ratio to reach 48.6%.Furthermore,the larger the bubble,the faster the projectile,and the more obvious the attenuation effect.Moreover,due to the compressibility of the bubble,the global deformation attenuation ratio of the front and rear walls can reach over 80%.However,the larger the bubble size,the faster the projectile velocity,the smaller the local deformation attenuation effect of the rear wall,and the more severe the failure at the perforation of the rear wall.展开更多
BACKGROUND Hepatic steatosis,characterized by fat accumulation in hepatocytes,can result from metabolic dysfunction-associated steatotic liver disease(MASLD),infections,alcoholism,chemotherapy,and toxins.MASLD is diag...BACKGROUND Hepatic steatosis,characterized by fat accumulation in hepatocytes,can result from metabolic dysfunction-associated steatotic liver disease(MASLD),infections,alcoholism,chemotherapy,and toxins.MASLD is diagnosed via imaging or biopsy with metabolic criteria and may progress to metabolic dysfunction–asso-ciated steatohepatitis,potentially leading to fibrosis,cirrhosis,or cancer.The coexistence of hepatic steatosis with chronic hepatitis B(CHB)is mainly related to metabolic factors and increases mortality and cancer risks.As a noninvasive method,attenuation imaging(ATI)shows promise in quantifying liver fat,demonstrating strong correlation with liver biopsy.AIM To investigate the disparity of ATI for assessing biopsy-based hepatic steatosis in CHB patients and MASLD patients.METHODS The study enrolled 249 patients who underwent both ATI and liver biopsy,including 78 with CHB and 171 with MASLD.Hepatic steatosis was classified into grades S0 to S3 according to the proportion of fat cells present.Liver fibrosis was staged from 0 to 4 according to the meta-analysis of histological data in viral hepatitis scoring system.The diagnostic performance of attenuation coefficient(AC)values across different groups was compared for each grade of steatosis.Factors associated with the AC values were determined through linear regression analysis.A multivariate logistic regression model was established to predict≥S2 within the MASLD group.RESULTS In both the CHB and the MASLD groups,AC values increased significantly with higher steatosis grade(P<0.001).In the CHB group,the areas under the curve(AUCs)of AC for predicting steatosis grades≥S1,≥S2 and S3 were 0.918,0.960 and 0.987,respectively.In contrast,the MASLD group showed AUCs of 0.836,0.774,and 0.688 for the same steatosis grades.The diagnostic performance of AC for detecting≥S2 and S3 indicated significant differences between the two groups(both P<0.001).Multivariate linear regression analysis identified body mass index,trigly-cerides,and steatosis grade as significant factors for AC.When the steatosis grade is≥S2,it can progress to more serious liver conditions.A clinical model integrating blood biochemical parameters and AC was developed in the MASLD group to enhance the prediction of≥S2,achieving an AUC of 0.848.CONCLUSION The AC could effectively discriminate the degree of steatosis in both the CHB and MASLD groups.In the MASLD group,when combined with blood biochemical parameters,AC exhibited better predictive ability for moderate to severe steatosis.展开更多
The present technical paper outlines the details of the controlled blasting techniques used to optimize blasting pattern for excavation of hard rock near the Bhira Earthen Dam in Maharashtra,India.In this connection,a...The present technical paper outlines the details of the controlled blasting techniques used to optimize blasting pattern for excavation of hard rock near the Bhira Earthen Dam in Maharashtra,India.In this connection,a series of experimental blasts were conducted by adjusting various blast design parameters at project site.The safe charge weight per delay was kept between 0.125 and 0.375 kg.The outcomes of these experimental blasts were analyzed to recommend optimized blasting patterns and methods for the overall excavation process during actual blasting operations.Blast design parameters,including the maximum quantity of explosive per delay,hole depth,burden and spacing between holes were optimized by using a site-specific attenuation equation,taking into account the proximity of the dam and tunnel from the blasting area.Peak particle velocity(PPV)level of 10 mm/s and 50 mm/s respectively were adopted as the safe vibration level for ensuring safety of the Bhira Earthen Dam and the nearby tunnel from the adverse effects of blast vibrations by analyzing the dominant frequency of ground vibrations observed and also by reviewing various international standards.Frequency of the ground vibrations observed on the dam and tunnel from majority of the blasts was found to be more than 10 Hz and 50 Hz respectively.During the entire period of blasting,the blast vibrations were recorded to be far lower than the safe vibration level set for these structures.Maximum Vibration level of about 0.8 mm/s and 35 mm/s were observed on dam and tunnel respectively which are far lower than the safe vibration level adopted for these structures.Hence,the entire excavation work was completed successfully and safely,without endangering the safety of dam or tunnel.展开更多
Myocardial perfusion imaging(MPI),which uses single-photon emission computed tomography(SPECT),is a well-known estimating tool for medical diagnosis,employing the classification of images to show situations in coronar...Myocardial perfusion imaging(MPI),which uses single-photon emission computed tomography(SPECT),is a well-known estimating tool for medical diagnosis,employing the classification of images to show situations in coronary artery disease(CAD).The automatic classification of SPECT images for different techniques has achieved near-optimal accuracy when using convolutional neural networks(CNNs).This paper uses a SPECT classification framework with three steps:1)Image denoising,2)Attenuation correction,and 3)Image classification.Image denoising is done by a U-Net architecture that ensures effective image denoising.Attenuation correction is implemented by a convolution neural network model that can remove the attenuation that affects the feature extraction process of classification.Finally,a novel multi-scale diluted convolution(MSDC)network is proposed.It merges the features extracted in different scales and makes the model learn the features more efficiently.Three scales of filters with size 3×3 are used to extract features.All three steps are compared with state-of-the-art methods.The proposed denoising architecture ensures a high-quality image with the highest peak signal-to-noise ratio(PSNR)value of 39.7.The proposed classification method is compared with the five different CNN models,and the proposed method ensures better classification with an accuracy of 96%,precision of 87%,sensitivity of 87%,specificity of 89%,and F1-score of 87%.To demonstrate the importance of preprocessing,the classification model was analyzed without denoising and attenuation correction.展开更多
BACKGROUND Inadequately controlled hypertension often leads to an increased cardiovascular death rate in type 2 diabetes mellitus(T2DM).It remains unclear whether systolic blood pressure(SBP)status of hypertension is ...BACKGROUND Inadequately controlled hypertension often leads to an increased cardiovascular death rate in type 2 diabetes mellitus(T2DM).It remains unclear whether systolic blood pressure(SBP)status of hypertension is related to coronary inflammation and plaques in T2DM.AIM To evaluate whether SBP variability(SBPV)and levels of hypertension are related to coronary inflammation and plaques in T2DM patients using coronary computed tomography angiography(CCTA).METHODS This retrospective study involved 881 T2DM patients with CCTA images,including 668 hypertension and 213 normotension patients.Hypertension patients were subgroup based on SBP status:(1)SBPV:Low(<8.96 mmHg)and high(≥8.96 mmHg)groups;and(2)SBP levels:Controlled(<140 mmHg)and uncontrolled(≥140 mmHg)groups.Pericoronary adipose tissue(PCAT)attenuation,high-risk plaques(HRPs)and obstructive stenosis(OS)were evaluated by CCTA.Propensity score matching was utilized to compare these CCTA findings for these groups.The impact of SBPV and SBP levels of hypertension on these CCTA findings in T2DM patients were evaluated by multivariate logistic regression and multivariable linear regression.RESULTS PCAT attenuation of the left anterior descending artery(LAD),any low attenuation plaque(LAP),any spotty calcification(SC),any positive remodeling(PR),and OS had significant differences between the hypertension group and the normotension group,as well as between the high SBPV or uncontrolled SBP group and the low SBPV or controlled SBP group(all P<0.05).Hypertension was independently positively correlated with LADPCAT attenuation(β=1.815,P=0.010),LAP(OR=1.612,P=0.019),SC(OR=1.665,P=0.013),PR(OR=1.549,P=0.033),and OS(OR=1.928,P=0.036)in all T2DM patients.Additionally,high SBPV and uncontrolled SBP were independently positively correlated with LAD-PCAT attenuation(high SBPV:β=1.673,P=0.048;uncontrolled SBP:β=2.370,P=0.004)and PR(high SBPV:OR=1.903,P=0.048;uncontrolled SBP:OR=2.230,P=0.013)in T2DM patients with hypertension.CONCLUSION Inadequately controlled hypertension,including high SBPV and/or uncontrolled SBP levels,may be related to increased coronary artery inflammation,HRPs,and OS in T2DM,leading to increased cardiovascular risk.Achieving both low SBPV and controlled SBP levels simultaneously,especially in individuals with T2DM and hypertension,warrants clinical attention.展开更多
Ultrasound computed tomography(USCT)is a noninvasive biomedical imaging modality that offers insights into acoustic properties such as the sound speed(SS)and acoustic attenuation(AA)of the human body,enhancing diagnos...Ultrasound computed tomography(USCT)is a noninvasive biomedical imaging modality that offers insights into acoustic properties such as the sound speed(SS)and acoustic attenuation(AA)of the human body,enhancing diagnostic accuracy and therapy planning.Full waveform inversion(FWI)is a promising USCT image reconstruction method that optimizes the parameter fields of a wave propagation model via gradient-based optimization.However,twodimensional FWI methods are limited by their inability to account for three-dimensional wave propagation in the elevation direction,resulting in image artifacts.To address this problem,we propose a three-dimensional time-domain full waveform inversion algorithm to reconstruct the SS and AA distributions on the basis of a fractional Laplacian wave equation,adjoint field formulation,and gradient descent optimization.Validated by two sets of simulations,the proposed algorithm has potential for generating high-resolution and quantitative SS and AA distributions.This approach holds promise for clinical USCT applications,assisting early disease detection,precise abnormality localization,and optimized treatment planning,thus contributing to better healthcare outcomes.展开更多
The attenuation and anisotropy characteristics of real earth media give rise to amplitude loss and phase dispersion during seismic wave propagation.To address these effects on seismic imaging,viscoacoustic anisotropic...The attenuation and anisotropy characteristics of real earth media give rise to amplitude loss and phase dispersion during seismic wave propagation.To address these effects on seismic imaging,viscoacoustic anisotropic wave equations expressed by the fractional Laplacian have been derived.However,the huge computational expense associated with multiple Fast Fourier transforms for solving these wave equations makes them unsuitable for industrial applications,especially in three dimensions.Therefore,we first derived a cost-effective pure-viscoacoustic wave equation expressed by the memory-variable in tilted transversely isotropic(TTI)media,based on the standard linear solid model.The newly derived wave equation featuring decoupled amplitude dissipation and phase dispersion terms,can be easily solved using the finite-difference method(FDM).Computational efficiency analyses demonstrate that wavefields simulated by our newly derived wave equation are more efficient compared to the previous pure-viscoacoustic TTI wave equations.The decoupling characteristics of the phase dispersion and amplitude dissipation of the proposed wave equation are illustrated in numerical tests.Additionally,we extend the newly derived wave equation to implement Q-compensated reverse time migration(RTM)in attenuating TTI media.Synthetic examples and field data test demonstrate that the proposed Qcompensated TTI RTM effectively migrate the effects of anisotropy and attenuation,providing highquality imaging results.展开更多
Imagine a future where a single vaccine could protect you from a multitude of influenza strains,offering broad immunity with minimal risk.This vision is now closer to reality,thanks to a recent study that harnesses th...Imagine a future where a single vaccine could protect you from a multitude of influenza strains,offering broad immunity with minimal risk.This vision is now closer to reality,thanks to a recent study that harnesses the power of cellular proteins to create a new generation of live attenuated vaccines that outsmart flu’s relentless mutations.展开更多
基金China Joint Seismological Science Foundation (95-07-442).
文摘The MTF is extended to case of attenuating incident wave by introducing an attenuation coefficient. The reflection coefficients of this modified MTF and MTF are evaluated and compared when an attenuating wave impinges on the boundary, and the results demonstrate that MTF can be used to absorb slightly attenuating waves and the modified MTF is more capable of absorbing heavily attenuating waves than MTF. The accuracy of modified MTF is also tested by numerical examples of fluid saturated porous media.
文摘Objective: To observe and assess the efficacy enhancing and toxicity attenuating effect of Nuzhen Yangyin Granule (NYG) to the anti-parkinsonism (paralysis agitans) therapy with medopa and ar-tane. Methods: Adopting the randomized double-blinded method, the effect of adding NYG to 30 patients with Parkinsonism in the treated group,
文摘Skeletal metastasis in carcinoma cervix occurs in about 0.8-23%of cases.These lesions are usually radiographically lytic.Very few cases of metastases to the skull have been identified,about 5 cases to the best of our knowledge.We present a case of adenosquamous cell carcinoma of cervix with fat attenuating skull metastases in a 38-year-old lady that is not reported till date.The lesion was lytic,expansile and with negative attenuation of-15 to-30 Hounsfield units corresponding to fat.Metastases must be included in the differentials of scalp lesions.A history of recent onset of swelling and associated lytic areas in calvarium on contrast enhanced computed tomography with multiplicity can give a clue to metastatic nature of disease.
文摘In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using attenuated total reflectance Fourier-transform infrared spectroscopy(ATR-FTIR),the molecular configurations of surface carboxyl groups(COOH),free carboxyl(COOH_(f))and hydrogen-bonded carboxyl(COOH_(HB),were directly correlated with the polar component of surface energy(γ^(s,p)).By decomposing theγ^(s,p)values of the PAA thin films as a sum of the contributions of COOH_(f)and COOH_(H B),the intrinsic polar component of surface energy of COOH_(H B)(γ_(H B)^(s,p*))was quantified for the first time as 8.34 mN/m,significantly lower than that of COOH_(f)(γ_(f)^(s,p*)=34 mN/m).This result highlights that hydrogen bonding markedly reduces theγ^(s,p),providing a rational explanation for the relatively large water contact angle observed on PAA thin films.Furthermore,it establishes a thermodynamic basis for estimating the fraction of surface COOH_(H B)groups(f H B)from wettability measurements.Further extension of the model to carboxyl-terminated self-assembled monolayers(COOH-SAMs)revealed that surface COOH density(ΣCOOH)critically regulates wetting behavior:whenΣCOOH ranges from 4.30 to 5.25 nm^(-2),COOH groups predominantly exist in a free state and facilitate effective hydration layers,thereby promoting superhydrophilicity.Overall,this study not only establishes a unified thermodynamic framework linking surface COOH configurations to macroscopic wettability,but also validates its universality by extending it to COOH-SAMs systems,thereby providing a unified theoretical framework for the controllable design of hydrophilicity in various COOH-functionalized surfaces.
文摘Novel MEMS torsion-mirror actuators with monolithically integrated fiber self-holding structures are fabricated, and investigated experimentally and theoretically. Their electromechanical and optical characteristics are acceptable for optical switching or attenuating applications.
基金financially supported by the National Natural Science Foundation of China(Nos.42577209 and U22A20239)the Key R&D Program of Hunan Province(No.2024WK2004)the Key Technologies for Accurate Diagnosis and Intelligent Prevention and Control of Slope Hazards in Open pit Mines,181 Major R&D projects of Metallurgical Corporation of China Ltd。
文摘Excessive blasting-induced vibration during drilling-and-blasting excavation of deep tunnels can trigger geological hazards and compromise the stability of both the rock mass and support structures.This study focused on the deep double-line Sejila Mountain tunnel to systematically analyze the spatial response of blasting-induced vibration and to develop a prediction model through field tests and numerical simulations.The results revealed that the presence of a cross passage significantly altered propagation paths and the spatial distribution of blasting-induced vibration velocity.The peak particle velocity(PPV)at the cross-passage corner was amplified by approximately 1.92 times due to wave reflection and geometric focusing.Blasting-induced vibration waves attenuated non-uniformly across the tunnel cross-section,where PPV on the blast-face side was 1.54–6.56 times higher than that on the opposite side.We propose an improved PPV attenuation model that accounts for the propagation path effect.This model significantly improved fitting accuracy and resolved anomalous parameter(k and a)estimates in traditional equations,thereby improving prediction reliability.Furthermore,based on the observed spatial distribution of blasting-induced vibration,optimal monitoring point placement and targeted vibration control measures for tunnel blasting were discussed.These findings provide a scientific basis for designing blasting schemes and vibration mitigation strategies in deep tunnels.
基金Project supported by the National Natural Science Foundation of China(No.12572020)the Key Project of Natural Science Foundation of Hebei Province of China(No.A2023210064)。
文摘Local resonant acoustic metamaterials have broad applications in sound insulation,yet their single-configuration designs often exhibit limited and discontinuous bandgap widths,hindering full-frequency noise attenuation across the human auditory range.This study presents a double-phase fidget-spinner-shaped acoustic metamaterial(DFAM),specifically designed to achieve an ultra-broad,low-frequency continuous bandgap by means of synergistic structural optimization,enabling effective and robust control of audible noise.Based on Bloch's theorem and the finite element method,the dispersion relation of the DFAM structure is calculated and verified by the transmission loss curves.The propagation characteristics of sound waves within the structure are further analyzed for noise frequencies that fall within the passband.The influence of the geometric and physical parameters on the bandgap is investigated,and the corresponding transmission loss in the propagation direction is further calculated.A hybrid collaborative design strategy,leveraging multi-parameter optimization and bandgap complementarity,is developed to construct a metastructure with continuous bandgap coverage from 20 Hz to 1000 Hz.The resulting metastructure demonstrates exceptional broadband noise attenuation,achieving a total bandgap width of 876.3 Hz(87.63% of the target range)with the transmission loss up to-762.78 d B in a three-periodic arrangement.The simulation and experimental results for the transmission loss of the DFAM metastructure show strong agreement in the low-frequency range.This work provides a novel framework for designing ultra-wide low-frequency continuous bandgap metastructures,offering significant potential for noise mitigation in complex environments.
文摘Artificial intelligence(AI)is revolutionizing medical imaging,particularly in chronic liver diseases assessment.AI technologies,including machine learning and deep learning,are increasingly integrated with multiparametric ultrasound(US)techniques to provide more accurate,objective,and non-invasive evaluations of liver fibrosis and steatosis.Analyzing large datasets from US images,AI enhances diagnostic precision,enabling better quantification of liver stiffness and fat content,which are essential for diagnosing and staging liver fibrosis and steatosis.Combining advanced US modalities,such as elastography and doppler imaging with AI,has demonstrated improved sensitivity in identifying different stages of liver disease and distinguishing various degrees of steatotic liver.These advancements also contribute to greater reproducibility and reduced operator dependency,addressing some of the limitations of traditional methods.The clinical implications of AI in liver disease are vast,ranging from early detection to predicting disease progression and evaluating treatment response.Despite these promising developments,challenges such as the need for large-scale datasets,algorithm transparency,and clinical validation remain.The aim of this review is to explore the current applications and future potential of AI in liver fibrosis and steatosis assessment using multiparametric US,highlighting the technological advances and clinical relevance of this emerging field.
基金supported by the Shenzhen Stability Support Plan(Grant No.20231122095154003)National Natural Science Foundation of China(Grant Nos.51978671 and 52422807).
文摘Residents living near drill-and-blast tunnels often experience disturbances from blasting operations.This motivates us to investigate the characteristics of airblasts and resulting noise through on-site monitoring at three tunnels.The research focuses on both the temporal evolution and spatial propagation of airblasts.Temporal analysis,including peak overpressure(POp),positive duration(PD),and Fourier main frequency(MF),emphasizes the relationship between airblast characteristics,blasting delays,and rock grade.It shows that airblast bandwidths are typically in the range of 3e200 Hz,with noise levels exceeding 130 dB,which is comparable to jet engines and rocket launch.Spatial propagation analysis reveals the impact of tunnel space on airblast propagation.Although POp and PD typically decrease with distance inside the tunnel,wave superposition can cause increased overpressure and prolonged durations at far-field distances(above 60 m kg^(-1/3)).Outside the tunnel,sound radiation was influenced by azimuth and was basically determined by sound power d an often-overlooked factor.To address the anisotropic propagation of airblasts,a predictive model was proposed for external noise levels,considering variables like distance,azimuth angle,initial sound power,and wave expansion.Validated by tests,this model successfully unifies data from three studies,helping to explain and predict airblast disturbances near tunnels.
基金supported by the National Natural Science Foundation of China(U23B20151 and 52171253).
文摘Although traditional gamma-gamma density(GGD)logging technology is widely utilized,its potential environmental risks have prompted the development of more environmentally friendly neutron-gamma density(NGD)logging technology.However,NGD measurements are influenced by both neutron and gamma radiations.In the logging environment,variations in the formation composition indicate different elemental compositions,which affect the neutron-gamma reaction cross-sections and gamma generation.Compared to traditional gamma sources such as Cs-137,these changes significantly affect the generation and transport of neutron-induced inelastic gamma rays and hinder accurate measurements.To address this,a novel method is proposed that incorporates the mass attenuation coefficient function to account for the effects of various lithologies and pore contents on gamma-ray attenuation,thereby achieving more accurate density measurements by clarifying the transport processes of inelastic gamma rays with varying energies and spatial distributions in varied logging environments.The proposed method avoids the complex correction of neutron transport and is verified through Monte Carlo simulations for its applicability across various lithologies and pore contents,demonstrating absolute density errors that are less than 0.02 g/cm^(3)in clean formations and indicating good accuracy.This study clarifies the NGD mechanism and provides theoretical guidance for the application of NGD logging methods.Further studies will be conducted on extreme environmental conditions and tool calibration.
基金supported by the National Key Research and Development Program of China (Grant Nos. 2018YFC1407504, and 2018YFC1407505)National Natural Science Foundation of China (Grant No. 12074323)+3 种基金Special Fund for Marine and Fishery Development of Xiamen (Grant No.20CZB015HJ01)Water Conservancy Science and Technology Innovation Project of Guangdong (Grant No. 2020-16)China Postdoctoral Science Foundation (Grant No. 2020M682086)China National Postdoctoral Program for Innovative Talents (Grant No. BX2021168)。
文摘To understand sound propagation and beam formation, the physical properties of soft tissues from the biosonar system of odontocetes should be explored. Based on the acoustic impedance distributions of biosonar systems, these processes have been examined via numerical simulations. In this study, the images of a short-beaked common dolphin(Delphinus delphis) were obtained via computed tomography. Then, the dolphin was dissected to extract tissue samples for additional examination. In addition to the speed of sound and density measurements, the acoustic attenuation coefficients of the biosonar system in the forehead were tested. The results revealed that the inner layer of the forehead was characterized using low sound speed, low density, and high attenuation. Acoustic fields and beam patterns were then evaluated by setting acoustic attenuation coefficients at different levels. Sounds propagating along the low-attenuation path had a lesser reduction in amplitude. Beam directivities in near and far fields suggested that changes in attenuation distribution would cause beam patterns to shift. These results indicated the complexity of a dolphin’s sonar emission system and helped improve our understanding of sound energy attenuation via studies on the forehead of odontocetes.
基金Supported by the Ministry of Science and Higher Education of the Russian Federation as a part of World-class Research Center Program:Advanced Digital Technologies(contract No.075-15-2022-312 dated 20 April 2022).
文摘This study proposes a numerically efficient technique for computing the far-field scattered by a spherical target placed near the seabed.The bottom is supposed to be a homogeneous liquid attenuating half-space.The transmitter and receiver are situated at different points of a homogeneous water half-space.The distances between the transmitter,receiver,and object of interest are assumed to be much larger than the acoustic wavelength in water.The scattered far-field is ascertained using Hackman and Sammelmann’s general approach.The arising scattering coefficients of a sphere are assessed using the steepest descent approach.The branch cut contribution is also considered.The obtained formulas for the form-function can be used for acoustically rigid or soft scatterers,as well as elastic targets or spherical elastic shells.Numerical simulations are conducted for an acoustically rigid sphere.Asymptotic expressions for the scattering coefficients allow a decrease in the number of summands in the formula for the target strength and a significant reduction in computational time.
文摘In this paper,the failure caused by HRAM loads which were generated by high-speed projectile penetration,and protection technology of the fluid-filled structure were explored.A bubble was preset on the projectile trajectory in a fluid-filled structure.Based on the reflection and transmission phenomena of pressure waves at the gas-liquid interface and the compressibility characteristics of gases,a numerical analysis was conducted on the influence of preset bubble on projectile penetration and structural failure characteristics.The results indicate that the secondary water-entry impact phenomenon occurs when a preset bubble exists on the projectile trajectory,leading to the secondary water entry impact loads.The rarefaction waves reflected on the surface of the preset bubble cause the attenuation ratio of the initial impact pressure peak to reach 68.8%and the total specific impulse attenuation ratio to reach 48.6%.Furthermore,the larger the bubble,the faster the projectile,and the more obvious the attenuation effect.Moreover,due to the compressibility of the bubble,the global deformation attenuation ratio of the front and rear walls can reach over 80%.However,the larger the bubble size,the faster the projectile velocity,the smaller the local deformation attenuation effect of the rear wall,and the more severe the failure at the perforation of the rear wall.
基金Supported by the National Natural Science Foundation of China,No.82202185and Shanghai Science and Technology Development Foundation,No.22Y11911500.
文摘BACKGROUND Hepatic steatosis,characterized by fat accumulation in hepatocytes,can result from metabolic dysfunction-associated steatotic liver disease(MASLD),infections,alcoholism,chemotherapy,and toxins.MASLD is diagnosed via imaging or biopsy with metabolic criteria and may progress to metabolic dysfunction–asso-ciated steatohepatitis,potentially leading to fibrosis,cirrhosis,or cancer.The coexistence of hepatic steatosis with chronic hepatitis B(CHB)is mainly related to metabolic factors and increases mortality and cancer risks.As a noninvasive method,attenuation imaging(ATI)shows promise in quantifying liver fat,demonstrating strong correlation with liver biopsy.AIM To investigate the disparity of ATI for assessing biopsy-based hepatic steatosis in CHB patients and MASLD patients.METHODS The study enrolled 249 patients who underwent both ATI and liver biopsy,including 78 with CHB and 171 with MASLD.Hepatic steatosis was classified into grades S0 to S3 according to the proportion of fat cells present.Liver fibrosis was staged from 0 to 4 according to the meta-analysis of histological data in viral hepatitis scoring system.The diagnostic performance of attenuation coefficient(AC)values across different groups was compared for each grade of steatosis.Factors associated with the AC values were determined through linear regression analysis.A multivariate logistic regression model was established to predict≥S2 within the MASLD group.RESULTS In both the CHB and the MASLD groups,AC values increased significantly with higher steatosis grade(P<0.001).In the CHB group,the areas under the curve(AUCs)of AC for predicting steatosis grades≥S1,≥S2 and S3 were 0.918,0.960 and 0.987,respectively.In contrast,the MASLD group showed AUCs of 0.836,0.774,and 0.688 for the same steatosis grades.The diagnostic performance of AC for detecting≥S2 and S3 indicated significant differences between the two groups(both P<0.001).Multivariate linear regression analysis identified body mass index,trigly-cerides,and steatosis grade as significant factors for AC.When the steatosis grade is≥S2,it can progress to more serious liver conditions.A clinical model integrating blood biochemical parameters and AC was developed in the MASLD group to enhance the prediction of≥S2,achieving an AUC of 0.848.CONCLUSION The AC could effectively discriminate the degree of steatosis in both the CHB and MASLD groups.In the MASLD group,when combined with blood biochemical parameters,AC exhibited better predictive ability for moderate to severe steatosis.
文摘The present technical paper outlines the details of the controlled blasting techniques used to optimize blasting pattern for excavation of hard rock near the Bhira Earthen Dam in Maharashtra,India.In this connection,a series of experimental blasts were conducted by adjusting various blast design parameters at project site.The safe charge weight per delay was kept between 0.125 and 0.375 kg.The outcomes of these experimental blasts were analyzed to recommend optimized blasting patterns and methods for the overall excavation process during actual blasting operations.Blast design parameters,including the maximum quantity of explosive per delay,hole depth,burden and spacing between holes were optimized by using a site-specific attenuation equation,taking into account the proximity of the dam and tunnel from the blasting area.Peak particle velocity(PPV)level of 10 mm/s and 50 mm/s respectively were adopted as the safe vibration level for ensuring safety of the Bhira Earthen Dam and the nearby tunnel from the adverse effects of blast vibrations by analyzing the dominant frequency of ground vibrations observed and also by reviewing various international standards.Frequency of the ground vibrations observed on the dam and tunnel from majority of the blasts was found to be more than 10 Hz and 50 Hz respectively.During the entire period of blasting,the blast vibrations were recorded to be far lower than the safe vibration level set for these structures.Maximum Vibration level of about 0.8 mm/s and 35 mm/s were observed on dam and tunnel respectively which are far lower than the safe vibration level adopted for these structures.Hence,the entire excavation work was completed successfully and safely,without endangering the safety of dam or tunnel.
基金the Research Grant of Kwangwoon University in 2024.
文摘Myocardial perfusion imaging(MPI),which uses single-photon emission computed tomography(SPECT),is a well-known estimating tool for medical diagnosis,employing the classification of images to show situations in coronary artery disease(CAD).The automatic classification of SPECT images for different techniques has achieved near-optimal accuracy when using convolutional neural networks(CNNs).This paper uses a SPECT classification framework with three steps:1)Image denoising,2)Attenuation correction,and 3)Image classification.Image denoising is done by a U-Net architecture that ensures effective image denoising.Attenuation correction is implemented by a convolution neural network model that can remove the attenuation that affects the feature extraction process of classification.Finally,a novel multi-scale diluted convolution(MSDC)network is proposed.It merges the features extracted in different scales and makes the model learn the features more efficiently.Three scales of filters with size 3×3 are used to extract features.All three steps are compared with state-of-the-art methods.The proposed denoising architecture ensures a high-quality image with the highest peak signal-to-noise ratio(PSNR)value of 39.7.The proposed classification method is compared with the five different CNN models,and the proposed method ensures better classification with an accuracy of 96%,precision of 87%,sensitivity of 87%,specificity of 89%,and F1-score of 87%.To demonstrate the importance of preprocessing,the classification model was analyzed without denoising and attenuation correction.
基金Supported by Natural Science Foundation of Hubei Province,No.2023AFB848.
文摘BACKGROUND Inadequately controlled hypertension often leads to an increased cardiovascular death rate in type 2 diabetes mellitus(T2DM).It remains unclear whether systolic blood pressure(SBP)status of hypertension is related to coronary inflammation and plaques in T2DM.AIM To evaluate whether SBP variability(SBPV)and levels of hypertension are related to coronary inflammation and plaques in T2DM patients using coronary computed tomography angiography(CCTA).METHODS This retrospective study involved 881 T2DM patients with CCTA images,including 668 hypertension and 213 normotension patients.Hypertension patients were subgroup based on SBP status:(1)SBPV:Low(<8.96 mmHg)and high(≥8.96 mmHg)groups;and(2)SBP levels:Controlled(<140 mmHg)and uncontrolled(≥140 mmHg)groups.Pericoronary adipose tissue(PCAT)attenuation,high-risk plaques(HRPs)and obstructive stenosis(OS)were evaluated by CCTA.Propensity score matching was utilized to compare these CCTA findings for these groups.The impact of SBPV and SBP levels of hypertension on these CCTA findings in T2DM patients were evaluated by multivariate logistic regression and multivariable linear regression.RESULTS PCAT attenuation of the left anterior descending artery(LAD),any low attenuation plaque(LAP),any spotty calcification(SC),any positive remodeling(PR),and OS had significant differences between the hypertension group and the normotension group,as well as between the high SBPV or uncontrolled SBP group and the low SBPV or controlled SBP group(all P<0.05).Hypertension was independently positively correlated with LADPCAT attenuation(β=1.815,P=0.010),LAP(OR=1.612,P=0.019),SC(OR=1.665,P=0.013),PR(OR=1.549,P=0.033),and OS(OR=1.928,P=0.036)in all T2DM patients.Additionally,high SBPV and uncontrolled SBP were independently positively correlated with LAD-PCAT attenuation(high SBPV:β=1.673,P=0.048;uncontrolled SBP:β=2.370,P=0.004)and PR(high SBPV:OR=1.903,P=0.048;uncontrolled SBP:OR=2.230,P=0.013)in T2DM patients with hypertension.CONCLUSION Inadequately controlled hypertension,including high SBPV and/or uncontrolled SBP levels,may be related to increased coronary artery inflammation,HRPs,and OS in T2DM,leading to increased cardiovascular risk.Achieving both low SBPV and controlled SBP levels simultaneously,especially in individuals with T2DM and hypertension,warrants clinical attention.
基金supported by the National Key Research and Development Program of China(2022YFA1404400)the National Natural Science Foundation of China(62122072,12174368,61705216,62405306)+4 种基金Anhui Provincial Department of Science and Technology(202203a07020020,18030801138)Anhui Provincial Natural Science Foundation(2308085QA21,2408085QF187)the USTC Research Funds of the Double First-Class Initiative(YD2090002015)the Institute of Artificial Intelligence at Hefei Comprehensive National Science Center(23YGXT005)the Fundamental Research Funds for the Central Universities(WK2090000083).
文摘Ultrasound computed tomography(USCT)is a noninvasive biomedical imaging modality that offers insights into acoustic properties such as the sound speed(SS)and acoustic attenuation(AA)of the human body,enhancing diagnostic accuracy and therapy planning.Full waveform inversion(FWI)is a promising USCT image reconstruction method that optimizes the parameter fields of a wave propagation model via gradient-based optimization.However,twodimensional FWI methods are limited by their inability to account for three-dimensional wave propagation in the elevation direction,resulting in image artifacts.To address this problem,we propose a three-dimensional time-domain full waveform inversion algorithm to reconstruct the SS and AA distributions on the basis of a fractional Laplacian wave equation,adjoint field formulation,and gradient descent optimization.Validated by two sets of simulations,the proposed algorithm has potential for generating high-resolution and quantitative SS and AA distributions.This approach holds promise for clinical USCT applications,assisting early disease detection,precise abnormality localization,and optimized treatment planning,thus contributing to better healthcare outcomes.
基金supported by the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2021QNLM020001)the Major Scientificand Technological Projects of Shandong Energy Group(No.SNKJ2022A06-R23)+1 种基金the National Natural Science Foundation of China(No.42374164)the basic theoretical research of seismic wave imaging technology in complex oilfield of Changqing Oilfield Company(No.2023-10502)。
文摘The attenuation and anisotropy characteristics of real earth media give rise to amplitude loss and phase dispersion during seismic wave propagation.To address these effects on seismic imaging,viscoacoustic anisotropic wave equations expressed by the fractional Laplacian have been derived.However,the huge computational expense associated with multiple Fast Fourier transforms for solving these wave equations makes them unsuitable for industrial applications,especially in three dimensions.Therefore,we first derived a cost-effective pure-viscoacoustic wave equation expressed by the memory-variable in tilted transversely isotropic(TTI)media,based on the standard linear solid model.The newly derived wave equation featuring decoupled amplitude dissipation and phase dispersion terms,can be easily solved using the finite-difference method(FDM).Computational efficiency analyses demonstrate that wavefields simulated by our newly derived wave equation are more efficient compared to the previous pure-viscoacoustic TTI wave equations.The decoupling characteristics of the phase dispersion and amplitude dissipation of the proposed wave equation are illustrated in numerical tests.Additionally,we extend the newly derived wave equation to implement Q-compensated reverse time migration(RTM)in attenuating TTI media.Synthetic examples and field data test demonstrate that the proposed Qcompensated TTI RTM effectively migrate the effects of anisotropy and attenuation,providing highquality imaging results.
文摘Imagine a future where a single vaccine could protect you from a multitude of influenza strains,offering broad immunity with minimal risk.This vision is now closer to reality,thanks to a recent study that harnesses the power of cellular proteins to create a new generation of live attenuated vaccines that outsmart flu’s relentless mutations.
