Spin-Phonon Coupling in Iron-Doped Ultrathin Bismuth Halide Perovskite Derivatives.

Spin in semiconductors facilitates magnetically controlled optoelectronic and spintronic devices. In metal halide perovskites (MHPs), doping magnetic ions is proven to be a simple and efficient approach to introducing a spin magnetic momentum. In this work, we present a facile metal ion doping protocol through the vapor-phase metal halide insertion reaction to the chemical vapor deposition (CVD)-grown ultrathin Cs3BiBr6 perovskites. The Fe-doped bismuth halide (Fe:CBBr) perovskites demonstrate that the iron spins are successfully incorporated into the lattice, as revealed by the spin-phonon coupling below the critical temperature Tc around 50 K observed through temperature-dependent Raman spectroscopy. Furthermore, the phonons exhibit significant softening under an applied magnetic field, possibly originating from magnetostriction and spin exchange interaction. The spin-phonon coupling in Fe:CBBr potentially provides an efficient way to tune the spin and lattice parameters for halide perovskite-based spintronics.

Toward Controlled Synthesis of 2D Crystals by CVD: Learning from the Real-Time Crystal Morphology Evolutions.

The rich morphology of 2D materials grown through chemical vapor deposition (CVD), is a distinctive feature. However, understanding the complex growth of 2D crystals under practical CVD conditions remains a challenge due to various intertwined factors. Real-time monitoring is crucial to providing essential data and enabling the use of advanced tools like machine learning for unraveling these complexities. In this study, we present a custom-built miniaturized CVD system capable of observing and recording 2D MoS2 crystal growth in real time. Image processing converts the real-time footage into digital data, and machine learning algorithms (ML) unveil the significant factors influencing growth. The machine learning model successfully predicts CVD growth parameters for synthesizing ultralarge monolayer MoS2 crystals. It also demonstrates the potential to reverse engineer CVD growth parameters by analyzing the as-grown 2D crystal morphology. This interdisciplinary approach can be integrated to enhance our understanding of controlled 2D crystal synthesis through CVD.

Risk assessment of pesticide compounds: IPT and TCZ cause hepatotoxicity, activate stress pathway and affect the composition of intestinal flora in red swamp crayfish (Procambarusclarkii).

Isoprothiolane (IPT) and tricyclazole (TCZ) are widely used in rice farming and recently in combined rice-fish farming. However, co-cultured animals are affected by these pesticides. To investigate the organismal effects and toxicity of pesticides, crayfish were exposed to 0, 1, 10, or 100 ppt TCZ or IPT for 7 days. Pesticide bioaccumulation, survival rate, metabolic parameters, structure of intestinal flora, and antioxidant-, apoptosis-, and HSP-related gene expression were determined. Pesticide exposure caused bioaccumulation of IPT or TCZ in the hepatopancreas and muscles of crayfish; however, IPT bioaccumulation was higher than that of TCZ. Both groups showed significant changes in hepatopancreatic serum biochemical parameters. Mitochondrial damage and chromosomal agglutination were observed in hepatopancreatic cells exposed to 100 ppt IPT or TCZ. IPT induced more significant changes in serum biochemical parameters than TCZ. The results of intestinal flora showed that Vibro, Flavobacterium, Anaerorhabdus and Shewanella may have potential for use as a bacterial marker of TCZ and IPT. Antioxidant-, apoptosis-, and HSP-related gene expression was disrupted by pesticide exposure, and was more seriously affected by IPT. The results suggest that IPT or TCZ induce hepatopancreatic cell toxicity; however, IPT or TCZ content in dietary crayfish exposed to 1 ppt was below the food safety residue standard. The data indicated that IPT exposure may be more toxic than TCZ exposure in hepatopancreas and intestines and toxicity of organism are alleviated by activating the pathway of stress-response, providing an understanding of pesticide compounds in rice-fish farming and food safety.

Structural and functional analysis of transforming growth factor beta regulator 1 (TBRG1) in the red swamp crayfish Procambarus clarkii: The initial insight into TBRG1's role in invertebrate immunity.

The transforming growth factor beta regulator 1 (TBRG1) is a growth inhibitory protein that acts as a tumor suppressor in human cancers, gaining its name for the transcriptional regulation by TGF-ß. While extensive research has been conducted on the tumor-related function of TBRG1 in mammals, its significance in invertebrates remains largely unexplored. In this study, a homolog of TBRG1 was first structurally and functionally analyzed in the red swamp crayfish Procambarus clarkii. The full-length cDNA sequence was 2143 base pairs (bp) with a 1305 bp open reading frame (ORF) encoding a deduced protein of 434 amino acids (aa). The changes of PcTBRG1 transcripts upon immune challenges indicated its involvement in innate immunity. After knocking down PcTBRG1, the decline of bacteria clearance capacity revealed the participation of PcTBRG1 in the immune response. Furthermore, the downregulation of AMPs' expression after the cotreatment of RNAi and bacteria challenge suggested that PcTBRG1 might participate in innate immunity through regulating AMPs' expression. These results provided initial insight into the immune-related function of TBRG1 in invertebrates.

The first identification and functional analysis of two drosophila mothers against decapentaplegic protein genes (SpSmad1 and SpSmad2/3) and their involvement in the innate immune response in Scylla paramamosain.

Smad，a member of the TGF-ß superfamily，controls cell proliferation，growth and guiding cell differentiation, thus playing a crucial role in diseases. However, the presence as well as specific function of Smad in crabs is still unknown. In this study, two Smads (Smad1 and Smad2/3) were identified for the first time from the mud crab Scylla paramamosain. The complete open reading frames of SpSmad1 and SpSmad2/3 were 1,497bp and 1,338bp, encoding deduced proteins of 498 and 445 amino acids respectively. Moreover, under the administration of Vibrio alginolyticus and WSSV, the relative expression levels of SpSmad1 and SpSmad2/3 were significantly increased, indicating their involvement in the innate immune response of mud crabs. Knockdown of SpSmad1 and SpSmad2/3 in vivo not only led to the increasement of the expressions of NF-κB signaling genes and antimicrobial peptides genes, but also significantly affected the bacterial clearance process of mud crabs. Additionally, overexpression of SpSmad1 and SpSmad2/3 in HEK293T cells could markedly activate NF-κB signaling. These results indicated that Smad1 and Smad2/3 participated in the innate immunity of Scylla paramamosain, and might provide a better understanding of the presence and immune regulatory functions of Smad1 and Smad2/3 in crabs and even invertebrates.

Identification and functional analysis of endoplasmic reticulum oxidoreductase 1 (ERO1) from the green mud crab Scylla paramamosain: The first evidence of ERO1 involved in invertebrate immune response.

Endoplasmic reticulum oxidoreductase 1 (ERO1) is an important mediator in regulating disulfide bond formation and maintaining endoplasmic reticulum homeostasis. Its activity is transcriptionally regulated by the unfolded protein response (UPR) in the endoplasmic reticulum, which is known to be essential in immunity. However, whether ERO1 is involved in innate immunity in invertebrates remains unclear. In the present study, two subtypes of ERO1 from Scylla paramamosain were first identified and characterized. Sequence analysis revealed the conserved ERO1 domain and the oxidative capacity assay verified the oxidative capacity of SpERO1 recombinant protein. Moreover, SpERO1s were found to be ubiquitously expressed in all the tested tissues, with the highest expression observed in hemocytes. Two SpERO1s exhibited distinct expression patterns in response to Vibrio alginolyticus and White Spot Syndrome Virus (WSSV). Importantly, the downregulation of the expression of immune factors upon bacterial challenge in SpERO1-silenced crabs was observed. These results provided an initial foundation for further investigations into the role of ERO1 in the innate immunity of invertebrates.

Identification and functional analysis of cytosolic phospholipase A2 (cPLA2) from the red swamp crayfish Procambarus clarkii: The first evidence of cPLA2 involved in immunity in invertebrates.

Cytosolic phospholipase A2 (cPLA2) specifically liberates the arachidonic acids from the phospholipid substrates. In mammals, cPLA2 serves as a key control point in inflammatory responses due to its diverse downstream products. However, the role of cPLA2 in animals lower than mammals largely remains unknown. In the current research, a homolog of cPLA2 was first identified and characterized in the red swamp crayfish Procambarus clarkii. The full-length cDNA of PccPLA2 was 4432 bp in length with a 3036 bp-long open reading frame, encoding a putative protein of 1011 amino acids that contained a protein kinase C conserved region 2 and a catalytic subunit of cPLA2. PccPLA2 was ubiquitously expressed in all examined tissues with the highest expression in the hepatopancreas, and the expression in hemocytes as well as hepatopancreas was induced upon the immune challenges of WSSV and Aeromonas hydrophila. After the co-treatment of RNA interference and bacterial infection, the decline of bacteria clearance capability was observed in the hemolymph, and the expression of some antimicrobial peptides (AMPs) was significantly suppressed. Additionally, the phagocytosis of A. hydrophila by primary hemocytes decreased when treated with the specific inhibitor CAY10650 of cPLA2. These results indicated the participation of PccPLA2 in both cellular and humoral immune responses in the crayfish, which provided an insight into the role that cPLA2 played in the innate immunity of crustaceans, and even in invertebrates.

Identification and characterization of mitogen-activated protein kinase kinase 4 (MKK4) from the mud crab Scylla paramamosain in response to Vibrio alginolyticus and White Spot Syndrome Virus (WSSV).

Mitogen-activated protein kinase kinase 4 (MKK4), serves as a critical component of the mitogen-activated protein kinase signaling pathway, facilitating the direct phosphorylation and activation of the c-Jun N-terminal kinase (JNK) and p38 families of MAP kinases in response to environmental stresses. In the current research, we identified two MKK4 subtypes, namely SpMKK4-1 and SpMKK4-2, from Scylla paramamosain, followed by the analysis of their molecular characteristics and tissue distributions. The expression of SpMKK4s was induced upon WSSV and Vibrio alginolyticus challenges, and the bacteria clearance capacity and antimicrobial peptide (AMP) genes' expression upon bacterial infection were significantly decreased after knocking down SpMKK4s. Additionally, the overexpression of both SpMKK4s remarkably activated NF-κB reporter plasmid in HEK293T cells, suggesting the activation of the NF-κB signaling pathway. These results indicated the participation of SpMKK4s in the innate immunity of crabs, which shed light on a better understanding of the mechanisms through which MKK4s regulate innate immunity.

Selenium alleviates biological toxicity of thiamethoxam (TMX): Bioaccumulation of TMX, organ damage, and antioxidant response of red swamp crayfish (Procambarus clarkii).

Pesticides are important for agricultural development; however, animals involved in rice-fish farming absorb the pesticides used during the farming process. Thiamethoxam (TMX) is extensively used in agriculture and is gradually occupying the market for traditional pesticides. Therefore, this study aimed to investigate whether selenomethionine (SeMet) could affect the survival rate, bioaccumulation of TMX, serum biochemical parameters, lipid peroxidation, antioxidants in the hepatopancreas, and expression of stress genes after exposure of red swamp crayfish to 10 ppt TMX for 7 days. The results showed that the survival rate significantly increased and the bioaccumulation of TMX significantly decreased with SeMet administration (P < 0.05). Furthermore, severe histological damage to the hepatopancreas of red crayfish was observed after exposure to TMX; however, this damage was alleviated after SeMet administration. SeMet also significantly reduced the TMX-induced changes in serum biochemical parameters, malondialdehyde content, and antioxidant enzyme activity in crayfish hepatopancreas (P < 0.05). Notably, analysis of the expression of 10 stress response genes showed that 0.5 mg/kg SeMet might decrease cell damage in the hepatopancreas. Consequently, our findings suggest that higher levels of TMX in crayfish may cause hepatopancreatic cell toxicity, which can be harmful to human health; however, SeMet could mitigate these effects, providing an understanding of pesticide compounds and food safety.

Effects of low salinity stress on osmoregulation and gill transcriptome in different populations of mud crab Scylla paramamosain.

Animals living in estuaries suffer from rapid and continuous salinity fluctuations, while the global warming and extreme precipitation aggravate this situation. Osmoregulation is important for estuarine animals adapt to salinity fluctuations. The present study investigated the effects of low salinity stress on osmoregulation and gill transcriptome in two populations of mud crab from Hangzhou Bay and Zhangzhou Bay of China, respectively. Crabs were transferred from salinity 25 ppt to 5 ppt for 96 h. Edematous swelling in gill filaments was caused by low salinity stress and was more serious in Zhangzhou Bay population. Gill Na+/K+-ATPase activity increased (p < 0.01) in both populations under the low salinity stress and was significantly higher (p < 0.01) in Hangzhou Bay population than in Zhangzhou Bay population. According to transcriptome analysis, there were 191 genes differentially expressed under the low salinity stress in gill tissue of both populations. Several ion transport and energy metabolism related pathways, as well as the arginine and proline metabolism pathway, were enriched by these genes. On the other hand, 272 genes were identified to differentially express between two populations under the low salinity stress, but not under the control salinity. The enrichment analysis showed that these genes were mainly related to ion transport, energy metabolism, osmolytes metabolism and methyltransferase activity. In conclusion, the present study suggested that mud crab exploited a combination of extracellular anisosmotic regulation and intracellular isosmotic regulation for osmoregulation under the low salinity stress. Hangzhou Bay population showed a greater osmoregulatory capacity, which is probably due to the enhanced ion transport, energy supply, and osmolytes regulation. Meanwhile, epigenetic modification might also contribute to an inherent osmoregulation ability for Hangzhou Bay population to response to salinity fluctuation rapidly.

Characterization of fibroblast growth factor receptor 4 (FGFR4) from the red swamp crayfish Procambarus clarkii and its role in antiviral and antimicrobial immune responses.

FGFRs involved multiple physiological processes, such as endocrine homeostasis, wound repair, and cellular behaviors including proliferation, differentiation and survival. In the present study, the homologs of fibroblast growth factor receptor 4 (FGFR4) were identified and characterized from the red swamp crayfish Procambarus clarkii for the first time. The full-length cDNAs of pcFGFR4 were 2878 bp with 2451 bp open reading frame (ORF), respectively. The deduced pcFGFR4 protein contained an immunoglobulin, two immunoglobulin C-2 Type, a transmembrane region and a catalytic domain. Real-time PCR analysis showed that pcFGFR4 were highly expressed in muscle and hemocyte. Moreover, the expression levels of pcFGFR4 in the hepatopancreas and hemocyte were positively stimulated after challenge with Aeromonas hydrophila and WSSV, implying the involvement of pcFGFR4 against bacterial and viral infections in innate immune responses. While pcFGFR4 were silenced in vivo, the expression levels of antimicrobial peptide (AMP) genes (pcALF1-5,8 and pcCrustin1-2) and NF-κB signaling components (pcDrosal and pcRelish) were significantly reduced. Additionally, NF-κB signaling could be markedly activated by overexpression of pcFGFR4 in HEK293T cells. Finally, our results indicated that pcFGFR4 regulated crayfish's innate immunity by modulating NF-κB signaling. These findings may provide new insights into pcFGFR4-mediated signaling cascades in crustaceans and provide a better understanding of crustacean innate immune system.

The first identification of three AdIRAK2 genes from an evolutionarily important amphibian Andrias davidianus and their involvement in NF-κB activation and inflammatory responses.

Interleukin-1 receptor associated kinases (IRAK) is the most important downstream kinases of TLRs/IL-1R signaling pathway for signal transduction and activation of inflammatory response against pathogen infections. However, the molecular identification and function characterization of IRAK2 homologs in lower vertebrate remains obscure. In this study, three IRAK2 genes (AdIRAK2a, AdIRAKb and AdIRAK2c) and their respective transcripts were identified from the Chinese giant salamander Andrias davidianus. This is the first evidence that three different IRAK2 genes exist in an ancient amphibian species, which has never been reported in other vertebrates. The complete open reading frames (ORFs) of AdIRAK2a, AdIRAK2b and AdIRAK2c were 2112 bp, 1917 bp and 816 bp encoding deduced proteins of 703 amino acids (aa), 628 aa and 271 aa, respectively. All three AdIRAK2 proteins contained two predicted conserved functional domains, including a death domain (DD) and a serine/threonine protein kinases domain (KD). Phylogenetic analysis showed that the three AdIRAK2s clustered together with other known IRAK2 of vertebrates. The three AdIRAK2s were ubiquitously expressed in all tested tissues with a similar tissues distribution pattern. After challenge of Aeromonas hydrophila (A. hydrophila), Staphylococcus aureus (S.aureus), giant salamander iridovirus (GSIV, belonging to the genus Ranavirus in the family Iridoviridae) and polyinosinic:polycytidylic acid (poly(I:C)), the expression levels of all AdIRAK2s in blood were significantly altered, however, they exhibited distinct response patterns. Moreover, the results of over-expression and RNAi of AdIRAK2s implied the involvement of AdIRAK2s in triggering NF-κB-mediated signaling pathways and inflammatory responses. This study might provide a better understanding of the presence and immune regulation function of IRAK2 in amphibians and even in vertebrates.

Bioaccumulation of Cd and comparative transcriptome analysis after the antagonism of Se in the hepatopancreas of estuary mud crab (Scylla paramamosain).

Cadmium (Cd) is a heavy metal contaminant and can be toxic to environment. What's more, Selenium (Se) protects organism as heavy metal antagonist. The present study aimed to investigate whether inorganic (Na2SeO3) or organic (L-SeMc) Se have an effect on the Cd bioaccumulation, antioxidant and immunity of the mud crab (Scylla paramamosain) under Cd exposure. The study showed that the concentration of Cd in hepatopancreas under Cd exposure was higher than the inorganic or organic Se group (P < 0.05), notably, Cd concentration of hepatopancreas in organic Se treatment is less than that in inorganic Se treatment (P < 0.05). Furthermore, this study analyzed 28 gene expression about antioxidant and immune from transcriptome, the result indicated that L-SeMc (organic Se) can reduced intracellular ROS production and oxidative damage. Furthermore, apoptosis was enhanced after Cd exposure, but Se could protect against apoptosis via expression of cathepsin B. Consequently, Organic Se may have a better effect than inorganic Se on reducing Cd toxicity. This study could provide the molecular basis that Se might alleviate Cd toxicity and increases the understanding of the environmental contaminant on crustaceans.

Identification and functional analysis of two drosophila mothers against decapentaplegic protein(Smad)genes and their involvement in immune responses in the red swamp crayfish Procambarus clarkii.

Drosophila mothers against decapentaplegic proteins (Smads), the crucial signal transducers in activating downstream gene transcription through transforming growth factor beta (TGF-ß) receptors, are the pleiotropic factors with important role in mediating cell proliferation, homeostasis, differentiation, apoptosis and immune response. However, whether Smads are involved in immune response in crustaceans remains unexplored. In the present study, the Smad3 and Smad4 were firstly identified and functionally characterized from the Red Swamp Crayfish Procambarus clarkii. The full-length cDNAs of pcSmad3 and pcSmad4 were 1, 670 bp and 3, 060 bp with 1, 326 bp and 1, 875 bp open reading frame (ORF), respectively. Real-time PCR analysis of the expression profiles demonstrated that pcSmad3 and pcSmad4 were predominantly expressed at in stomach, heart, and hemocytes. Notably, the expression levels of pcSmad3 and pcSmad4 both Aeromonas hydrophila and WSSV challenges were significantly altered, suggesting the involvement of pcSmad3 and pcSmad4 in innate immune responses. Knockdown of pcSmad3 and pcSmad4 in vivo dramatically activated the transcriptions of NF-κB signaling genes and anti-lipopolysaccharide factor genes. The overexpression of pcSmad3 and pcSmad4 could significantly activate NF-κB signaling in HEK293T cells. Meanwhile, the clearance of bacteria was significantly reduced with knockdown of pcSmad3 and pcSmad4 in vivo. Results indicated that pcSmad3 and pcSmad4 played an immune-regulatory role in crayfish's innate immunity, which might pave the for a better understanding of the TGF-ß superfamily members in crustacean.

The health risk for consumers under heavy metal scenarios: Reduce bioaccumulation of Cd in estuary mud crab (Scylla paramamosain) through the antagonism of Se.

Heavy metal pollution has gained increasing attention over past years, and notably, cadmium (Cd) is a non-essential heavy metal that can be toxic to human and wildlife. Furthermore, selenium (Se) is a component of the selenoproteins and influences the toxicity of Cd in different organisms, and protect organisms as a kind of heavy metal antagonist. This study exposed mud crab to 5.0 mg/L Cd for 28 days, and investigated whether different concentrations (0.1, 0.2, 0.3 mg/kg) of selenite (Na2SeO3) or selenomethionine (SeMet) affect the bioaccumulation of Cd, serum biochemical index, antioxidant and stress-response genes of S. paramamosain. The results showed that the Cd concentration in Cd group was significantly higher than the organic or inorganic Se group. Serum biochemical index demonstrated that Se might relieve the damage or dysfunction of hepatopancreas caused by both Cd accumulation and toxicity. Furthermore, Se improved CAT, GPx T-AOC and SOD activity, and decreased MDA concentrations and the lipid peroxidation levels, antagonistic to Cd. Then, this study analyzed the expression of 26 stress-related genes, the results indicated that the inorganic and organic Se might reduce the damage of cell and the toxicity of heavy metals in the hepatopancreas after Cd exposure. Therefore, this study indicated that Se might alleviate Cd toxicity via the different antioxidative mechanisms, and increased the understanding of environmental toxins on estuary crustaceans.

Identification and functional analysis of drosophila mothers against decapentaplegic protein gene 1 (Smad1) from the red swamp crayfish Procambarus clarkii: The first evidence of Smad1 involved in immunity in invertebrates.

Smads, part of signaling cascades that represent downstream pathways of the TGF-ß super family proteins, are pleiotropic cytokines with important role in mediating cell proliferation, homeostasis, differentiation, apoptosis and immune response. However, the specific functions of Smads remain unknown in crustaceans. In the present study, the drosophila mothers against decapentaplegic protein gene 1 (Smad1) was firstly identified and characterized from the Red Swamp Crayfish Procambarus clarkii. The obtained cDNA sequence of pcSmad1was 2, 503 bp long with a 1, 488 bp open reading fame, which encoded a putative protein of 496 amino acids. Furthermore, pcSmad1 responded to both Aeromonas hydrophila and WSSV challenge, suggesting the involvement of pcSmad1 in innate immune responses. Knockdown of pcSmad1 in vivo dramatically increased the expressions of NF-κB signaling genes and anti-lipopolysaccharide factor genes. Additionally, overexpression of pcSmad1 in HEK293T cells could markedly activate NF-κB signaling. Taken together, these results indicated that pcSmad1 played an immune-regulatory role in crayfish's innate immunity, which may provide a better understanding of TGF-ß superfamily members in crustacean.

Effects of air exposure stress on crustaceans: Histopathological changes, antioxidant and immunity of the red swamp crayfish Procambarus clarkii.

Air exposure stress may result in oxidative damage and ultimately disease or death in crustaceans. Using the Procambarus clarkia, one of the main commercial aquaculture species in China, as a study model, the molecular mechanism including histopathological changes, antioxidant capacity and immunity response under the air exposure stress were firstly evaluated. Results showed that the surfaces of gill were wrinkled while the morphologies of the nuclei and mitochondria in the hepatopancreas were altered after 48 h of air exposure stress, and the damage of mitochondria was more serious after additional bacterial infection. Moreover, the activity of antioxidant enzymes increased at first and then decreased along with increasement of air exposure time. The concentration of malondialdehyde (MDA) in hepatopancreas was significantly increased under the air exposure stress, while the bacterial infection further aggravated such oxidative damage. The transcriptome analysis exhibited that the stress- and immunity-related genes in hepatopancreas altered when response to the air exposure stress. This study could help uncover the mechanisms of aerial exposure stress responses in Procambarus clarkii.

Poincaré plot analysis of autocorrelation function of RR intervals in patients with acute myocardial infarction.

The Poincaré plot of RR intervals (RRI) is obtained by plotting RRIn+1 against RRIn. The Pearson correlation coefficient (ρRRI), slope (SRRI), Y-intercept (YRRI), standard deviation of instantaneous beat-to-beat RRI variability (SD1RR), and standard deviation of continuous long-term RRI variability (SD2RR) can be defined to characterize the plot. Similarly, the Poincaré plot of autocorrelation function (ACF) of RRI can be obtained by plotting ACFk+1 against ACFk. The corresponding Pearson correlation coefficient (ρACF), slope (SACF), Y-intercept (YACF), SD1ACF, and SD2ACF can be defined similarly to characterize the plot. By comparing the indices of Poincaré plots of RRI and ACF between patients with acute myocardial infarction (AMI) and patients with patent coronary artery (PCA), we found that the ρACF and SACF were significantly larger, whereas the RMSSDACF/SDACF and SD1ACF/SD2ACF were significantly smaller in AMI patients. The ρACF and SACF correlated significantly and negatively with normalized high-frequency power (nHFP), and significantly and positively with normalized very low-frequency power (nVLFP) of heart rate variability in both groups of patients. On the contrary, the RMSSDACF/SDACF and SD1ACF/SD2ACF correlated significantly and positively with nHFP, and significantly and negatively with nVLFP and low-/high-frequency power ratio (LHR) in both groups of patients. We concluded that the ρACF, SACF, RMSSDACF/SDACF, and SD1ACF/SD2ACF, among many other indices of ACF Poincaré plot, can be used to differentiate between patients with AMI and patients with PCA, and that the increase in ρACF and SACF and the decrease in RMSSDACF/SDACF and SD1ACF/SD2ACF suggest an increased sympathetic and decreased vagal modulations in both groups of patients.