COP1 controls light-dependent chromatin remodeling.

Light is a crucial environmental factor that impacts various aspects of plant development. Phytochromes, as light sensors, regulate myriads of downstream genes to mediate developmental reprogramming in response to changes in environmental conditions. CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) is an E3 ligase for a number of substrates in light signaling, acting as a central repressor of photomorphogenesis. The interplay between phytochrome B (phyB) and COP1 forms an antagonistic regulatory module that triggers extensive gene expression reprogramming when exposed to light. Here, we uncover a role of COP1 in light-dependent chromatin remodeling through the regulation of VIL1 (VIN3-LIKE 1)/VERNALIZATION 5, a Polycomb protein. VIL1 directly interacts with phyB and regulates photomorphogenesis through the formation of repressive chromatin loops at downstream growth-promoting genes in response to light. Furthermore, we reveal that COP1 governs light-dependent formation of chromatin loop and limiting a repressive histone modification to fine-tune expressions of growth-promoting genes during photomorphogenesis through VIL1.

MYB transcription factors encoded by diversified tandem gene clusters cause varied Morella rubra fruit color.

Chinese bayberry (Morella rubra) is a fruit tree with a remarkable variation in fruit color, ranging from white to dark red as determined by anthocyanin content. In dark red "Biqi" (BQ), red "Dongkui" (DK), pink "Fenhong" (FH), and white "Shuijing" (SJ), we identified an anthocyanin-related MYB transcription factor-encoding gene cluster of four members, i.e. MrMYB1.1, MrMYB1.2, MrMYB1.3, and MrMYB2. Collinear analysis revealed that the MYB tandem cluster may have occurred in a highly conserved region of many eudicot genomes. Two alleles of MrMYB1.1 were observed; MrMYB1.1-1 (MrMYB1.1n) was a full-length allele and homozygous in "BQ", MrMYB1.1-2 (MrMYB1.1d) was a nonfunctional allele with a single base deletion and homozygous in "SJ", and MrMYB1.1n/MrMYB1.1d were heterozygous in "DK" and "FH". In these four cultivars, expression of MrMYB1.1, MrMYB1.2, and MrMYB2 was enhanced during ripening. Both alleles were equally expressed in MrMYB1.1n/MrMYB1.1d heterozygous cultivars as revealed by a cleaved amplified polymorphic sequence marker. Expression of MrMYB1.3 was restricted to some dark red cultivars only. Functional characterization revealed that MrMYB1.1n and MrMYB1.3 can induce anthocyanin accumulation while MrMYB1.1d, MrMYB1.2, and MrMYB2 cannot. DNA-protein interaction assays indicated that MrMYB1.1n and MrMYB1.3 can directly bind to and activate the promoters of anthocyanin-related genes via interaction with a MYC-like basic helix-loop-helix protein MrbHLH1. We concluded that the specific genotype of MrMYB1.1 alleles, as well as the exclusive expression of MrMYB1.3 in some dark red cultivars, contributes to fruit color variation. The study provides insights into the mechanisms for regulation of plant anthocyanin accumulation by MYB tandem clusters.

Heat-Assisted Magnetization Switching in Flexible Spin-Orbit Torque Devices.

Heat-assisted magnetic anisotropy engineering has been successfully used in selective magnetic writing and microwave amplification due to a large interfacial thermal resistance between the MgO barrier and the adjacent ferromagnetic layers. However, in spin-orbit torque devices, the writing current does not flow through the tunnel barrier, resulting in a negligible heating effect due to efficient heat dissipation. Here, we report a dramatically reduced switching current density of ∼2.59 MA/cm2 in flexible spin-orbit torque heterostructures, indicating a 98% decrease in writing energy consumption compared with that on a silicon substrate. The reduced driving current density is enabled by the dramatically decreased magnetic anisotropy due to Joule dissipation and the lower thermal conductivity of the flexible substrate. The large magnetic anisotropy could be fully recovered after the impulse, indicating retained high stability. These results pave the way for flexible spintronics with the otherwise incompatible advantages of low power consumption and high stability.

Identification of important genes related to anoikis in acute myocardial infarction.

Acute myocardial infarction (AMI) increasingly precipitates severe heart failure, with diagnoses now extending to progressively younger demographics. The focus of this study was to pinpoint critical genes linked to both AMI and anoikis, thereby unveiling potential novel biomarkers for AMI detection and intervention. Differential analysis was performed to identify significant differences in expression, and gene functionality was explored. Weighted gene coexpression network analysis (WGCNA) was used to construct gene coexpression networks. Immunoinfiltration analysis quantified immune cell abundance. Protein-protein interaction (PPI) analysis identified the proteins that interact with theanoikis. MCODE identified key functional modules. Drug enrichment analysis identified relevant compounds explored in the DsigDB. Through WGCNA, 13 key genes associated with anoikis and differentially expressed genes were identified. GO and KEGG pathway enrichment revealed the regulation of apoptotic signalling pathways and negative regulation of anoikis. PPI network analysis was also conducted, and 10 hub genes, such as IL1B, ZAP70, LCK, FASLG, CD4, LRP1, CDH2, MERTK, APOE and VTN were identified. IL1B were correlated with macrophages, mast cells, neutrophils and Tcells in MI, and the most common predicted medications were roxithromycin, NSC267099 and alsterpaullone. This study identified key genes associated with AMI and anoikis, highlighting their role in immune infiltration, diagnosis and medication prediction. These findings provide valuable insights into potential biomarkers and therapeutic targets for AMI.

Inferior social hierarchy is vulnerable to anxiety-like behavior in chronic pain mice: Potential role of gut microbiota and metabolites.

Social dominance is a universal phenomenon among grouped animals that profoundly affects survival, health, and reproductive success by determining access to resources, and exerting a powerful influence on subsequent behavior. However, the understanding of pain and anxiety comorbidities in dominant or subordinate animals suffering from chronic pain is not well-defined. Here, we provide evidence that subordinate mice are more susceptible to pain-induced anxiety compared to dominant mice. We propose that the gut microbiota may play a mediating role in this mechanism. Our findings demonstrate that transplantation of fecal microbiota from subordinate mice with chronic inflammatory pain, but not dominant mice, into antibiotics-treated pseudo-germ-free mice significantly amplifies anxiety-like phenotypes, highlighting the critical involvement of gut microbiota in this behavioral response. Using chronic inflammatory pain model, we carried out 16S rRNA sequencing and untargeted metabolomic analyses to explore the relationship between microbiota and metabolites in a stable social hierarchy of mice. Interestingly, anxiety-like behaviors were directly associated with some microbial genera and metabolites, especially bile acid metabolism. Overall, we have demonstrated a close relationship between social status and anxiety susceptibility, highlighting the contributions of gut microbiota and the associated metabolites in the high-anxiety state of subordinate mice with chronic inflammatory pain.

Chromatin sensing: Integration of environmental signals to reprogram plant development through chromatin regulators.

Chromatin regulation in eukaryotes plays pivotal roles in controlling developmental regulatory gene network. This review explores the intricate interplay between chromatin regulators and environmental signals, elucidating their roles in shaping plant development. As sessile organisms, plants have evolved sophisticated mechanisms to perceive and respond to environmental cues, orchestrating developmental programs that ensure adaptability and survival. A central aspect of this dynamic response lies in the modulation of versatile gene regulatory networks, mediated in part by various chromatin regulators. Here, we summarized the current understanding of the molecular mechanisms through which chromatin regulators integrate environmental signals, influencing key aspects of plant development.

Lanthanide/B(C6F5)3-Promoted Hydroboration Reduction of Indoles and Quinolines with Pinacolborane.

We have developed a lanthanide/B(C6F5)3-promoted hydroboration reduction of indoles and quinolines with pinacolborane (HBpin). This reaction provides streamlined access to a range of nitrogen-containing compounds in moderate to excellent yields. Large-scale synthesis and further transformations to bioactive compounds indicate that the method has potential practical applications. Preliminary mechanistic studies suggest that amine additives promote the formation of indole-borane intermediates, and the lanthanide/B(C6F5)3-promoted hydroboration reduction proceeds via hydroboration of indole-borane intermediates with HBpin and in situ-formed BH3 species, followed by the protodeborylation process.

Cobalt-Catalyzed Borylative Reduction of Azobenzenes to Hydrazobenzenes via a Diborylated-Hydrazine Intermediate.

Cobalt-catalyzed borylative reduction of azobenzenes using pinacolborane is developed. The simple cobalt chloride catalyst and reaction conditions make this protocol attractive for hydrazobenzene synthesis. This borylative reduction shows good functional group compatibility and can be readily scaled up to the gram scale. Preliminary mechanistic studies clarified the proton source of the hydrazine products. This cobalt-catalyzed azobenzene borylative reaction provides a practical protocol to prepare synthetically useful diborylated hydrazines.

Obstetric blood transfusion in placenta previa patients with prenatal anemia: a retrospective study.

BACKGROUND: The appropriate use of obstetric blood transfusion is crucial for patients with placenta previa and prenatal anemia. This retrospective study aims to explore the correlation between prenatal anemia and blood transfusion-related parameters in this population. METHODS: We retrieved the medical records of consecutive participants who were diagnosed with placenta previa and underwent cesarean section in our hospital. We compared the baseline demographics and clinical characteristics of patients with and without anemia. The correlation between prenatal anemia and obstetric blood transfusion-related parameters was evaluated using multivariate regression analysis. RESULTS: A total of 749 patients were enrolled, with a mean prenatal hemoglobin level of 10.87 ± 1.37 g/dL. Among them, 54.87% (391/749) were diagnosed with anemia. The rate of obstetric blood transfusion was significantly higher in the anemia group (79.54%) compared to the normal group (44.41%). The median allogeneic red blood cell transfusion volume in the anemia group was 4.00 U (IQR 2.00-6.00), while in the normal group, it was 0.00 U (IQR 0.00-4.00). The prenatal hemoglobin levels had a non-linear relationship with intraoperative allogeneic blood transfusion rate, massive blood transfusion rate, red blood cell transfusion units, and fresh plasma transfusion volume in patients with placenta previa, with a threshold of 12 g/dL. CONCLUSIONS: Our findings suggest that prenatal anemia is associated with a higher rate of blood transfusion-related parameters in women with placenta previa when the hemoglobin level is < 12 g/dL. These results highlight the importance of promoting prenatal care in placenta previa patients with a high requirement for blood transfusion.

Lactoferrin deficiency during lactation increases the risk of depressive-like behavior in adult mice.

BACKGROUND: Lactoferrin is an active protein in breast milk that plays an important role in the growth and development of infants and is implicated as a neuroprotective agent. The incidence of depression is currently increasing, and it is unclear whether the lack of lactoferrin during lactation affects the incidence of depressive-like behavior in adulthood. RESULTS: Lack of lactoferrin feeding during lactation affected the barrier and innate immune functions of the intestine, disrupted the intestinal microflora, and led to neuroimmune dysfunction and neurodevelopmental delay in the hippocampus. When exposed to external stimulation, adult lactoferrin feeding-deficient mice presented with worse depression-like symptoms; the mechanisms involved were activation of the LPS-TLR4 signalling pathway in the intestine and hippocampus, reduced BDNF-CREB signaling pathway in hippocampus, increased abundance of depression-related bacteria, and decreased abundance of beneficial bacteria. CONCLUSIONS: Overall, our findings reveal that lactoferrin feeding deficient during lactation can increase the risk of depressive-like behavior in adults. The mechanism is related to the regulatory effect of lactoferrin on the development of the "microbial-intestinal-brain" axis.

QTL Mapping of Adult Plant Resistance to Powdery Mildew in Chinese Wheat Landrace Baidatou.

Wheat powdery mildew, caused by the biotrophic fungus Blumeria graminis f. sp. tritici (Bgt), is one of the most devastating diseases affecting wheat throughout the world. Breeding and growing resistant wheat cultivars is one of the most economic and effective methods to control the disease, and as such, identifying and mapping the new and effective resistance genes is critical. Baidatou, a Chinese wheat landrace, shows excellent field resistance to powdery mildew. To identify the resistance gene(s) in Baidatou, 170 F7:8 recombinant inbred lines (RILs) derived from the cross Mingxian 169/Baidatou were evaluated for powdery mildew response at the adult-plant stage in the experimental fields in Yangling (YL) of Shaanxi Province and Tianshui (TS) in Gansu Province in 2019, 2020, and 2021. The relative area under disease progress curve (rAUDPC) of Mingxian 169/Baidatou F7:8 RILs indicated that the resistance of Baidatou to powdery mildew was controlled by quantitative trait loci (QTLs). Based on bulk segregation analysis combined with the 660K single nucleotide polymorphism (SNP) array and genotyping by target sequencing (16K SNP) of the entire RIL population, two QTLs, QPmbdt.nwafu-2AS and QPmbdt.nwafu-3AS, were identified, and these accounted for up to 44.5% of the phenotypic variation. One of the QTLs was located on the 3.32 cM genetic interval on wheat chromosome 2AS between the kompetitive allele-specific PCR markers AX-111012288 and AX_174233809, and another was located on the 9.6 cM genetic interval on chromosome 3AS between the SNP markers 3A_684044820 and 3A_686681822. These markers could be useful for successful breeding of powdery mildew resistance in wheat.

Favorable Loci Identified for Stripe Rust Resistance in Chinese Winter Wheat Accessions via Genome-Wide Association Study.

Stripe rust (or yellow rust), caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating diseases of wheat worldwide. Currently, the utilization of resistant cultivars is the most viable way to reduce yield losses. In this study, a panel of 188 wheat accessions from China was evaluated for stripe rust resistance, and genome-wide association studies were performed using high-quality Diversity Arrays Technology markers. According to the phenotype and genotype data, a total of 26 significant marker-trait associations were identified, representing 18 quantitative trait loci (QTLs) on chromosomes 1B, 2A, 2B, 3A, 3B, 5A, 5B, 6B, 7B, and 7D. Of the 18 QTLs, almost all were associated with adult plant resistance (APR) except QYr.nwsuaf-6B.2, which was associated with all-stage resistance (also known as seedling resistance). Three of the 18 QTLs were mapped far from previously identified Pst resistance genes and QTLs and were considered potentially new loci. The other 15 QTLs were mapped close to known resistance genes and QTLs. Subsequent haplotype analysis for QYr.nwsuaf-2A and QYr.nwsuaf-7B.3 revealed the degrees of resistance of the panel in the APR stage. In summary, the favorable alleles identified in this study may be useful in breeding for disease resistance to stripe rust.

Anti-Aging Effect of Hemerocallis citrina Baroni Polysaccharide-Rich Extract on Caenorhabditis elegans.

Plant polysaccharides are important for anti-aging research. Polysaccharides from Hemerocallis citrina Baroni (H. citrina) have been reported to have antioxidant activity; however, their anti-aging roles and mechanisms are not clear. In this study, we extracted polysaccharides from H. citrina by an ultrasonic-assisted water extraction-alcohol precipitation method and chemically determined the physicochemical properties such as extraction yield, content, and in vitro antioxidant properties of H. citrina polysaccharide-rich extract (HCPRE). Using Caenorhabditis elegans (C. elegans) as a model animal, the anti-aging effect of HCPRE was investigated, and the mechanism of action of HCPRE was explored by the in vivo antioxidant level assay of C. elegans and the related gene expression assay. The extraction yield of HCPRE was 11.26%, the total polysaccharide content was 77.96%, and the main monosaccharide components were glucose and galactose. In addition, HCPRE exhibited good antioxidant activity both in vitro and in vivo. Under normal thermal stress and oxidative stress conditions, being fed 1200 µg/mL of HCPRE significantly prolonged the life span of C. elegans by 32.65%, 17.71%, and 32.59%, respectively. Our study showed that HCPRE exerted an anti-aging effect on C. elegans, and its mechanism involves increasing the activities of catalase (CAT) and superoxide dismutase (SOD), reducing the level of reactive oxygen species (ROS) and regulating the expression of related genes.

Classification of oolong tea varieties based on computer vision and convolutional neural networks.

BACKGROUND: In the contemporary food industry, accurate and rapid differentiation of oolong tea varieties holds paramount importance for traceability and quality control. However, achieving this remains a formidable challenge. This study addresses this lacuna by employing machine learning algorithms - namely support vector machines (SVMs) and convolutional neural networks (CNNs) - alongside computer vision techniques for the automated classification of oolong tea leaves based on visual attributes. RESULTS: An array of 13 distinct characteristics, encompassing color and texture, were identified from five unique oolong tea varieties. To fortify the robustness of the predictive models, data augmentation and image cropping methods were employed. A comparative analysis of SVM- and CNN-based models revealed that the ResNet50 model achieved a high Top-1 accuracy rate exceeding 93%. This robust performance substantiates the efficacy of the implemented methodology for rapid and precise oolong tea classification. CONCLUSION: The study elucidates that the integration of computer vision with machine learning algorithms constitutes a promising, non-invasive approach for the quick and accurate categorization of oolong tea varieties. The findings have significant ramifications for process monitoring, quality assurance, authenticity validation and adulteration detection within the tea industry. © 2023 Society of Chemical Industry.

[Interventional effect and inflammatory regulation mechanism of dihydroartemisinin combined with pregabalin on neuropathic pain mice].

This study aims to clarify the effects of dihydroartemisinin(DHA) combined with pregabalin(PGB) on neuropathic pain(NP) in mice and explore the neuroinflammatory regulatory mechanism. NP mice model was established using spinal nerve ligation, whereas the sham group exposed the spinal nerve without ligation. The mice were randomly divided into sham group, model group, PGB groups of low, medium, and high doses(PGB-L, PGB-M, and PGB-H, with 22, 45, and 91 mg·kg~(-1)), DHA group(16 mg·kg~(-1)), and DHA combined with PGB groups of low, medium, and high doses(DHA + PGB-L, DHA + PGB-M, and DHA + PGB-H). Administration by gavage 18 days after modeling. Von Frey and cold plate were used to detect mechanical pain threshold and cold pain sensitivity in mice. The tail suspension test and forced swimming test were used to investigate depressive behavior, and the open field test was used to estimate anxiety behavior. The Morris water maze was used to evaluate cognitive function. Liquid suspension chip technology was used to quantitatively analyze immune inflammation-related factors. Immunofluorescence was used to detect the expression of CC chemokine ligand 3(CCL3) and transmembrane protein 119(TMEM119). The results showed that compared with the sham group, the mechanical pain and cold pain sensitivity thresholds of the model group were significantly reduced, and the struggle time was significantly increased in the tail suspension test and forced swimming test. The activity time in the central area was significantly reduced in the open field test. The residence time in the second/fourth quadrant was significantly longer than that in other quadrants, and the latency time of platform climbing significantly increased after platform withdrawal in the Morris water maze experiment. The expression of CCL3 was significantly increased; the number of TMEM119 positive cells and the cell body area were significantly increased. Compared with the model group, the DHA + PGB-M group showed a significant increase in mechanical pain and cold pain sensitivity thresholds, as well as a significant increase in struggle time in the tail suspension test and forced swimming test. The activity time in the central area of the open field test was significantly reduced. The residence time in the second/fourth quadrant was significantly shorter than that in other quadrants, and the latency time of platform climbing after platform withdrawal was significantly reduced. Compared with the PGB-M group, the mechanical pain threshold of D14-17 in the DHA + PGB-M group was significantly increased, and the struggle time during forced swimming was significantly increased. The residence time in the second/fourth quadrant of the Morris water maze was significantly shorter than that in other quadrants. Compared with the model group, the expression of CCL3, the number of TMEM119 positive cells, and the cell body area in the DHA + PGB-M group were significantly decreased. This study indicates that DHA + PGB can enhance the analgesic effect of PGB on NP mice, break through the limitations of PGB tolerance, and make up for the shortcomings of PGB in antidepressant and cognitive improvement. Its mechanism may be related to regulating neuroinflammation by inhibiting the activation of microglial cells and expression of CCL3.

High-similarity analytical model of skylight polarization pattern based on position variations of neutral points.

The skylight polarization pattern contains rich information for navigation, meteorological monitoring, and remote sensing. In this paper, we propose a high-similarity analytical model by considering the influence of the solar altitude angle on the neutral point position variations for the distribution pattern of the polarized skylight. A novel function is built to determine the relationship between the neutral point position and solar elevation angle based on a large number of measured data. The experimental results show that the proposed analytical model achieves a higher similarity to measured data compared with existing models. Furthermore, data from several consecutive months verifies the universality, effectiveness, and accuracy of this model.

Improved emission performance of benzo[a]phenoxazine in aqueous solution through host-guest interaction.

To evaluate the contribution of host-guest chemistry in fluorescence enhancement under aqueous conditions, two benzo[a]phenoxazine derivatives with the adamantyl group were prepared. After they formed stable complexes with methyl-ß-cyclodextrin, their emissions at 625-825 nm were greatly increased and fluorescence quantum yields reached 11.5-12.6% in aqueous solution. Furthermore, they were successfully applied in fluorescence labeling of organelles in HeLa cells.

Application of microdialysis combined with UHPLC-QTOF/MS to screen for endogenous metabolites in aquatic organisms as biomarkers of exposure to an emerging contaminant, triclosan.

The detection of emerging contaminants (ECs) and understanding their ecotoxicity has brought new challenges to water pollution control. Triclosan (TCS), as an emerging contaminant, is a commonly used antibacterial agent widely present in the environment. Microdialysis (MD), as a sampling technique, can overcome some of the deficiencies of traditional approaches to sampling, using sources such as blood, urine, tissue, and target organs, in terms of invasiveness, time from collection to analysis, and possible changes during sample preparation. In this study, we coupled MD with analysis using UHPLC-QTOF/MS to identify the endogenous metabolites in the liver as biomarkers of the exposure of living crucian carp to TCS. The identified biomarkers were then quantified using UHPLC-MS/MS to continuously monitor the effect of TCS on endogenous metabolites in the liver of living crucian carp, which contributes to a better understanding of the toxicological effect of TCS. The experimental results demonstrated that TCS exposure interfered with the metabolic pathways of amino acids (L-isoleucine and L-histidine), purines (xanthine and hypoxanthine), and small nerve molecules (acetylcholine and choline).

Effect of placenta location detected by ultrasound on the severity of placenta accreta spectrum in patients with placenta previa and placenta accreta spectrum.

BACKGROUND: To evaluate the effect of placental location on the severity of placenta accreta spectrum (PAS). METHODS: We analyzed 390 patients with placenta previa combined with placenta accreta spectrum who underwent cesarean section between January 1, 2014 and December 30, 2020 in the electronic case database of the Second Hospital of Hebei Medical University. According to the position of the placenta, 390 placentas were divided into the posterior group (n = 89), the anterior group (n = 60) and the non-central group (n = 241). RESULTS: The history of cesarean delivery rates in the anterior group (91.67%) and the non-central group (85.71%) were statistically different from the posterior group (63.74%)(P < 0.001). Univariate logistic regression results showed that employment, urban living, gestational age, complete placenta previa, fetal presentation shoulder, gravidity, cesarean section and vaginal delivery were all predictors for the severity of placenta accreta (P < 0.05). The anterior group (P = 0.001, OR = 4.13, 95%CI: 1.84-9.24) and the non-central group (P = 0.001, OR = 2.90, 95%CI: 1.55-5.45) had a higher incidence of invasive accreta placentation than the posterior group, and were independent risk factors for invasive accreta placentation. CONCLUSION: Compared with posterior placenta, anterior and non-central placenta are independent risk factors for invasive PAS in patients with placenta previa, during which we should be more cautious in treatment.

Impact of Maternal Preoperative Hemoglobin Levels on Intraoperative Hemorrhage Risk in Placenta Accrete Spectrum Disorders: A Retrospective Cross-Sectional Study.

BACKGROUND Placenta accreta spectrum (PAS) disorders involve abnormal adhesion or invasion of chorionic villi through the myometrium and uterine serosa. Maternal anemia during pregnancy is common and may contribute to complications during delivery, particularly with abnormal placentation. This study examines the association between preoperative maternal hemoglobin levels and the risk of intraoperative massive hemorrhage in pregnant women with PAS disorders. MATERIAL AND METHODS A retrospective study included 538 consecutive participants (mean age=31.12±4.68 years) who underwent cesarean sections and met the diagnostic criteria for PAS disorders. Logistic regression analysis was performed to investigate the relationship between maternal preoperative hemoglobin levels and the risk of massive intraoperative hemorrhage (blood loss ≥1500 mL). RESULTS The incidence of intraoperative massive hemorrhage among patients with PAS disorders was 38.66%. The mean preoperative maternal hemoglobin level was 10.99±1.39 g/dL, and overall anemia incidence (<11 g/dL) was 48.88% in our study. After adjusting for potential confounders, a non-linear relationship was observed between preoperative maternal hemoglobin levels and the risk of intraoperative massive hemorrhage. When the preoperative hemoglobin level of pregnant women was below 11.5 g/dL (OR=0.52, 95% CI 0.39-0.70), the lower hemoglobin level significantly increased the risk of intraoperative hemorrhage. CONCLUSIONS Maternal preoperative hemoglobin levels were inversely associated with the risk of massive intraoperative hemorrhage in PAS disorders. A non-linear relationship was identified, with a turning point at 11.5 g/dL. These findings emphasize the importance of monitoring and managing maternal hemoglobin levels to mitigate the risk of intraoperative hemorrhage in pregnant women with PAS disorders.