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The NMDA subtype glutamate receptors (NMDARs) play important roles in both physiological and pathologic processes in the brain. Compared with their critical roles in synaptic modifications and excitotoxicity in excitatory neurons, much less is understood about the functional contributions of NMDARs to the inhibitory GABAergic neurons. By using selective NMDAR inhibitors and potentiators, we here show that NMDARs bidirectionally modulate the intrinsic excitability (defined as spontaneous/evoked spiking activity and EPSP-spike coupling) in inhibitory GABAergic neurons in adult male and female mice. This modulation depends on GluN2C/2D- but not GluN2A/2B-containing NMDARs. We further show that NMDAR modulator EU1794-4 mostly enhances extrasynaptic NMDAR activity, and by using it we demonstrate a significant contribution of extrasynaptic NMDARs to the modulation of intrinsic excitability in inhibitory neurons. Together, this bidirectional modulation of intrinsic excitability reveals a previously less appreciated importance of NMDARs in the second-to-second functioning of inhibitory GABAergic neurons.SIGNIFICANCE STATEMENTNMDA subtype of glutamate receptors (NMDARs) have important roles in brain functions, including both physiological and pathologic ones. The role of NMDARs in inhibitory neurons has been less elucidated compared with that in excitatory neurons. Our results demonstrate the importance of GluN2C/GluN2D-containing but not GluN2A/GluN2B-containing extrasynaptic NMDARs in modulating the intrinsic excitability of inhibitory neurons. These results further suggest distinct contributions of subsynaptic locations and subunit compositions of NMDARs to their functions in excitatory and inhibitory neurons. The above findings have implications for better understanding of brain diseases, such as schizophrenia.

Fluoride-mediated synthesis in the inorganic hydrothermal system has been proposed for preparing large crystals of layered Na/K-JDF-L1 with lamellar morphology. The protonated JDF-L1 crystals derived from their layered precursors are structurally modified by 1,6-hexanediamine intercalation under mild hydrothermal conditions. All the materials mentioned are characterized by XRD, FESEM, EDX/ICP-AES, and TGA–DSC. It is concluded that the combination of fluorides with low alkalinity (pH ca.10.0) and crystallization temperature (200 °C) facilitates the oriented growth of metastable layered phase Na/K-JDF-L1, yielding regular lamellar crystals with square-sheet structure in two-dimensions of ca. 15 × 15 μm. Data on Na/K-JDF-L1 structure are presented for identification of the most probable tetragonal space group, P4212, corresponding to the highest crystallographic symmetry. It is also revealed that amine intercalation of relevant H-JDF-L1 by the hydrothermal process leads to the formation of layered titanosilicate materials with an ordered redistribution of the dominant interlayer space (d001) shifting from 10.674 to 15.620 A.

Blood purification refers to the extra corporeal therapies of removing potentially toxic substances, in which blood is circulated through an adsorption system loading separation materials. High-efficient inexpensive separation materials are critical to success. In this review, separation materials such as polymers and nanomaterials are summarized and compared. Combining the advantages of the adsorptive membranes and nanomaterials, organic–inorganic hybrid/blend membranes have been developed explosively. These hybrid/blend membranes have both the characteristics of high permeability, easy fabrication, good biocompatibility of adsorptive membranes, and characteristics of fast adsorption rate and high adsorption capacity of nanomaterials. The preparation and modification methodology of the separation materials is reviewed. For affinity separation materials, the relationship of ligand chemistry, ligand density and pores of the matrix is discussed. This paper also summarizes some interesting applications in separation materials for removal of bilirubin, endotoxin, toxic metal ions, cytokine, etc.

Summary: It has been proposed that sound information is separately streamed into onset and offset pathways for parallel processing. However, how offset responses contribute to auditory perception remains unclear. Here, loose-patch and whole-cell recordings in awake mouse primary auditory cortex (A1) reveal that a subset of pyramidal neurons exhibit a transient “Off” response, with its onset tightly time-locked to the sound termination and its frequency tuning similar to that of the transient “On” response. Both responses are characterized by excitation briefly followed by inhibition, with the latter mediated by parvalbumin (PV) inhibitory neurons. Optogenetically manipulating sound-evoked A1 responses at different temporal phases or artificially creating phantom sounds in A1 further reveals that the A1 phasic On and Off responses are critical for perceptual discrimination of sound duration. Our results suggest that perception of sound duration is dependent on precisely encoding its onset and offset timings by phasic On and Off responses.

In this work, we propose a facile, fast and large-scale synthesis of β-Mo2C catalysts (about 100 grams). The current approach uses a simple solid mixture of (NH4)6Mo7O24·4H2O and carbon nanotubes (CNTs) as a precursor and employs a fast heating rate method without holding time. Moreover, there was no need for passivating the carbide products. A series of β-Mo2C/CNT catalysts (denoted as MoC-5, -15, -30 and -60) were successfully prepared from the precursors with the Mo content ranging from 5 to 60 wt% and their catalytic activities for dry reforming of methane (DRM) were evaluated. CH4-TPSR and CO2-TPO over the fresh samples proved that the abilities of CH4 dissociation and oxidation resistance of β-Mo2C were greatly enhanced by compositing with CNTs. It was also found that these abilities were dependent on the Mo content, the particle size and the interaction between β-Mo2C and CNTs. Among these β-Mo2C/CNT catalysts, MoC-30 showed the best catalytic stability for DRM, attributed to its high activity for CH4 dissociation and high resistance to oxidation. Additionally, it is worth noting that the catalytic stability of monometallic MoC-30 was found to be superior to that of bimetallic Ni/β-Mo2C (recently known to be an efficient non-noble metal catalyst for DRM).

This study presented a new carbon source, viz. p-phenylenediamine (pPDA), to synthesize nanosized Ni2P on carbon support by a carbothermal reduction method. For the first time, dispersed of Ni2P wi...

In this work, Pt loaded Na+ doped graphitic carbon nitride (g-C3N4) catalyst for photocatalytic water splitting to produce H2 and H2O2 simultaneously without any sacrificial agent was prepared for the first time. Both products are high-value chemicals and in gas-liquid two phases, which avoid the trouble of separation. XRD, N2 adsorption, UV–Vis, SEM, TEM, PL, XPS and ESR were used to characterize the as-prepared catalysts. The CB and VB of as-prepared catalysts can be adjusted from −1.22 V and + 1.46 V for g-C3N4 to −0.06 V and + 2.42 V for NaCN [ 9 ] by controlling the Na+ concentration. The reaction result indicates that a moderate band position is significantly important for effective photocatalytic water splitting to simultaneously produce H2 and H2O2. After loading of Pt to promote the electron-hole separation efficiency, Pt-NaCN [ 6 ] displays the optimal H2 and H2O2 production abilities of 900 μmol·g−1·h−1 and 880 μmol·g−1, simultaneously. This work opens a new window for photocatalytic water splitting research.

Sparse representation is considered an important coding strategy for cortical processing in various sensory modalities. It remains unclear how cortical sparseness arises and is being regulated. Here, unbiased recordings from primary auditory cortex of awake adult mice revealed salient sparseness in layer (L)2/3, with a majority of excitatory neurons exhibiting no increased spiking in response to each of sound types tested. Sparse representation was not observed in parvalbumin (PV) inhibitory neurons. The nonresponding neurons did receive auditory-evoked synaptic inputs, marked by weaker excitation and lower excitation/inhibition (E/I) ratios than responding cells. Sparse representation arises during development in an experience-dependent manner, accompanied by differential changes of excitatory input strength and a transition from unimodal to bimodal distribution of E/I ratios. Sparseness level could be reduced by suppressing PV or L1 inhibitory neurons. Thus, sparse representation may be dynamically regulated via modulating E/I balance, optimizing cortical representation of the external sensory world.

Spatial size tuning in the visual cortex has been considered as an important neuronal functional property for sensory perception. However, an analogous mechanism in the auditory system has remained controversial. In the present study, cell-attached recordings in the primary auditory cortex (A1) of awake mice revealed that excitatory neurons can be categorized into three types according to their bandwidth tuning profiles in response to band-passed noise (BPN) stimuli: nonmonotonic (NM), flat, and monotonic, with the latter two considered as non-tuned for bandwidth. The prevalence of bandwidth-tuned (i.e., NM) neurons increases significantly from layer 4 to layer 2/3. With sequential cell-attached and whole-cell voltage-clamp recordings from the same neurons, we found that the bandwidth preference of excitatory neurons is largely determined by the excitatory synaptic input they receive, and that the bandwidth selectivity is further enhanced by flatly tuned inhibition observed in all cells. The latter can be attributed at least partially to the flat tuning of parvalbumin inhibitory neurons. The tuning of auditory cortical neurons for bandwidth of BPN may contribute to the processing of complex sounds.

It was the first time that phenolic resin (PR) was used as a carbon source for the synthesis of nanostructured monometallic Mo and bimetallic CoMo carbides via carbothermal reduction route. The results showed that phase-pure β-Mo2C can be formed under an Ar atmosphere at 900°C or a H2 atmosphere above 700°C. However, almost pure CoMo carbides (Co3Mo3C and Co6Mo6C) can be obtained only under a H2 atmosphere at a low temperature of 630°C for 24 and 48 h, respectively. The role of PR in the preparation process has been investigated and a detailed formation mechanism was proposed based on the experimental results.

In this study, we report a novel, simple and large-scale (about 100 g) synthesis of MoP nanoparticles with a high surface area (439.3 m2 g−1). The current approach uses a solid mixture of MoO3, (NH4)2HPO4 and phenol-formaldehyde resin (PFR) as a precursor and employs an inert gas as a feed gas. The formation mechanism of MoP was proposed by various techniques, including thermogravimetry-mass spectrometry (TG-MS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and carbon content analysis.

Cortical sensory processing is modulated by behavioral and cognitive states. How this modulation is achieved by changing synaptic circuits remains largely unknown. In awake mouse auditory cortex, we found that sensory-evoked spike responses of layer 2/3 (L2/3) excitatory cells were scaled down with preserved sensory tuning when mice transitioned from quiescence to active behaviors, including locomotion, whereas L4 and thalamic responses were unchanged. Whole-cell voltage-clamp recordings revealed that tone-evoked synaptic excitation and inhibition exhibited a robust functional balance. The change to active states caused scaling down of excitation and inhibition at approximately equal levels in L2/3 cells, but resulted in no synaptic changes in L4 cells. This lamina-specific gain control could be attributed to an enhancement of L1-mediated inhibitory tone, with L2/3 parvalbumin inhibitory neurons also being suppressed. Thus, L2/3 circuits can adjust the salience of output in accordance with momentary behavioral demands while maintaining the sensitivity and quality of sensory processing.

Summary Binaural integration in the central nucleus of inferior colliculus (ICC) plays a critical role in sound localization. However, its arithmetic nature and underlying synaptic mechanisms remain unclear. Here, we showed in mouse ICC neurons that the contralateral dominance is created by a "push-pull"-like mechanism, with contralaterally dominant excitation and more bilaterally balanced inhibition. Importantly, binaural spiking response is generated apparently from an ipsilaterally mediated scaling of contralateral response, leaving frequency tuning unchanged. This scaling effect is attributed to a divisive attenuation of contralaterally evoked synaptic excitation onto ICC neurons with their inhibition largely unaffected. Thus, a gain control mediates the linear transformation from monaural to binaural spike responses. The gain value is modulated by interaural level difference (ILD) primarily through scaling excitation to different levels. The ILD-dependent synaptic scaling and gain adjustment allow ICC neurons to dynamically encode interaural sound localization cues while maintaining an invariant representation of other independent sound attributes.

To decipher neural circuits underlying brain functions, viral tracers are widely applied to map input and output connectivity of neuronal populations. Despite the successful application of retrograde transsynaptic viruses for identifying presynaptic neurons of transduced neurons, analogous anterograde transsynaptic tools for tagging postsynaptically targeted neurons remain under development. Here, we discovered that adeno-associated viruses (AAV1 and AAV9) exhibit anterograde transsynaptic spread properties. AAV1-Cre from transduced presynaptic neurons effectively and specifically drives Cre-dependent transgene expression in selected postsynaptic neuronal targets, thus allowing axonal tracing and functional manipulations of the latter input-defined neuronal population. Its application in superior colliculus (SC) reveals that SC neuron subpopulations receiving corticocollicular projections from auditory and visual cortex specifically drive flight and freezing, two different types of defense behavior, respectively. Together with an intersectional approach, AAV-mediated anterograde transsynaptic tagging can categorize neurons by their inputs and molecular identity, and allow forward screening of distinct functional neural pathways embedded in complex brain circuits.

The origins of the deactivation of a Au/CeO2–Co3O4 catalyst during CO preferential oxidation (PROX) are investigated in detail by means of high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction of hydrogen (H2-TPR), temperature-programmed oxidation of oxygen (O2-TPO), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). A possible mechanism involving –OOH intermediate is proposed and used to explain the deactivation in the long-term stability test of CO PROX. The aggregation or sintering of the Au particles is excluded from the origins of deactivation by HRTEM and XRD. The deactivation of the catalyst is mainly due to an intrinsic transformation in the chemical state of the gold species and the support oxides in the Au/CeO2–Co3O4 catalyst. The XPS, XRD, and H2-TPR results demonstrate the reduction of ionic Au to metallic Au and of cobalt oxide to cobaltous compound. The changes of the chemical states imply a structure reordering of the catalyst surface, which will suppress the supplement of active oxygen and the formation of –OOH species, inhibit the CO oxidation reaction, and lead to the deactivation of the catalyst. The accumulation of carbonates and H2O on the deactivated catalyst is revealed by XPS, DRIFTS, O2-TPO, and a regeneration test. They are responsible for the complete deactivation of the catalyst. The hydration of the catalyst surface may play a more important role than the formation of carbonates in the deactivation of the catalyst.

The effects of carbon addition on CoMo catalyst performance for sulfidation and hydrodesulfurization (HDS) were investigated. The carbon-containing catalyst was prepared by impregnation of γ-Al2O3 support with NH3 aqueous solution containing Co(NO3)2·6H2O, (NH4)6Mo7O24·4H2O and ethylenediamine. The results indicated that the incorporation of proper carbon on CoMo catalyst can improve its HDS performance. The carbon species on the catalyst were characterized by temperature-programmed oxidation and reduction, temperature-programmed desorption of ammonia and ultraviolet-visible diffuse reflectance spectra. Two forms of carbon species were differentiated: one is spread over the catalyst surface, similar to coke formed from reaction; the other interacts with active phase as an intermediate support. The carbon species acting as intermediate support may decrease the interaction of active metals with support, which enhances the sulfidation and HDS activities of CoMo catalyst.

The stability of Pd/CeO 2 –TiO 2 catalyst for low-temperature CO oxidation in the presence of CO 2 was investigated. The effect of CO 2 lied on reaction temperature and CO 2 content. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) evidenced that the stimulative effect of CO 2 should be ascribed to the CO 2 dissociation, while the inhibited effect of CO 2 was related to the carbonate accumulation and the mechanism alternation. The coexistence of H 2 O in the feed can inhibit the carbonate accumulation, which can be employed to explain the predominant role of H 2 O positive effect in the presence of CO 2 and H 2 O together.

CO oxidation at low temperature over Pd/CeO2–TiO2 catalyst was carried out in the feed containing different contents of water vapor (H2O). A positive effect of H2O was observed on the catalytic performance of Pd/CeO2–TiO2 in CO oxidation at low temperature. The extent of this effect depends on the content of H2O in the feed; with a H2O content being 2.5 vol%, the catalyst Pd/CeO2–TiO2 exhibits the highest stability (longest life time for CO oxidation at 80 °C). The results of in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature-programmed reaction (TPReaction) reaction illustrated that H2O in the feed supplies sufficient OH groups in the presence of O2, which can react with adsorbed CO on Pd species to produce CO2. Moreover, H2O may also enhance the adsorption of CO and suppress the formation of some carbonate species.

Au/CeO2–Co3O4 catalysts with a Ce/Co atomic ratio from 0.1 to 0.6 were prepared by deposition–precipitation; their catalytic performance in preferential oxidation (PROX) of CO in H2 rich stream was investigated. Au/CeO2–Co3O4 exhibits much higher catalytic activity in CO PROX than Au/Co3O4 and Au/CeO2; over Au/CeO2–Co3O4, 100% CO conversion with 75% selectivity to CO2 can be achieved even at ambient temperature. Typically, for CO PROX at 80 °C over oxidation pretreated Au/CeO2–Co3O4 (Ce/Co = 0.2), 91% CO conversion and 51% selectivity to CO2 can last for 260 h.

Auditory evoked potential (AEP) is an effective index for the effects of general anesthetics. However, it’s unknown if AEP can differentiate the effects of general anesthetics on nerve fibers and synapses. Presently, we investigated AEP latency and amplitude changes to different acoustic intensities during pentobarbital anesthesia. Latency more regularly changed than amplitude during anesthesia. AEP Latency monotonically decreased with acoustic intensity increase (i.e., latency-intensity curve) and could be fitted to an exponential decay equation, which showed two components, the theoretical minimum latency and stimulus-dependent delay. From the latency-intensity curves, the changes of these two components (∆L and ∆I) were extracted during anesthesia. ∆L and ∆I monitored the effect of pentobarbital on nerve fibers and synapses. Pentobarbital can induce anesthesia and two side effects, hypoxemia and hypothermia. The hypoxemia was not related with ∆L and ∆I. However, ∆L was changed by the hypothermia, whereas ∆I was changed by the hypothermia and anesthesia. Therefore, we conclude that, AEP latency is superior to amplitude for the effects of general anesthetics, ∆L monitors the effect of hypothermia on nerve fibers and ∆I monitors a combined effect of anesthesia and hypothermia on synapses. When eliminating the temperature factor, ∆I monitors the anesthesia effect on synapses.

SummaryInnate defense behaviors (IDBs) evoked by threatening sensory stimuli are essential for animal survival. Although subcortical circuits are implicated in IDBs, it remains largely unclear whether sensory cortex modulates IDBs and what the underlying neural pathways are. Here, we show that optogenetic silencing of corticotectal projections from layer 5 (L5) of the mouse primary visual cortex (V1) to the superior colliculus (SC) significantly reduces an SC-dependent innate behavior (i.e., temporary suspension of locomotion upon a sudden flash of light as short as milliseconds). Surprisingly, optogenetic activation of SC-projecting neurons in V1 or their axon terminals in SC sufficiently elicits the behavior, in contrast to other major L5 corticofugal projections. Thus, via the same corticofugal projection, visual cortex not only modulates the light-induced arrest behavior, but also can directly drive the behavior. Our results suggest that sensory cortex may play a previously unrecognized role in the top-down initiation of sensory-motor behaviors.

Defense against environmental threats is essential for animal survival. However, the neural circuits responsible for transforming unconditioned sensory stimuli and generating defensive behaviours remain largely unclear. Here, we show that corticofugal neurons in the auditory cortex (ACx) targeting the inferior colliculus (IC) mediate an innate, sound-induced flight behaviour. Optogenetic activation of these neurons, or their projection terminals in the IC, is sufficient for initiating flight responses, while the inhibition of these projections reduces sound-induced flight responses. Corticocollicular axons monosynaptically innervate neurons in the cortex of the IC (ICx), and optogenetic activation of the projections from the ICx to the dorsal periaqueductal gray is sufficient for provoking flight behaviours. Our results suggest that ACx can both amplify innate acoustic-motor responses and directly drive flight behaviours in the absence of sound input through corticocollicular projections to ICx. Such corticofugal control may be a general feature of innate defense circuits across sensory modalities., Defense against environmental threats is essential for survival, yet the neural circuits mediating innate defensive behaviours are not completely understood. Here the authors demonstrate that descending projections from the auditory cortex to the midbrain mediate innate, sound-evoked flight behaviour.

To propose a new method for acquiring pulmonary function parameters based on measurement of volume changes of thoracic impedance.We studied the relationship between the volume changes of thoracic impedance and pulmonary function parameters during forced breathing based on bioimpedance measurement, and developed an instrument for measuring thoracic impedance. Using this instrument and a MRI spirolab III lung function test instrument, both based on flowmeter measurement, we measured such pulmonary function parameters including forced vital capacity (FVC), forced expiratory volume in one second/FVC (FEV1/FVC), and peak expiratory flow in 10 healthy volunteers and compared the measurement results.The differences in the parameters measured using the two instruments were all within two folds of the positive and negative standard deviations of the average values, demonstrating good consistency in the measurement between the two methods.The measurement results of the bioimpedance-based instrument we developed show good consistency with those by the commercially available pulmonary function test instrument.

A novel blood pressure measurement system was designed which based on auscultatory method. And the electret sensor that embedded into the internal instrument can detect the Korotkoff-sound signal directly which is coupled by the cuff and transmitted in the cross connection. The BP values identification algorithm is based on combined detection of Korotkoff-sound and pulse signal, and the products of amplitudes and energies are calculated as the characteristic values of Korotkoff-sound, and the Korotkoff-sound phases are classified and detected by means of clustering of characteristic values, and then BP parameters are determined. The contrast test and statistical analysis showed good consistency and accuracy between the new BP detection method and conventional mercury sphygmomanometer.

This paper is aimed to study the feasibility of myocardial infarction risk assessment by noninvasive multivariable trend analysis, including heart rate variability (HRV), deceleration capacity (DC) of heart rate and pulse wave velocity (PWV). Thirty five patients with cardiovascular diseases (11 Myocardial infarction (MI), 8 coronary artery disease (CAD), 6 artery atherosclerosis (AA) and 10 hypertension), and 31 healthy subjects were randomly selected into a control group for this research as comparison. 15 min ECG and 1 min pulse wave data were collected based on the analysis workbench developed by our Lab. HRV, DC and PWV between the cardiovascular group and the control group were analyzed and compared. The results showed that the HRV indices, DC and PWV were significantly higher than those in the control group. The DC and the HRV indices including NN50, PNN50 and TINN especially presented a decline trend that was consistent with the regularity of cardiovascular development process. This noninvasive multivariable trend analysis of HRV, DC and PWV can be a reference for the earlier risk prediction of MI.

In many sensory systems, the latency of spike responses of individual neurons is found to be tuned for stimulus features and proposed to be used as a coding strategy. Whether the spike latency tuning is simply relayed along sensory ascending pathways or generated by local circuits remains unclear. Here, in vivo whole-cell recordings from rat auditory cortical neurons in layer 4 revealed that the onset latency of their aggregate thalamic input exhibited nearly flat tuning for sound frequency, whereas their spike latency tuning was much sharper with a broadly expanded dynamic range. This suggests that the spike latency tuning is not simply inherited from the thalamus, but can be largely reconstructed by local circuits in the cortex. Dissecting of thalamocortical circuits and neural modeling further revealed that broadly tuned intracortical inhibition prolongs the integration time for spike generation preferentially at off-optimal frequencies, while sharply tuned intracortical excitation shortens it selectively at the optimal frequency. Such push and pull mechanisms mediated likely by feedforward excitatory and inhibitory inputs respectively greatly sharpen the spike latency tuning and expand its dynamic range. The modulation of integration time by thalamocortical-like circuits may represent an efficient strategy for converting information spatially coded in synaptic strength to temporal representation.

To assess mental fatigue by noninvasive monitoring of the physiological signals.The changes in the physiological parameters including the electrodermal activity, heart rate and heart rate variability were analyzed in 14 subjects performing the reaction-time tasks when fatigue and changes in the reaction time occurred.The average skin conductance level, average heart rate, and heart rate variability parameters including the total power density, percentage of the very low power density, percentage of high power density all differed significantly between the sober state and the mental fatigue state.Monitoring the physiological parameters including the electrodermal activity, heart rate and heart rate variability is a noninvasive, effective and practical approach to mental fatigue assessment.

This article describes a design of physiological signal storage format and transfer protocol for the tele-medical system between home and community. The protocol is based on ASCII character, with frames as its basic structure. There are two kinds of frames: control frames and data frames. Control frames can start and stop data transfer, confirm the order, and ask for start. There are seven kinds of data frames, according to the different data types. Data is transferred in data frames. The protocol described in this article is simple and extensible. The design target has been accomplished in real system.

The mechanisms underlying spike time coding in auditory system are not well understood. Despite of several models proposed to describe the first spike latency (FSL), there is no comparison of their respective performance. Here, based on FSL data from the central nucleus of inferior colliculus (CIC) in mouse to tone stimuli with varying rise function, rise time, and amplitude, we examined the previous models by comparing the recorded FSL with derived the FSL, respectively. We found that the LIEFTS (leaky integration, event formation, temporal summation) threshold model produced better match with the recorded data than other models. In addition, the model suggested that the short time constants derived from the FSL data (

To test the feasibility and accuracy of myocardial contrast echocardiography (MCE) for predicting infarct size (IS) in a rat model of myocardial infarction (MI) and to compare a simplified single plane-based measurement of IS with the conventional three plane-based approach. Fifty male SD rats underwent left anterior descending artery ligation and were evaluated by MCE 8 h post MI. IS was calculated by the single and three plane-based approaches, compared to that determined by triphenyltetrazolium chloride (TTC) staining method. Simplified single plane-based MCE approach and TTC method showed similar IS values (38.48 +/- 16.80% vs. 35.72 +/- 15.33%, P > 0.05) and presented a favorable positive correlation (r = 0.851, P < 0.001). IS values derived from simplified single plane-based approach was also highly significantly correlated with that by the conventional MCE method (r = 0.973, P < 0.001). Bland-Altman plots also displayed satisfactory agreement between them. MCE was validated as a novel technique to quantify infarct area in rats with MI. A single measurement at the mid-papillary muscle level may become a simple, efficient and reliable approach for in vivo IS assessment.