BACKGROUND: Portopulmonary hypertension (PPH) is difficult to recognize in the early and middle stages because it is frequently asymptomatic. As right ventricular function is impaired in patients with moderate and sev...BACKGROUND: Portopulmonary hypertension (PPH) is difficult to recognize in the early and middle stages because it is frequently asymptomatic. As right ventricular function is impaired in patients with moderate and severe PPH, any dramatic hemodynamic changes in liver transplantation or other procedures may result in death from pulmonary and cardiac events. In this study, we investigated the prevalence of PPH in patients with portal hypertension (PHT) mainly caused by hepatitis B virus, and evaluated the effect of 2-dimensional Doppler echocardiography (2D-ECHO) in screening for PPH. METHODS: One hundred and five PHT patients received transthoracic 2D-ECHO preoperatively, systolic pulmonary arterial pressure (SPAP, normal range <30 mmHg) and pulmonary acceleration time (PAT, normal range >= 120 msec) were measured to screen for PPH (positive result: SPAP >= 30 mmHg and/or PAT <100 msec). Subsequently, pulmonary hemodynamic parameters were measured by right heart catheterization (RHC) for definitive diagnosis of PPH. The results of the two methods were compared to assess the screening effect of 2D-ECHO. RESULTS: The prevalence of PPH in this study was 3.8% (4/105). About 90% (95/105) of patients had a detectable tricuspid regurgitation by 2D-ECHO and the mean SPAP was 27.7 +/- 5.9 mmHg. Twenty-two of these 95 patients had an SPAP >30 mmHg. The mean PAT of all patients was 140 23 msec and 5 were <100 msec. Twenty-two patients were screened out by 2D-ECHO and 4 were diagnosed by RHC. A positive significant correlation (r=0.55, P<0.01) was found between SPAP measured by 2D-ECHO and mean pulmonary artery pressure (MPAP) measured by RHC, and a weak but significant negative correlation (r=-0.27, P=0.005) existed between PAT and pulmonary vascular resistance (PVR). The sensitivity, specificity, agreement rate, positive predictive value and negative predictive value of the screening test were 100%, 82%, 83%, 18% and 100%, respectively. CONCLUSIONS: The prevalence of PPH in this study is lower than in Western countries. As a screening test, 2D-ECHO has very high sensitivity and negative predictive value. A negative test result can directly be used to exclude PPH, while a positive result should be confirmed by RHC.展开更多
The purpose of this review is to provide a definitive account of small intestinal mucosal structure and interpretation. The coeliac lesion has been well known, but not well described to date and this review aims to id...The purpose of this review is to provide a definitive account of small intestinal mucosal structure and interpretation. The coeliac lesion has been well known, but not well described to date and this review aims to identify the interpretative difficulties which have arisen over time with the histological assessment of coeliac disease. In early coeliac interpretation, there were significant inaccuracies, particularly surrounding intraepithelial lymphocyte counts and the degree of villous flattening which occurred in the tissue. Many of these interpretive pitfalls are still encountered today, increasing the potential for diagnostic errors. These difficulties are mostly due to the fact that stained 2-dimensional sections can never truly represent the 3-dimensional framework of the intestinal tissue under investigation. Therefore, this review offers a critical account occasioned by these 2-dimensional interpretative errors and which, in our opinion, should in general be jettisoned. As a result, we leave a framework regarding the true 3-dimensional knowledge of mucosal structure accrued over the 70-year period of study, and one which is available for future reference.展开更多
In this paper, we obtain the strong law of large numbers for a 2-dimensional array of pairwise negatively dependent random variables which are not required to be identically distributed. We found the sufficient condit...In this paper, we obtain the strong law of large numbers for a 2-dimensional array of pairwise negatively dependent random variables which are not required to be identically distributed. We found the sufficient conditions of strong law of large numbers for the difference of random variables which independent and identically distributed conditions are regarded. In this study, we consider the limit as which is stronger than the limit as m× n→?∞ when m, n →?∞?are natural numbers.展开更多
Marijuana use as well as abuse is a significant public health and public safety concern in the United States and using hair to identify marijuana users and abusers has been gaining acceptance in a number of venues inc...Marijuana use as well as abuse is a significant public health and public safety concern in the United States and using hair to identify marijuana users and abusers has been gaining acceptance in a number of venues including workplace, court ordered, and substance abuse treatment monitoring. After the presentation of a fully validated 2-dimensional gas chromatography-tandem mass spectrometry method for the detection of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCA), the chief metabolite of the main psychoactive compound in marijuana, Δ9-tetrahydrocannabinol (THC), we evaluated the usefulness of fingernail clippings as an alternative specimen type to hair by the analysis of a set of 60 matched pairs of head hair and fingernail clippings. The limit of detection was 10 fg/mg, the limit of quantitation was 20 fg/mg, and the assay was linear from 20 fg/mg to 500 fg/mg. The intra- and inter-assay imprecision and bias studies at 4 different concentrations (50, 100, 500, and 1000 fg/mg) were acceptable where all % Target observations were within 16% of their expected concentrations and all %CV calculations were less than 13.5%. THCA was detectable in more fingernail specimens (53.3%) than hair specimens (46.7%) and the mean concentrations in nails were on average 4.9 times higher than in hair (1813 fg/mg and 364 fg/mg, respectively). The THCA concentrations in hair and nail were strongly associated (r = 0.974, P < 0.01, n = 60) and the association was significant. The study demonstrated that fingernail clippings are a suitable alternative specimen type to hair to monitor for marijuana use and abuse.展开更多
Most existing 2-dimensional barcodes are designed with a fixed shape and clear area.Having a fixed shape and clear area makes the barcode difficult to lay out with other text and pictures.To solve this problem,an amor...Most existing 2-dimensional barcodes are designed with a fixed shape and clear area.Having a fixed shape and clear area makes the barcode difficult to lay out with other text and pictures.To solve this problem,an amorphous 2-dimensional barcode is presented in this paper.The barcode uses encoding graph units to encode data.There are two key points in a 2-dimensional barcode:One is the encoding graph unit,the other is its encoding rules.Because encoding graph units of a 2-dimensional barcode are surrounded by other graphics,the units should be self-positioned and distinguished from other units.This paper presents an encoding graph unit generation algorithm,which is based on genetic algorithms.Encoding rules of the barcode are also given in this paper.Those rules include data encoding rules and encoding graph unit sequence arrangement rules.Data encoding rules are used to encode data to an encoding graph unit sequence.Encoding graph unit sequence arrangement rules are used to embed the unit sequence in the target picture.In addition to those rules,it also discussed the steps to restore encoding graph unit sequence from a picture.In the experiments section of this paper,an example is provided to encode a string and embed it in a car ad picture by the barcode.According to encoding rules of the barcode,those encoding graphic units can be scattered and embedded in a picture with other graphics,so amorphous 2-dimensional barcode has no fixed shape.Take advantage of this,designer can present a more elegant design to lay out barcodes with other graphic elements.展开更多
The elastic and functional coupling of heart and vessels makes the stroke work （SW） of the heart optimal. Speckle tracking imaging （STI） can evaluate the myocardial strain and function. We studied ventricular-vasc...The elastic and functional coupling of heart and vessels makes the stroke work （SW） of the heart optimal. Speckle tracking imaging （STI） can evaluate the myocardial strain and function. We studied ventricular-vascular coupling in 80 diabetic patients with different systolic function using STI. The patients were divided into two groups according to ejection fraction （EF）： the diabetes mel- litus with normal EF （DMN） group and the diabetes mellitus with abnormal EF （DMA） group. Forty-two volunteers served as control group. The relative wall thickness （RWT）, left ventricular mass index （LVMI）, stroke volume （SV）, SW, rate-pressure product （RPP）, systemic vascular resis- tance index （SVRI）, left ventricular end-systolic elastance （Ees）, effective arterial elasticity （Ea） and ventricular-vascular coupling index （VVI） were measured and calculated by conventional echocardi- ography. The longitudinal strain （LS） at basement （LSBA）, papillary muscle （LSvM） and cardiac apex （LSAv） was assessed with STI. It was found： （A） compared with control group, in DMN and DMA groups, LSBA, LSvM and LSAp decreased, and they were lower in DMA group. （B） VVI, RPP and SVRI increased, and they were higher in DMN group; Ees decreased, and it was lower in DMA group. （C） LSBA, LSpM, and LSAv had negative correlation with VVI. LSAp, RWT, LVMI and SW were independent predictors for VVI. The area under the receiver operating characteristic （ROC） curves was used for identification of DMA and DMN with LSBA, LSpM, and LSAp, and the area under the ROC of LSAp was the largest. This study supports that myocardial LS could reflect the ventricu- lar-vascular coupling. Different segments had an order to “respond to” the state of the coupling, and the cardiac apex might be the earliest.展开更多
Several 2-D displacement sensing methods are reviewed. As to the crossdiffraction grating, there is no absolute zero-reference. In regards to the optical fiber method,the output signal is affected greatly by the quali...Several 2-D displacement sensing methods are reviewed. As to the crossdiffraction grating, there is no absolute zero-reference. In regards to the optical fiber method,the output signal is affected greatly by the quality of the reflecting surface and it is hard to gethigh resolution. Considering the concentric-circle gratings, the displacement can only be gainedwith complicated calculating of the experiment data. Compared with the advantages and limitations ofthe methods above, a novel 2-D zero-reference mark is especially proposed and demonstrated. Thiskind of mark has an absolute zero-reference when used in pair, and the experimental result is simpleto dispose. By superimposing a pair of specially coded 2-D marks, the correct alignment position ofthe two marks can be detected by the maximum output of the sharp intensity peak. And each slope ofthe peak is of good linearity which can be used to achieve high resolution in positioning andalignment in two dimensions. Design and fabrication of such 2-D zero-reference marks are introducedin detail. The experiment results are agreed with the theoretical ones.展开更多
A new silicon micro flow sensor with multiple temperature sensing elements was proposed and numerically simulated in considering wide range flow measuring properties.The micro flow sensor has three pairs of temperatur...A new silicon micro flow sensor with multiple temperature sensing elements was proposed and numerically simulated in considering wide range flow measuring properties.The micro flow sensor has three pairs of temperature sensing elements with a central heater compared with typical sensor which has only a temperature sensing element on each side of a central heater.A numerical analysis of the micro flow sensor by Finite Difference Formulation for Heat Transfer Equation was performed.The nearest pair of temperature sensor showed very good linear sensitivity between 0 to 0.4m/s flow and saturated from 0.75m/s flow.However the furthest pair of temperature sensor showed some flow sensitivity even though the flow rate of 2.0m/s.Thus,this suggested new micro flow meter with multiple temperature sensing elements could be used as a thermal mass flow sensor which has accuracy sensitivity for very wide flow range.展开更多
We analyzed the SU(2)×SU(2)chiral model with mixed fundamental-adjoint action on the 2-dimensional(2-D)random lattice by using Monte-Carlo(M-C)simulation.The results sluw that the model behaves like the mixed SU(...We analyzed the SU(2)×SU(2)chiral model with mixed fundamental-adjoint action on the 2-dimensional(2-D)random lattice by using Monte-Carlo(M-C)simulation.The results sluw that the model behaves like the mixed SU(2)×SU(2)chiral model on the 2-D regular lattice,but the character of the phase transition seems to be different.展开更多
Human herpesviruses are double-stranded DNA viruses that are classified into nine species.More than 90%of adults are ever infected with one or more herpesviruses.The symptoms of infection with different herpesviruses ...Human herpesviruses are double-stranded DNA viruses that are classified into nine species.More than 90%of adults are ever infected with one or more herpesviruses.The symptoms of infection with different herpesviruses are diverse ranging from mild or asymptomatic infections to deadly diseases such as aggressive lymphomas and sarcomas.Timely and accurate detection of herpesvirus infection is critical for clinical management and treatment.In this study,we established a single-tube nonuple qPCR assay for detection of all nine herpesviruses using a 2-D multiplex qPCR method with a house-keeping gene as the internal control.The novel assay can detect and distinguish different herpesviruses with 30 to 300 copies per 25µL single-tube reaction,and does not cross-react with 20 other human viruses,including DNA and RNA viruses.The robustness of the novel assay was evaluated using 170 clinical samples.The novel assay showed a high consistency(100%)with the single qPCR assay for HHVs detection.The features of simple,rapid,high sensitivity,specificity,and low cost make this assay a high potential to be widely used in clinical diagnosis and patient treatment.展开更多
Recently, during the investigations on planetary oceans, Hirota-Satsuma-Ito-type models have been developed. In this paper, for a(2+1)-dimensional generalized variable-coefficient Hirota-Satsuma-Ito system describing ...Recently, during the investigations on planetary oceans, Hirota-Satsuma-Ito-type models have been developed. In this paper, for a(2+1)-dimensional generalized variable-coefficient Hirota-Satsuma-Ito system describing the fluid dynamics of shallow-water waves in an open ocean, non-characteristic movable singular manifold and symbolic computation enable an oceanic auto-B?cklund transformation with three sets of the oceanic solitonic solutions. The results rely on the oceanic variable coefficients in that system. Future oceanic observations might detect some nonlinear features predicted in this paper, and relevant oceanographic insights might be expected.展开更多
In this paper,we investigate the(2+1)-dimensional three-component long-wave-short-wave resonance interaction system,which describes complex systems and nonlinear wave phenomena in physics.By employing the Hirota bilin...In this paper,we investigate the(2+1)-dimensional three-component long-wave-short-wave resonance interaction system,which describes complex systems and nonlinear wave phenomena in physics.By employing the Hirota bilinear method,we derive the general nondegenerate N-soliton solution of the system,where each short-wave component contains N arbitrary functions of the independent variable y.The presence of these arbitrary functions in the analytical solution enables the construction of a wide range of nondegenerate soliton types.Finally,we illustrate the structural features of several novel nondegenerate solitons,including M-shaped,multiple double-hump,and sawtooth double-striped solitons,as well as interactions between nondegenerate solitons,such as dromion-like solitons and solitoffs,with the aid of figures.展开更多
In this work,we study wave state transitions of the(2+1)-dimensional Kortewegde Vries-Sawada-Kotera-Ramani(2KdVSKR)equation by analyzing the characteristic line and phase shift.By converting the wave parameters of the...In this work,we study wave state transitions of the(2+1)-dimensional Kortewegde Vries-Sawada-Kotera-Ramani(2KdVSKR)equation by analyzing the characteristic line and phase shift.By converting the wave parameters of the N-soliton solution into complex numbers,the breath wave solution is constructed.The lump wave solution is derived through the long wave limit method.Then,by choosing appropriate parameter values,we acquire a number of transformed nonlinear waves whose gradient relation is discussed according to the ratio of the wave parameters.Furthermore,we reveal transition mechanisms of the waves by exploring the nonlinear superposition of the solitary and periodic wave components.Subsequently,locality,oscillation properties and evolutionary phenomenon of the transformed waves are presented.And we also prove the change in the geometrical properties of the characteristic lines leads to the phenomena of wave evolution.Finally,for higher-order waves,a range of interaction models are depicted along with their evolutionary phenomena.And we demonstrate that their diversity is due to the fact that the solitary and periodic wave components produce different phase shifts caused by time evolution and collisions.展开更多
The fracture and migration patterns of direct roofs play a critical role in excavation stability and mining pressure.However,current methods fail to capture the irregular three-dimensional(3D)behavior of these roofs.I...The fracture and migration patterns of direct roofs play a critical role in excavation stability and mining pressure.However,current methods fail to capture the irregular three-dimensional(3D)behavior of these roofs.In this study,the problem was solved by introducing an innovative 2.5-dimensional(2.5D)Voronoi numerical simulation method,dividing rock layers into 2.5D Voronoi blocks and developing cohesive element-based failure models,supported by a strain-softening HoekeBrown model.The method was applied to the 8311 working face in the Taishan Mine in China,and its accuracy was confirmed through physical experiments.The following conclusions were drawn.The first roof break typically followed an"O-X"pattern.The direct roof did not break randomly over time;instead,it followed three distinct scenarios:(1)A complete break of the direct roof occurred,followed by a sequential collapse(ScenarioⅠ).(2)Regional irregular stacking in one area was followed by sequential collapse in other zones(ScenarioⅡ).(3)The staged breakdown of the direct roof led to separate and sequential collapses on the left and right flanks(ScenarioⅢ).Scenario I was quite common during the 400 m advance of the working face and occurred five times.The fracture characteristics in Scenario I led to widespread pressure on the hydraulic supports in the middle of the working face.Finally,the direct roof from the working face towards the goaf area underwent phases of overhanging,hinging,and collapsing plates.After the first and periodic breaks,the basic roof formed stable hinged plate structures reinforced by overhanging plates and irregular accumulations of the direct roof.展开更多
As a representative transition metal dichalcogenides(TMD),NiTe_(2)has an ultra-fast optical response,high carrier mobility,and excellent environmental stability.It has a broad application prospect in the fields of ene...As a representative transition metal dichalcogenides(TMD),NiTe_(2)has an ultra-fast optical response,high carrier mobility,and excellent environmental stability.It has a broad application prospect in the fields of ener-gy,biomedicine,optoelectronic devices,and so on.At present,there have been scant reports on the application of NiTe_(2)in the field of ultrafast photonics.In this work,NiTe_(2)was synthesized by chemical vapor deposition(CVD)and integrated with a tapered optical fiber to achieve mode-locking in an erbium-doped fiber laser(EDFL)and a thu-lium-doped fiber laser(TDFL).The mode-locked EDFL exhibited a pulse width of 678 fs and an output power of 3.92 mW.The pulse width of mode-locked TDFL was estimated to have a pulse width of 694 fs with an output power of 21.64 mW.These results demonstrate that NiTe_(2)is an effective saturable absorber material with potential applica-tions in the field of ultrafast optics.展开更多
Copper is a versatile material,commonly utilized in power transmission and electronic devices,but its relative high reactivity necessitates a long-lasting protective technique.Here,we report a method that combines pla...Copper is a versatile material,commonly utilized in power transmission and electronic devices,but its relative high reactivity necessitates a long-lasting protective technique.Here,we report a method that combines plasma-enhanced non-equilibrium magnetron sputtering physical vapor deposition(PEUMS-PVD)and anodization to construct a self-healing three-dimensional Ti/Al-doped TiO_(2)nanotubes/Ti_(3)AlC_(2)coating on the surface of Cu substrates.This novel strategy enhances the corrosion resistance of copper substrates in marine environments,with corrosion current densities of up to 4.5643×10^(−8)A/cm^(2).Among them,the doping of nano-aluminum particles makes the coating self-healing.The mechanistic analysis of the corrosion behaviors during early immersion experiments was conducted using electrochemical noise,and revealed that during the initial stages of coating immersion,uniform corrosion predominates,with a minor occurrence of localized corrosion.展开更多
Photocatalytic CO_(2)reduction into value-added chemicals holds significant promise for carbon-neutral recycling and solar-to-fuel conversion.Enhancing reaction efficiency by manipulating charge transfer is a key appr...Photocatalytic CO_(2)reduction into value-added chemicals holds significant promise for carbon-neutral recycling and solar-to-fuel conversion.Enhancing reaction efficiency by manipulating charge transfer is a key approach to unlocking this potential.In this work,we construct a two-dimensional/twodimensional(2D/2D)FeSe_(2)/protonated carbon nitride(FeSe_(2)/PCN)heterostructure to promote the interfacial charge transfer dynamics,leading to a four-fold improved conversion efficiency of photocatalytic CO_(2)reduction with near 100%CO selectivity.Combining in situ X-ray photoelectron spectroscopy,in situ soft X-ray absorption spectroscopy,and femtosecond transient absorption spectroscopy,it is revealed that FeSe_(2)acts as an electron acceptor upon photoexcitation,introducing an additional electron transfer pathway from PCN to FeSe_(2)that suppresses radiative recombination and promotes charge transfer.In situ X-ray absorption fine structure spectroscopy,in situ diffuse reflectance infrared Fourier transform spectroscopy,and density functional theory calculation further unravel that the electron-enriched FeSe_(2)functions as the active sites for CO_(2)activation and significantly reduces the energy barrier of key intermediate COOH*formation,which is the rate-determined step for CO generation.This work underscores the importance of regulating photocarrier relaxation pathways to achieve effective spatial charge separation for promoted photocatalytic CO_(2)reduction and demonstrates the powerful functions of in situ spectroscopies in in-depth understanding of the photocatalytic mechanism.展开更多
The single-layer Ti_(3)C_(2)T_(x)/MXene has become a special electromagnetic wave absorber near the terahertz band because of its abundant surface groups and excellent conductivity.However,the macro-preparation of sin...The single-layer Ti_(3)C_(2)T_(x)/MXene has become a special electromagnetic wave absorber near the terahertz band because of its abundant surface groups and excellent conductivity.However,the macro-preparation of single-layer Ti_(3)C_(2)T_(x)/MXene shows significantly difficult to influence its application.The two-dimensional Ti_(3)C_(2)T_(x)is easily prepared to have high production,but its weak absorption ability due to high surface conductivity also restricts its application.To realize the strong electromagnetic wave absorption of two-dimensional Ti_(3)C_(2)T_(x)/MXene,a new strategy with magnetic FeNi nanoparticles decorating Ti_(3)C_(2)T_(x)/MXene composites(FeNi-Ti_(3)C_(2)T_(x))were proposed and the effective electromagnetic wave absorption features covering 170-220 GHz that means the absorption band width reach 50 GHz.With an absorber composite film thickness being only 0.6 mm,the absorptivity of the composite is enhanced with the increase of decorating FeNi nanoparticles and promote up to 75%when the FeNi nanoparticles loading content reaches 30 wt%.The improvement of absorption is attributed to the introduction of soft magnetic FeNi to adjust the high surface conductivity of MXene and improve the electromagnetic balance of the absorber.展开更多
Microplastics(MPs)are ubiquitous in the environment,continuously undergo aging processes and release toxic chemical substances.Understanding the environmental behaviors of MPs is critical to accurately evaluate their ...Microplastics(MPs)are ubiquitous in the environment,continuously undergo aging processes and release toxic chemical substances.Understanding the environmental behaviors of MPs is critical to accurately evaluate their long-term ecological risk.Generalized twodimensional correlation spectroscopy(2D-COS)is a powerful tool for MPs studies,which can dig more comprehensive information hiding in the conventional one-dimensional spectra,such as infrared(IR)and Raman spectra.The recent applications of 2D-COS in analyzing the behaviors and fates of MPs in the environment,including their aging processes,and interactions with natural organicmatter(NOM)or other chemical substances,were summarized systematically.The main requirements and limitations of current approaches for exploring these processes are discussed,and the corresponding strategies to address these limitations and drawbacks are proposed as well.Finally,new trends of 2D-COS are prospected for analyzing the properties and behaviors of MPs in both natural and artificial environmental processes.展开更多
We propose and investigate a novel stable two-dimensional(2D)AlO_(2)with anomalous stoichiometric ratios based on first-principles calculation.2D AlO_(2)has metallic properties.It possesses the rare in-plane and out-o...We propose and investigate a novel stable two-dimensional(2D)AlO_(2)with anomalous stoichiometric ratios based on first-principles calculation.2D AlO_(2)has metallic properties.It possesses the rare in-plane and out-of-plane negative Poisson's ratio(NPR)phenomenon,originating from its special sawtooth-like structure.The absolute value of the NPR decreases as the number of layers increases.The adsorption of volatile organic compounds(VOCs)including CH_(2)O,C_(2)H_(3)Cl and C_(6)H_(6)by AlO_(2)exhibit small adsorption distance,large adsorption energy,large charge transfer and significant density of states(DOS)changes,indicating the presence of strong interactions.The desorption time of each gas molecule on the AlO_(2)surface is also evaluated,and the results further suggest that the desorption of VOCs can be controlled by changing the temperature to achieve the recycling of AlO_(2).These interesting properties make 2D AlO_(2)a promising material for electronic,mechanical and sensing applications for VOCs.展开更多
基金supported by a grant from the Shanghai Municipal Health Bureau(No.054041)
文摘BACKGROUND: Portopulmonary hypertension (PPH) is difficult to recognize in the early and middle stages because it is frequently asymptomatic. As right ventricular function is impaired in patients with moderate and severe PPH, any dramatic hemodynamic changes in liver transplantation or other procedures may result in death from pulmonary and cardiac events. In this study, we investigated the prevalence of PPH in patients with portal hypertension (PHT) mainly caused by hepatitis B virus, and evaluated the effect of 2-dimensional Doppler echocardiography (2D-ECHO) in screening for PPH. METHODS: One hundred and five PHT patients received transthoracic 2D-ECHO preoperatively, systolic pulmonary arterial pressure (SPAP, normal range <30 mmHg) and pulmonary acceleration time (PAT, normal range >= 120 msec) were measured to screen for PPH (positive result: SPAP >= 30 mmHg and/or PAT <100 msec). Subsequently, pulmonary hemodynamic parameters were measured by right heart catheterization (RHC) for definitive diagnosis of PPH. The results of the two methods were compared to assess the screening effect of 2D-ECHO. RESULTS: The prevalence of PPH in this study was 3.8% (4/105). About 90% (95/105) of patients had a detectable tricuspid regurgitation by 2D-ECHO and the mean SPAP was 27.7 +/- 5.9 mmHg. Twenty-two of these 95 patients had an SPAP >30 mmHg. The mean PAT of all patients was 140 23 msec and 5 were <100 msec. Twenty-two patients were screened out by 2D-ECHO and 4 were diagnosed by RHC. A positive significant correlation (r=0.55, P<0.01) was found between SPAP measured by 2D-ECHO and mean pulmonary artery pressure (MPAP) measured by RHC, and a weak but significant negative correlation (r=-0.27, P=0.005) existed between PAT and pulmonary vascular resistance (PVR). The sensitivity, specificity, agreement rate, positive predictive value and negative predictive value of the screening test were 100%, 82%, 83%, 18% and 100%, respectively. CONCLUSIONS: The prevalence of PPH in this study is lower than in Western countries. As a screening test, 2D-ECHO has very high sensitivity and negative predictive value. A negative test result can directly be used to exclude PPH, while a positive result should be confirmed by RHC.
文摘The purpose of this review is to provide a definitive account of small intestinal mucosal structure and interpretation. The coeliac lesion has been well known, but not well described to date and this review aims to identify the interpretative difficulties which have arisen over time with the histological assessment of coeliac disease. In early coeliac interpretation, there were significant inaccuracies, particularly surrounding intraepithelial lymphocyte counts and the degree of villous flattening which occurred in the tissue. Many of these interpretive pitfalls are still encountered today, increasing the potential for diagnostic errors. These difficulties are mostly due to the fact that stained 2-dimensional sections can never truly represent the 3-dimensional framework of the intestinal tissue under investigation. Therefore, this review offers a critical account occasioned by these 2-dimensional interpretative errors and which, in our opinion, should in general be jettisoned. As a result, we leave a framework regarding the true 3-dimensional knowledge of mucosal structure accrued over the 70-year period of study, and one which is available for future reference.
文摘In this paper, we obtain the strong law of large numbers for a 2-dimensional array of pairwise negatively dependent random variables which are not required to be identically distributed. We found the sufficient conditions of strong law of large numbers for the difference of random variables which independent and identically distributed conditions are regarded. In this study, we consider the limit as which is stronger than the limit as m× n→?∞ when m, n →?∞?are natural numbers.
文摘Marijuana use as well as abuse is a significant public health and public safety concern in the United States and using hair to identify marijuana users and abusers has been gaining acceptance in a number of venues including workplace, court ordered, and substance abuse treatment monitoring. After the presentation of a fully validated 2-dimensional gas chromatography-tandem mass spectrometry method for the detection of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCA), the chief metabolite of the main psychoactive compound in marijuana, Δ9-tetrahydrocannabinol (THC), we evaluated the usefulness of fingernail clippings as an alternative specimen type to hair by the analysis of a set of 60 matched pairs of head hair and fingernail clippings. The limit of detection was 10 fg/mg, the limit of quantitation was 20 fg/mg, and the assay was linear from 20 fg/mg to 500 fg/mg. The intra- and inter-assay imprecision and bias studies at 4 different concentrations (50, 100, 500, and 1000 fg/mg) were acceptable where all % Target observations were within 16% of their expected concentrations and all %CV calculations were less than 13.5%. THCA was detectable in more fingernail specimens (53.3%) than hair specimens (46.7%) and the mean concentrations in nails were on average 4.9 times higher than in hair (1813 fg/mg and 364 fg/mg, respectively). The THCA concentrations in hair and nail were strongly associated (r = 0.974, P < 0.01, n = 60) and the association was significant. The study demonstrated that fingernail clippings are a suitable alternative specimen type to hair to monitor for marijuana use and abuse.
基金This work was funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Most existing 2-dimensional barcodes are designed with a fixed shape and clear area.Having a fixed shape and clear area makes the barcode difficult to lay out with other text and pictures.To solve this problem,an amorphous 2-dimensional barcode is presented in this paper.The barcode uses encoding graph units to encode data.There are two key points in a 2-dimensional barcode:One is the encoding graph unit,the other is its encoding rules.Because encoding graph units of a 2-dimensional barcode are surrounded by other graphics,the units should be self-positioned and distinguished from other units.This paper presents an encoding graph unit generation algorithm,which is based on genetic algorithms.Encoding rules of the barcode are also given in this paper.Those rules include data encoding rules and encoding graph unit sequence arrangement rules.Data encoding rules are used to encode data to an encoding graph unit sequence.Encoding graph unit sequence arrangement rules are used to embed the unit sequence in the target picture.In addition to those rules,it also discussed the steps to restore encoding graph unit sequence from a picture.In the experiments section of this paper,an example is provided to encode a string and embed it in a car ad picture by the barcode.According to encoding rules of the barcode,those encoding graphic units can be scattered and embedded in a picture with other graphics,so amorphous 2-dimensional barcode has no fixed shape.Take advantage of this,designer can present a more elegant design to lay out barcodes with other graphic elements.
基金supported by a grant from the Shanghai Health and Family Planning Commission,China(No.201440290)
文摘The elastic and functional coupling of heart and vessels makes the stroke work （SW） of the heart optimal. Speckle tracking imaging （STI） can evaluate the myocardial strain and function. We studied ventricular-vascular coupling in 80 diabetic patients with different systolic function using STI. The patients were divided into two groups according to ejection fraction （EF）： the diabetes mel- litus with normal EF （DMN） group and the diabetes mellitus with abnormal EF （DMA） group. Forty-two volunteers served as control group. The relative wall thickness （RWT）, left ventricular mass index （LVMI）, stroke volume （SV）, SW, rate-pressure product （RPP）, systemic vascular resis- tance index （SVRI）, left ventricular end-systolic elastance （Ees）, effective arterial elasticity （Ea） and ventricular-vascular coupling index （VVI） were measured and calculated by conventional echocardi- ography. The longitudinal strain （LS） at basement （LSBA）, papillary muscle （LSvM） and cardiac apex （LSAv） was assessed with STI. It was found： （A） compared with control group, in DMN and DMA groups, LSBA, LSvM and LSAp decreased, and they were lower in DMA group. （B） VVI, RPP and SVRI increased, and they were higher in DMN group; Ees decreased, and it was lower in DMA group. （C） LSBA, LSpM, and LSAv had negative correlation with VVI. LSAp, RWT, LVMI and SW were independent predictors for VVI. The area under the receiver operating characteristic （ROC） curves was used for identification of DMA and DMN with LSBA, LSpM, and LSAp, and the area under the ROC of LSAp was the largest. This study supports that myocardial LS could reflect the ventricu- lar-vascular coupling. Different segments had an order to “respond to” the state of the coupling, and the cardiac apex might be the earliest.
基金This project is supported by National Natural Science Foundation of China(No.50335050, No.50275140)Specialized Research Foundation for Doctoral Program of Higher Education (SRFDP) of China(No. 20030358020).
文摘Several 2-D displacement sensing methods are reviewed. As to the crossdiffraction grating, there is no absolute zero-reference. In regards to the optical fiber method,the output signal is affected greatly by the quality of the reflecting surface and it is hard to gethigh resolution. Considering the concentric-circle gratings, the displacement can only be gainedwith complicated calculating of the experiment data. Compared with the advantages and limitations ofthe methods above, a novel 2-D zero-reference mark is especially proposed and demonstrated. Thiskind of mark has an absolute zero-reference when used in pair, and the experimental result is simpleto dispose. By superimposing a pair of specially coded 2-D marks, the correct alignment position ofthe two marks can be detected by the maximum output of the sharp intensity peak. And each slope ofthe peak is of good linearity which can be used to achieve high resolution in positioning andalignment in two dimensions. Design and fabrication of such 2-D zero-reference marks are introducedin detail. The experiment results are agreed with the theoretical ones.
文摘A new silicon micro flow sensor with multiple temperature sensing elements was proposed and numerically simulated in considering wide range flow measuring properties.The micro flow sensor has three pairs of temperature sensing elements with a central heater compared with typical sensor which has only a temperature sensing element on each side of a central heater.A numerical analysis of the micro flow sensor by Finite Difference Formulation for Heat Transfer Equation was performed.The nearest pair of temperature sensor showed very good linear sensitivity between 0 to 0.4m/s flow and saturated from 0.75m/s flow.However the furthest pair of temperature sensor showed some flow sensitivity even though the flow rate of 2.0m/s.Thus,this suggested new micro flow meter with multiple temperature sensing elements could be used as a thermal mass flow sensor which has accuracy sensitivity for very wide flow range.
文摘We analyzed the SU(2)×SU(2)chiral model with mixed fundamental-adjoint action on the 2-dimensional(2-D)random lattice by using Monte-Carlo(M-C)simulation.The results sluw that the model behaves like the mixed SU(2)×SU(2)chiral model on the 2-D regular lattice,but the character of the phase transition seems to be different.
基金supported by the grants from the National Science and Technology Major Project of China (2019YFC1200603, and 2017ZX10103009-002)
文摘Human herpesviruses are double-stranded DNA viruses that are classified into nine species.More than 90%of adults are ever infected with one or more herpesviruses.The symptoms of infection with different herpesviruses are diverse ranging from mild or asymptomatic infections to deadly diseases such as aggressive lymphomas and sarcomas.Timely and accurate detection of herpesvirus infection is critical for clinical management and treatment.In this study,we established a single-tube nonuple qPCR assay for detection of all nine herpesviruses using a 2-D multiplex qPCR method with a house-keeping gene as the internal control.The novel assay can detect and distinguish different herpesviruses with 30 to 300 copies per 25µL single-tube reaction,and does not cross-react with 20 other human viruses,including DNA and RNA viruses.The robustness of the novel assay was evaluated using 170 clinical samples.The novel assay showed a high consistency(100%)with the single qPCR assay for HHVs detection.The features of simple,rapid,high sensitivity,specificity,and low cost make this assay a high potential to be widely used in clinical diagnosis and patient treatment.
基金financially supported by the Scientific Research Foundation of North China University of Technology (Grant Nos.11005136024XN147-87 and 110051360024XN151-86)。
文摘Recently, during the investigations on planetary oceans, Hirota-Satsuma-Ito-type models have been developed. In this paper, for a(2+1)-dimensional generalized variable-coefficient Hirota-Satsuma-Ito system describing the fluid dynamics of shallow-water waves in an open ocean, non-characteristic movable singular manifold and symbolic computation enable an oceanic auto-B?cklund transformation with three sets of the oceanic solitonic solutions. The results rely on the oceanic variable coefficients in that system. Future oceanic observations might detect some nonlinear features predicted in this paper, and relevant oceanographic insights might be expected.
基金supported by the National Natural Science Foundation of China,Grant No.12375006。
文摘In this paper,we investigate the(2+1)-dimensional three-component long-wave-short-wave resonance interaction system,which describes complex systems and nonlinear wave phenomena in physics.By employing the Hirota bilinear method,we derive the general nondegenerate N-soliton solution of the system,where each short-wave component contains N arbitrary functions of the independent variable y.The presence of these arbitrary functions in the analytical solution enables the construction of a wide range of nondegenerate soliton types.Finally,we illustrate the structural features of several novel nondegenerate solitons,including M-shaped,multiple double-hump,and sawtooth double-striped solitons,as well as interactions between nondegenerate solitons,such as dromion-like solitons and solitoffs,with the aid of figures.
基金supported by the National Natural Science Foundation of China(12371255,11975306)the Xuzhou Basic Research Program Project(KC23048)+1 种基金the Six Talent Peaks Project in Jiangsu Province(JY-059)the 333 Project in Jiangsu Province and the Fundamental Research Funds for the Central Universities of CUMT(2024ZDPYJQ1003).
文摘In this work,we study wave state transitions of the(2+1)-dimensional Kortewegde Vries-Sawada-Kotera-Ramani(2KdVSKR)equation by analyzing the characteristic line and phase shift.By converting the wave parameters of the N-soliton solution into complex numbers,the breath wave solution is constructed.The lump wave solution is derived through the long wave limit method.Then,by choosing appropriate parameter values,we acquire a number of transformed nonlinear waves whose gradient relation is discussed according to the ratio of the wave parameters.Furthermore,we reveal transition mechanisms of the waves by exploring the nonlinear superposition of the solitary and periodic wave components.Subsequently,locality,oscillation properties and evolutionary phenomenon of the transformed waves are presented.And we also prove the change in the geometrical properties of the characteristic lines leads to the phenomena of wave evolution.Finally,for higher-order waves,a range of interaction models are depicted along with their evolutionary phenomena.And we demonstrate that their diversity is due to the fact that the solitary and periodic wave components produce different phase shifts caused by time evolution and collisions.
基金supported by the Autonomous General Projects of the State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,China(Grant No.2011DA105287-MS202209)the National Natural Science Foundation of China,China(Grant Nos.52304149 and 52204127).
文摘The fracture and migration patterns of direct roofs play a critical role in excavation stability and mining pressure.However,current methods fail to capture the irregular three-dimensional(3D)behavior of these roofs.In this study,the problem was solved by introducing an innovative 2.5-dimensional(2.5D)Voronoi numerical simulation method,dividing rock layers into 2.5D Voronoi blocks and developing cohesive element-based failure models,supported by a strain-softening HoekeBrown model.The method was applied to the 8311 working face in the Taishan Mine in China,and its accuracy was confirmed through physical experiments.The following conclusions were drawn.The first roof break typically followed an"O-X"pattern.The direct roof did not break randomly over time;instead,it followed three distinct scenarios:(1)A complete break of the direct roof occurred,followed by a sequential collapse(ScenarioⅠ).(2)Regional irregular stacking in one area was followed by sequential collapse in other zones(ScenarioⅡ).(3)The staged breakdown of the direct roof led to separate and sequential collapses on the left and right flanks(ScenarioⅢ).Scenario I was quite common during the 400 m advance of the working face and occurred five times.The fracture characteristics in Scenario I led to widespread pressure on the hydraulic supports in the middle of the working face.Finally,the direct roof from the working face towards the goaf area underwent phases of overhanging,hinging,and collapsing plates.After the first and periodic breaks,the basic roof formed stable hinged plate structures reinforced by overhanging plates and irregular accumulations of the direct roof.
基金Supported by Guangdong Basic and Applied Basic Research Fund,China(2024A1515012429)。
文摘As a representative transition metal dichalcogenides(TMD),NiTe_(2)has an ultra-fast optical response,high carrier mobility,and excellent environmental stability.It has a broad application prospect in the fields of ener-gy,biomedicine,optoelectronic devices,and so on.At present,there have been scant reports on the application of NiTe_(2)in the field of ultrafast photonics.In this work,NiTe_(2)was synthesized by chemical vapor deposition(CVD)and integrated with a tapered optical fiber to achieve mode-locking in an erbium-doped fiber laser(EDFL)and a thu-lium-doped fiber laser(TDFL).The mode-locked EDFL exhibited a pulse width of 678 fs and an output power of 3.92 mW.The pulse width of mode-locked TDFL was estimated to have a pulse width of 694 fs with an output power of 21.64 mW.These results demonstrate that NiTe_(2)is an effective saturable absorber material with potential applica-tions in the field of ultrafast optics.
基金Projects(42106051,42006046,U2106206) supported by the National Natural Science Foundation of ChinaProject(22373501D) supported by Hebei Provincial Key R&D Program,China。
文摘Copper is a versatile material,commonly utilized in power transmission and electronic devices,but its relative high reactivity necessitates a long-lasting protective technique.Here,we report a method that combines plasma-enhanced non-equilibrium magnetron sputtering physical vapor deposition(PEUMS-PVD)and anodization to construct a self-healing three-dimensional Ti/Al-doped TiO_(2)nanotubes/Ti_(3)AlC_(2)coating on the surface of Cu substrates.This novel strategy enhances the corrosion resistance of copper substrates in marine environments,with corrosion current densities of up to 4.5643×10^(−8)A/cm^(2).Among them,the doping of nano-aluminum particles makes the coating self-healing.The mechanistic analysis of the corrosion behaviors during early immersion experiments was conducted using electrochemical noise,and revealed that during the initial stages of coating immersion,uniform corrosion predominates,with a minor occurrence of localized corrosion.
基金supported by the National Natural Science Foundation of China(12241502,92045301)Fundamental Research Funds for the Central Universities(20720220010)+7 种基金USTC Research Funds of the Double First-Class Initiative(YD2310002012)the Launching Special Funds of Scientific Research for Introduced Talents from University of Science and Technology of China(KY2310000060)National Key Research and Development Program of China(2019YFA0405602)Anhui Provincial Natural Science Foundation(2408085QB049)the Instruments Center for Physical Science and USTC Center for Micro and Nanoscale Research and Fabrication,University of Science and Technology of Chinathe solid supports from the BL03U,BL10B,and BL12B beamlines of the National Synchrotron Radiation Laboratory(NSRL,Hefei)the Shanghai Synchrotron Radiation Facility(SSRF,Shanghai)of BL11B(https://cstr.cn/31124.02.SSRF.BL11B)and BL14W1(https://cstr.cn/31124.02.SSRF.BL14W1)beamlines for the assistance on XAFS measurementsAnhui Chuangpu Instruments Co.,Ltd.for the assistance in the test of Table XAFS。
文摘Photocatalytic CO_(2)reduction into value-added chemicals holds significant promise for carbon-neutral recycling and solar-to-fuel conversion.Enhancing reaction efficiency by manipulating charge transfer is a key approach to unlocking this potential.In this work,we construct a two-dimensional/twodimensional(2D/2D)FeSe_(2)/protonated carbon nitride(FeSe_(2)/PCN)heterostructure to promote the interfacial charge transfer dynamics,leading to a four-fold improved conversion efficiency of photocatalytic CO_(2)reduction with near 100%CO selectivity.Combining in situ X-ray photoelectron spectroscopy,in situ soft X-ray absorption spectroscopy,and femtosecond transient absorption spectroscopy,it is revealed that FeSe_(2)acts as an electron acceptor upon photoexcitation,introducing an additional electron transfer pathway from PCN to FeSe_(2)that suppresses radiative recombination and promotes charge transfer.In situ X-ray absorption fine structure spectroscopy,in situ diffuse reflectance infrared Fourier transform spectroscopy,and density functional theory calculation further unravel that the electron-enriched FeSe_(2)functions as the active sites for CO_(2)activation and significantly reduces the energy barrier of key intermediate COOH*formation,which is the rate-determined step for CO generation.This work underscores the importance of regulating photocarrier relaxation pathways to achieve effective spatial charge separation for promoted photocatalytic CO_(2)reduction and demonstrates the powerful functions of in situ spectroscopies in in-depth understanding of the photocatalytic mechanism.
基金supported by the National Key R&D Program of China(Nos.2023YFF0718303 and 2022YFB3504804)the National Natural Science Foundation of China(Nos.51871219,52031014 and 52401255)the Science and Technology Project of Shenyang City(No.22-101-0-27).
文摘The single-layer Ti_(3)C_(2)T_(x)/MXene has become a special electromagnetic wave absorber near the terahertz band because of its abundant surface groups and excellent conductivity.However,the macro-preparation of single-layer Ti_(3)C_(2)T_(x)/MXene shows significantly difficult to influence its application.The two-dimensional Ti_(3)C_(2)T_(x)is easily prepared to have high production,but its weak absorption ability due to high surface conductivity also restricts its application.To realize the strong electromagnetic wave absorption of two-dimensional Ti_(3)C_(2)T_(x)/MXene,a new strategy with magnetic FeNi nanoparticles decorating Ti_(3)C_(2)T_(x)/MXene composites(FeNi-Ti_(3)C_(2)T_(x))were proposed and the effective electromagnetic wave absorption features covering 170-220 GHz that means the absorption band width reach 50 GHz.With an absorber composite film thickness being only 0.6 mm,the absorptivity of the composite is enhanced with the increase of decorating FeNi nanoparticles and promote up to 75%when the FeNi nanoparticles loading content reaches 30 wt%.The improvement of absorption is attributed to the introduction of soft magnetic FeNi to adjust the high surface conductivity of MXene and improve the electromagnetic balance of the absorber.
基金supported by the National Natural Science Foundation of China(Nos.52293444 and 22076209)the Key R&D Project of Ningxia(No.2021BEG02006).
文摘Microplastics(MPs)are ubiquitous in the environment,continuously undergo aging processes and release toxic chemical substances.Understanding the environmental behaviors of MPs is critical to accurately evaluate their long-term ecological risk.Generalized twodimensional correlation spectroscopy(2D-COS)is a powerful tool for MPs studies,which can dig more comprehensive information hiding in the conventional one-dimensional spectra,such as infrared(IR)and Raman spectra.The recent applications of 2D-COS in analyzing the behaviors and fates of MPs in the environment,including their aging processes,and interactions with natural organicmatter(NOM)or other chemical substances,were summarized systematically.The main requirements and limitations of current approaches for exploring these processes are discussed,and the corresponding strategies to address these limitations and drawbacks are proposed as well.Finally,new trends of 2D-COS are prospected for analyzing the properties and behaviors of MPs in both natural and artificial environmental processes.
基金financially supported by National Natural Science Foundation of China(No.22275149)Fundamental Research Funds for the Central Universities(No.SWU118105)the Next-Generation Advanced Energy Materials Program of BatteroTech Co.,Ltd.
文摘We propose and investigate a novel stable two-dimensional(2D)AlO_(2)with anomalous stoichiometric ratios based on first-principles calculation.2D AlO_(2)has metallic properties.It possesses the rare in-plane and out-of-plane negative Poisson's ratio(NPR)phenomenon,originating from its special sawtooth-like structure.The absolute value of the NPR decreases as the number of layers increases.The adsorption of volatile organic compounds(VOCs)including CH_(2)O,C_(2)H_(3)Cl and C_(6)H_(6)by AlO_(2)exhibit small adsorption distance,large adsorption energy,large charge transfer and significant density of states(DOS)changes,indicating the presence of strong interactions.The desorption time of each gas molecule on the AlO_(2)surface is also evaluated,and the results further suggest that the desorption of VOCs can be controlled by changing the temperature to achieve the recycling of AlO_(2).These interesting properties make 2D AlO_(2)a promising material for electronic,mechanical and sensing applications for VOCs.
