Dynamic orbital hybridization triggered spin-disorder renormalization via super-exchange interaction for oxygen evolution reaction.

The oxygen evolution reaction (OER) underpins many aspects of energy storage and conversion in modern industry and technology, but which still be suffering from the dilemma of sluggish reaction kinetics and poor electrochemical performance. Different from the viewpoint of nanostructuring, this work focuses on an intriguing dynamic orbital hybridization approach to renormalize the disordering spin configuration in porous noble-metal-free metal-organic frameworks (MOFs) to accelerate the spin-dependent reaction kinetics in OER. Herein, we propose an extraordinary super-exchange interaction to reconfigure the domain direction of spin nets at porous MOFs through temporarily bonding with dynamic magnetic ions in electrolytes under alternating electromagnetic field stimulation, in which the spin renormalization from disordering low-spin state to high-spin state facilitates rapid water dissociation and optimal carrier migration, leading to a spin-dependent reaction pathway. Therefore, the spin-renormalized MOFs demonstrate a mass activity of 2,095.1 A gmetal-1 at an overpotential of 0.33 V, which is about 5.9 time of pristine ones. Our findings provide a insight into reconfiguring spin-related catalysts with ordering domain directions to accelerate the oxygen reaction kinetics.

DupScan: predicting and visualizing vertebrate genome duplication database.

Duplicated genes prevail in vertebrates and are important in the acquisition of new genes and novelties. Whole genome duplication (WGD) is one of the sources of duplicated genes. It can provide raw materials for natural selection by increasing the flexibility and complexity of the genome. WGDs are the driving force for the evolution of vertebrates and contribute greatly to their species diversity, especially in fish species with complicated WGD patterns. Here, we constructed the DupScan database (https://dupscan.sysumeg.com/) by integrating 106 chromosomal-level genomes, which can analyze and visualize synteny at both the gene and genome scales, visualize the Ka, Ks, and 4DTV values, and browse genomes. DupScan was used to perform functional adaptation for the intricate WGD investigation based on synteny matching. DupScan supports the analysis of five WGD rounds (R): VGD2 (vertebrate genome duplication 2), Ars3R (Acipenser-ruthenus-specific 3R), Pss3R (Polyodon-spathula-specific 3R), Ts3R (teleost-specific duplication 3R), Ss4R (salmonid-specific 4R), and Cs4R (carp-specific 4R). DupScan serves as one-stop analysis platform for synteny and WGD research in which users can analyze and predict synteny and WGD patterns across 106 species of whole genome sequences. This further aided us in elucidating genome evolutionary patterns across over 60,000 vertebrate species with synteny and WGD events.

Racial and Ethnic Underserved Populations Prescription Analgesic Use Before and After Lower Extremity Amputation in US Medicare.

BACKGROUND: Racial disparities exist in access to health care and management of multiple health conditions including chronic pain; however, racial disparities in pre- and postoperative pain management in lower extremity amputation are not well-studied. Our objective was to examine the association between different racial and ethnic groups and prescription opioid and other analgesics use before and after lower extremity amputation. We hypothesize prescription opioid and other analgesic use among Black, Hispanic, and Native American US Medicare beneficiaries undergoing lower extremity amputations will be lower compared to White US Medicare beneficiaries. METHODS: This retrospective cohort study included a 5% national sample of all Medicare beneficiaries from 2011 to 2015 and 15% national sample of fee-for-service Medicare beneficiaries from 2016 to 2018 undergoing nontraumatic, lower extremity amputations. The exposure of interest was racial and ethnic group membership (ie, Black, Hispanic, Native American, White, and others-with others being the combination of the categories Asian and other) as provided in Medicare claims data. Using multivariable generalized estimating equations with a logistic link to account for repeated measurements over time, we estimated the odds of prescription opioid use within 6 months before and after lower extremity amputation across different racial and ethnic groups separately, adjusting for sociodemographic and health status factors (eg, Elixhauser index). Adjusted odds ratios (aORs) and 95% confidence intervals (95% CI) were reported. RESULTS: Among 16,068 eligible beneficiaries who underwent major and minor amputations (mean age = 65.1 ± 12.7 years; female = 36.1%), 10,107 (62.9%) were White, 3462 (21.5%) were Black, 1959 (12.2%) were Hispanic, 247 (1.5%) were Native American, and 151 (2.9%) were beneficiaries of other races. During the 6 months before lower extremity amputation, Hispanic beneficiaries (aOR, 0.71, 95% CI, 0.65-0.78) and beneficiaries of other races (aOR, 0.60, 95% CI, 0.47-0.76) had significantly lower odds of using prescription opioids compared to White beneficiaries. Similarly, Hispanic beneficiaries (aOR, 0.78, 95% CI, 0.71-0.84) and beneficiaries of other races (aOR, 0.63, 95% CI, 0.51-0.78) were associated with lower odds of opioid use in the 6 months after amputation compared to White beneficiaries. CONCLUSIONS: Among fee-for-service Medicare beneficiaries, Hispanic and other (eg, Asian) fee-for-service Medicare beneficiaries had lower odds of prescription opioid use than their White counterparts before and after nontraumatic, lower extremity amputations. Efforts to determine the underlying reasons are needed to ensure equitable health care access.

Trajectories of Oral Anticoagulation Adherence and Associated Clinical Outcomes During Long-Term Anticoagulation Among Medicare Beneficiaries With Venous Thromboembolism.

BACKGROUND: Little is known about anticoagulation medication nonadherence patterns impacting effectiveness and safety outcomes in clinical practice. OBJECTIVE: We identified adherence trajectories of extended therapy with direct-acting oral anticoagulants (DOACs) and warfarin after 6 months initial anticoagulant therapy among Medicare beneficiaries with venous thromboembolism (VTE). We further assessed the associated recurrent VTE and major bleeding risks. METHODS: Using group-based trajectory models, this retrospective cohort study identified distinct beneficiary subgroups with similar adherence patterns of extended-phase anticoagulant treatment (DOACs or warfarin) for patients with VTE who completed 6 months of initial anticoagulant treatment. We examined associations between adherence trajectories and risks of recurrent VTE and major bleeding using inverse probability treatment weighted Cox proportional hazards models. RESULTS: Compared with no extended treatment, consistently high DOAC adherence was associated with decreased recurrent VTE risk (hazard ratio [HR] = 0.33, 95% confidence interval [CI] = 0.21-0.51) without increased major bleeding risk, and consistently high warfarin adherence was associated with decreased recurrent VTE risk (HR = 0.62, 95% CI = 0.40-0.95) and increased major bleeding risk (HR = 1.64, 95% CI = 1.12-2.41). Gradually declining adherence to DOACs (HR = 1.80, 95% CI = 1.07-3.03) or warfarin (HR = 2.34, 95% CI = 1.57-3.47) was associated with increased bleeding risk with no change in recurrent VTE risk. CONCLUSION AND RELEVANCE: This real-world evidence suggests persistently adhering to extended DOAC therapy is associated with lower recurrent VTE risk without increasing major bleeding among Medicare beneficiaries with VTE. Persistently adhering to extended warfarin therapy was associated with lower recurrent VTE risk but higher major bleeding risk.

How does 2D and 3D of urban morphology affect the seasonal land surface temperature in Island City? A block-scale perspective.

The global climate warming caused by urbanization has significantly affected the urban environment. Whilst land surface temperature (LST) is an important factor reflecting urban temperature, previous research on LST mostly focused on two-dimensional (2D) factors and rarely mentioned about the role of three-dimensional (3D) factors, particularly the LST variation characteristics of island cities. Therefore, this study examined the seasonal variation characteristics of urban LST by analyzing the impact of 2D and 3D urban morphology factors of different urban block types on LST in Xiamen Island. The main results are as follows. First, compact low layer (CL), a block type with a higher density of low-rise buildings, has a higher LST in any season. Under the same block density (BD), the higher the block average height (BH), the lower the LST. Second, among the 2D urban morphology factors, normalized difference vegetation index (NDVI) was the main factor for cities to reduce urban LST, especially in summer, while normalized difference built-up index (NDBI) was the opposite. Different from land cities, we found a positive correlation between modified normalized difference water body index (MNDWI) and LST in autumn and winter. Third, in the 3D urban morphology factors, sky view factor (SVF) was significantly positively correlated with LST, while building fluctuation (BF) was negatively correlated. The higher the SVF, the worse the radiation shielding effect between buildings. On the contrary, the higher the BF, the higher the building undulation, and the better the building radiation shielding. These findings should provide some quantitative insights for the future construction and planning of island cities, which can be used to improve the thermal environment of island cities and support the sustainable development of cities.

Light-driven Orderly Assembly of Ir-atomic Chains to Integrate a Dynamic Reaction Pathway for Acidic Oxygen Evolution.

This work suggests an intriguing light-driven atomic assembly proposal to orderly configure the distribution of reactive sites to optimize the spin-entropy-related orbital interaction and charge transfer from electrocatalysts to intermediates. Herein, the introduced fluorine (F) atoms acting as photo-corrosion centres in MnO1.9 F0.1 effectively soften the bonding interaction of Mn-O bonds in the IrCl3 solution. Therefore, partial Mn atoms can be successively replaced to form orderly atomic-hybridized catalysts with a spin-related low entropy due to the coexistence of Ir-atomic chains and clusters. The time-related elemental analysis demonstrates that the dynamic dissolution/redeposition of Ir clusters in acidic oxygen evolution leads to a reintegration of the reaction pathway to seek the switchable rate-limiting step with a lower activation energy.

Gene expression profiles provide insights into the survival strategies in deep-sea mussel (Bathymodiolus platifrons) of different developmental stages.

BACKGROUND: Deep-sea mussels living in the cold seeps with enormous biomass act as the primary consumers. They are well adapted to the extreme environment where light is absent, and hydrogen sulfide, methane, and other hydrocarbon-rich fluid seepage occur. Despite previous studies on diversity, role, evolution, and symbiosis, the changing adaptation patterns during different developmental stages of the deep-sea mussels remain largely unknown. RESULTS: The deep-sea mussels (Bathymodiolus platifrons) of two developmental stages were collected from the cold seep during the ocean voyage. The gills, mantles, and adductor muscles of these mussels were used for the Illumina sequencing. A total of 135 Gb data were obtained, and subsequently, 46,376 unigenes were generated using de-novo assembly strategy. According to the gene expression analysis, amounts of genes were most actively expressed in the gills, especially genes involved in environmental information processing. Genes encoding Toll-like receptors and sulfate transporters were up-regulated in gills, indicating that the gill acts as both intermedium and protective screen in the deep-sea mussel. Lysosomal enzymes and solute carrier responsible for nutrients absorption were up-regulated in the older mussel, while genes related to toxin resistance and autophagy were up-regulated in the younger one, suggesting that the older mussel might be in a vigorous stage while the younger mussel was still paying efforts in survival and adaptation. CONCLUSIONS: In general, our study suggested that the adaptation capacity might be formed gradually during the development of deep-sea mussels, in which the gill and the symbionts play essential roles.

Comparison of effectiveness and safety for low versus full dose of apixaban during extended phase oral anticoagulation in patients with venous thromboembolism.

BACKGROUND: The optimal dose of apixaban therapy to prevent asecondary venous thromboembolism (VTE) event remains unconfirmed. To investigate the effects of extended phase use of apixaban (2.5 vs. 5 mg twice daily) beyond 6 months of initial treatment on the risk of recurrent VTE and major bleeding events among patients with a history of VTE. METHODS: A retrospective cohort analysis of two large national insurance claims databases was conducted for patients diagnosed with VTE. Cox proportional hazard models after propensity score matching were used to compare the risk of recurrent VTE and major bleeding. RESULTS: There were no detected differences in recurrent VTE or major bleeding events between patients prescribed low versus full dose apixaban. CONCLUSION: This study provides evidence that apixaban 2.5 mg twice daily is an alternative option for extended phase therapy for risk reduction of VTE recurrence compared to apixaban 5 mg twice daily.

Loss of Heterozygosity for KrasG12D Promotes Malignant Phenotype of Pancreatic Ductal Adenocarcinoma by Activating HIF-2α-c-Myc-Regulated Glutamine Metabolism.

Loss of heterozygosity (LOH) for KRAS, in which a wild-type KRAS allele is progressively lost, promotes invasive and migratory abilities of pancreatic ductal adenocarcinoma (PDAC) cells and tissues. Moreover, the occurrence of KrasG12D-LOH activates nonclassical glutamine metabolism, which is related to the malignant behavior of PDAC cells. Herein, we aim to demonstrate the regulatory link between hypoxia-inducible factor-2α (HIF-2α) and glutamine metabolism that mediates malignant phenotypes in KrasG12D-LOH PDAC cells. HIF-2α-shRNA knockdown lentivirus transfection and metabolite analysis were performed in KrasG12D-LOH and KrasG12D cell lines, respectively. Cell proliferation, migration, and invasion were examined using Cell Counting Kit-8, colony formation, and Transwell assays. Cell cycle phase and apoptosis were determined using flow cytometry. Western blotting and real-time quantitative PCR were also performed. Additionally, a subcutaneous xenograft mouse model was established. LOH stimulated HIF-2α activity and transactivated c-Myc, which has a central regulatory effect on glutamine metabolism independent of hypoxia. Meanwhile, HIF-2α silencing repressed KrasG12D-LOH PDAC cell proliferation, invasion, and migration. HIF-2α knockdown inhibited glutamine uptake and GOT1 expression via a c-Myc-dependent pathway. Collectively, KrasG12D-LOH can activate HIF-2α to regulate c-Myc-mediated glutamine metabolism and promote malignant phenotypes. Moreover, targeting HIF-2α-c-Myc regulated nonclassical glutamine metabolism, providing a new therapeutic perspective for KrasG12D-LOH PDAC.

CircRHOT1 mediated cell proliferation, apoptosis and invasion of pancreatic cancer cells by sponging miR-125a-3p.

Pancreatic cancer patients are asymptomatic at early stages and leading to late diagnoses. Additionally, pancreatic cancer easily metastasizes and is resistant to radiotherapy and chemotherapy. Therefore, it is critical to understand the underlying molecular mechanisms involved in pancreatic cancer to develop more efficient diagnostic and treatment strategies. In this study, we demonstrated that circRHOT1 was overexpressed in pancreatic cancer tissues and cell lines, and it was found to directly bind to miR-125a-3p, acting as an endogenous sponge to inhibit its activity. Knockdown of circRHOT1 expression significantly inhibited proliferation as well as invasion, and it promoted apoptosis of pancreatic cancer cells via the regulation of E2F3 through the targeting of miR-125a-3p. Taken together, our results showed that circRHOT1 plays critical roles in regulating the biological functions of pancreatic cancer cells, suggesting that circRHOT1 may serve as a potential diagnostic marker and therapeutic target for patients with pancreatic cancer.

Loss of heterozygosity for KrasG12D promotes REDD1-dependent, non-canonical glutamine metabolism in pancreatic ductal adenocarcinoma.

Pancreatic cancer is associated with high mortality, and pancreatic ductal adenocarcinoma (PDAC) is its most common subtype. The rapid growth of PDAC is dependent on the non-canonical pathway of glutamine (Gln) utilization, and loss of heterozygosity for KrasG12D (KrasG12D-LOH) frequently observed in PDAC is associated with an aggressive and invasive phenotype. However, it remains unclear whether KrasG12D-LOH contributes to non-canonical Gln metabolism in PDAC. Here, we showed that KrasG12D-LOH leads to a substantial increase in non-canonical Gln metabolism in PDAC cells. Importantly, we observed elevated expression of regulated in DNA damage and development 1 (REDD1), which is activated in response to hypoxia and nutrient deprivation, in KrasG12D-LOH PDAC, and that REDD1 knockdown efficiently repressed KrasG12D-LOH-regulated Gln metabolism and suppressed proliferation, migration, and invasion of KrasG12D-LOH PDAC cells. These data provide evidence that REDD1 is a downstream target of KrasG12D-LOH and is involved in promoting non-canonical Gln metabolism in PDAC.

Magnetic and Electric Energy Harvesting Technologies in Power Grids: A Review.

With the development of intelligent modern power systems, real-time sensing and monitoring of system operating conditions have become one of the enabling technologies. Due to their flexibility, robustness and broad serviceable scope, wireless sensor networks have become a promising candidate for achieving the condition monitoring in a power grid. In order to solve the problematic power supplies of the sensors, energy harvesting (EH) technology has attracted increasing research interest. The motivation of this paper is to investigate the profiles of harnessing the electric and magnetic fields and facilitate the further application of energy scavenging techniques in the context of power systems. In this paper, the fundamentals, current status, challenges, and future prospects of the two most applicable EH methods in the grid-magnetic field energy harvesting (MEH) and electric field energy harvesting (EEH) are reviewed. The characteristics of the magnetic field and electric field under typical scenarios in power systems is analyzed first. Then the MEH and EEH are classified and reviewed respectively according to the structural difference of energy harvesters, which have been further evaluated based on the comparison of advantages and disadvantages for the future development trend.

Enhancement of scutellarin oral delivery efficacy by vitamin B12-modified amphiphilic chitosan derivatives to treat type II diabetes induced-retinopathy.

BACKGROUND: Diabetic retinopathy is the most common complication in diabetic patients relates to high expression of VEGF and microaneurysms. Scutellarin (Scu) turned out to be effective against diabetes related vascular endothelial cell dysfunction. However, its clinical applications have been limited by its low bioavailability. In this study, we formulated and characterized a novel intestinal target nanoparticle carrier based on amphiphilic chitosan derivatives (Chit-DC-VB12) loaded with scutellarin to enhance its bioavailability and then evaluated its therapeutic effect in experimental diabetic retinopathy model. RESULTS: Chit-DC-VB12 nanoparticles showed low toxicity toward the human colon adenocarcinoma (Caco-2) cells and zebra fish within concentration of 250 µg/ml, owing to good biocompatibility of chitosan. The scutellarin-loaded Chit-DC-VB12 nanoparticles (Chit-DC-VB12-Scu) were then prepared by self-assembly in aqueous solution. Scanning electron microscopy and dynamic light scattering analysis indicated that the Chit-DC-VB12-Scu nanoparticles were spherical particles in the sizes ranging from 150 to 250 nm. The Chit-DC-VB12-Scu nanoparticles exhibited high permeation in Caco-2 cell, indicated it could be beneficial to be absorbed in humans. We also found that Chit-DC-VB12 nanoparticles had a high cellular uptake. Bioavailability studies were performed in Sprague-Dawley rats, which present the area under the curve of scutellarin of Chit-DC-VB12-Scu was two to threefolds greater than that of free scutellarin alone. Further to assess the therapeutic efficacy of diabetic retinopathy, we showed Chit-DC-VB12-Scu down-regulated central retinal artery resistivity index and the expression of angiogenesis proteins (VEGF, VEGFR2, and vWF) of retinas in type II diabetic rats. CONCLUSIONS: Chit-DC-VB12 nanoparticles loaded with scutellarin have better bioavailability and cellular uptake efficiency than Scu, while Chit-DC-VB12-Scu nanoparticles alleviated the structural disorder of intraretinal neovessels in the retina induced by diabetes, and it also inhibited the retinal neovascularization via down-regulated the expression of angiogenesis proteins. In conclusion, the Chit-DC-VB12 nanoparticles enhanced scutellarin oral delivery efficacy and exhibited potential as small intestinal target promising nano-carriers for treatment of type II diabetes induced-retinopathy.

Fatty acid synthase (FASN) levels in serum of colorectal cancer patients: correlation with clinical outcomes.

Fatty acid synthase (FASN) is a common phenotype to many kinds of human cancers, such as those of the breast, ovary, pancreas, prostate, colon, and so on. Increased FASN levels have been detected in the serum of the patients with breast and pancreatic cancers. The relationship between the FASN level in serum and the clinicopathological characteristics of colorectal cancer is investigated in this study. FASN levels in serum were examined with enzyme-linked immunosorbent assay (ELISA) in 74 patients with colorectal cancer and 40 healthy persons. Pathological and clinical factors associated with FASN concentrations in serum were investigated and analyzed by statistical analysis. The FASN level in colorectal cancer patients' serum is significantly higher than that in healthy persons' serum. FASN levels in the serum of colorectal cancer patients are associated with tumor extent, lymph node metabasis status, distant metastasis, and tumor clinical stage. The 5-year overall survival rate and 5-year disease-free survival rate among patients with low FASN levels in serum are significantly higher than those among patients with high FASN levels in serum (log-rank P = 0.003). The high FASN level in serum is a promising independent predictor of colorectal cancers with advanced phases, late clinical stages, and shorter survival. These results suggest that FASN concentration in serum may be a potential and useful tumor marker.

Inhibition of PI3K/Akt/mTOR signaling pathway enhances the sensitivity of the SKOV3/DDP ovarian cancer cell line to cisplatin in vitro.

The activation of the PI3K/AKT/mTOR pathway plays a key role in ovarian cancer tumorigenesis, progression and chemotherapy resistance. This study aimed to explore the possible mechanism that PI-103, a dual inhibitor of phosphatidylinositide 3-kinase and mTOR, enhances the sensitivity of SKOV3/DDP ovarian cancer cell line to cisplatin chemotherapy. The results showed that PI-103 could significantly increase the sensitivity of SKVO3/DDP cells to cisplatin through inhibiting the activation of PI3K/Akt/mTOR signaling pathway and inducing cell cycle arrest and apoptosis.

Efficacy analysis of three brain stimulation techniques for Alzheimer's disease: a meta-analysis of repeated transcranial magnetic stimulation, transcranial direct current stimulation, and deep brain stimulation.

INTRODUCTION: This systematic review and meta-analysis study investigates the efficacy of repeated transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS), and deep brain stimulation (DBS) using neuropsychological assessments as a potential treatment option for Alzheimer's disease (AD). METHODS: PubMed, Embase, and the Cochrane Library were searched for studies on rTMS, tDCS, and DBS for the treatment of patients with AD between April 1970 and October 2022. The mini-Mental State Examination (MMSE) and AD Assessment Scale - Cognitive Subscale (ADAS-Cog) were adopted as the efficacy index. RESULTS: The analysis yielded 17 eligible studies. rTMS greatly improved the cognition of patients with AD (immediate post-treatment WMD of MMSE score: 2.06, p < 0.00001; short-term follow-up WMD of MMSE score: 2.12, p = 0.006; WMD of ADAS-Cog score in single-arm studies: -4.97, p = 0.001). DBS did not reverse the progression of cognitive decline (WMD of ADAS-Cog score in single-arm studies: 7.40, p < 0.00001). Furthermore, tDCS demonstrated no significant efficacy in improving cognition in random clinical trials or single-arm studies. CONCLUSION: rTMS is a promising non-medicinal alternative for cognitive improvement inpatients with AD.

Mitochondrial energy metabolism-related gene signature as a prognostic indicator for pancreatic adenocarcinoma.

Background: Pancreatic adenocarcinoma (PAAD) is a highly malignant gastrointestinal tumor and is associated with an unfavorable prognosis worldwide. Considering the effect of mitochondrial metabolism on the prognosis of pancreatic cancer has rarely been investigated, we aimed to establish prognostic gene markers associated with mitochondrial energy metabolism for the prediction of survival probability in patients with PAAD. Methods: Gene expression data were obtained from The Cancer Genome Atlas and Gene Expression Omnibus databases, and the mitochondrial energy metabolism-related genes were obtained from the GeneCards database. Based on mitochondrial energy metabolism score (MMs), differentially expressed MMRGs were established for MMs-high and MMs-low groups using ssGSEA. After the univariate Cox and least absolute and selection operator (LASSO) analyses, a prognostic MMRG signature was used in the multivariate Cox proportional regression model. Survival and immune cell infiltration analyses were performed. In addition, a nomogram based on the risk model was used to predict the survival probability of patients with PAAD. Finally, the expression of key genes was verified using quantitative polymerase chain reaction and immunohistochemical staining. Intro cell experiments were performed to evaluated the proliferation and invasion of pancreatic cancer cells. Results: A prognostic signature was constructed consisting of two mitochondrial energy metabolism-related genes (MMP11, COL10A1). Calibration and receiver operating characteristic (ROC) curves verified the good predictability performance of the risk model for the survival rate of patients with PAAD. Finally, immune-related analysis explained the differences in immune status between the two subgroups based on the risk model. The high-risk score group showed higher estimate, immune, and stromal scores, expression of eight checkpoint genes, and infiltration of M0 macrophages, which might indicate a beneficial response to immunotherapy. The qPCR results confirmed high expression of MMP11 in pancreatic cancer cell lines, and IHC also verified high expression of MMP11 in clinical pancreatic ductal adenocarcinoma tissues. In vitro cell experiments also demonstrated the role of MMP11 in cell proliferation and invasion. Conclusion: Our study provides a novel two-prognostic gene signature-based on MMRGs-that accurately predicted the survival of patients with PAAD and could be used for mitochondrial energy metabolism-related therapies in the future.

Synchronous monitoring of brain-heart electrophysiology using heart rate variability coupled with rapid quantitative electroencephalography in orthostatic hypotension patients with α-synucleinopathies: Rapid prediction of orthostatic hypotension and preliminary exploration of brain stimulation therapy.

BACKGROUND: In α-synucleinopathies, the dysfunction of the autonomic nervous system which typically manifests as orthostatic hypotension (OH) often leads to severe consequences and poses therapeutic challenges. This study aims to discover the brain-cardiac electrophysiological changes in OH patients with α-synucleinopathies using the rapid quantitative electroencephalography (qEEG) coupled with heart rate variability (HRV) technique to identify rapid, noninvasive biomarkers for early warning and diagnosis, as well as shed new light on complementary treatment approaches such as brain stimulation targets. METHODS: In this study, 26 subjects of α-synucleinopathies with OH (α-OH group), 21 subjects of α-synucleinopathies without OH (α-NOH group), and 34 healthy controls (control group) were included from September 2021 to August 2023 (NCT05527067). The heart rate-blood pressure variations in supine and standing positions were monitored, and synchronization parameters of seated resting-state HRV coupled with qEEG were collected. Time-domain and frequency-domain of HRV measures as well as peak frequency and power of the brainwaves were extracted. Differences between these three groups were compared, and correlations between brain-heart parameters were analyzed. RESULTS: The research results showed that the time-domain parameters such as MxDMn, pNN50, RMSSD, and SDSD of seated resting-state HRV exhibited a significant decrease only in the α-OH group compared to the healthy control group (p < 0.05), while there was no significant difference between the α-NOH group and the healthy control group. Several time-domain and frequency-domain parameters of seated resting-state HRV were found to be correlated with the blood pressure changes within the first 5 min of transitioning from supine to standing position (p < 0.05). Differences were observed in the power of beta1 waves (F4 and Fp2) and beta2 waves (Fp2 and F4) in the seated resting-state qEEG between the α-OH and α-NOH groups (p < 0.05). The peak frequency of theta waves in the Cz region also showed a difference (p < 0.05). The power of beta2 waves in the Fp2 and F4 brain regions correlated with frequency-domain parameters of HRV (p < 0.05). Additionally, abnormal electrical activity in the alpha, theta, and beta1 waves was associated with changes in heart rate and blood pressure within the first 5 min of transitioning from supine to standing position (p < 0.05). CONCLUSION: Rapid resting-state HRV with certain time-domain parameters below normal levels may serve as a predictive indicator for the occurrence of orthostatic hypotension (OH) in patients with α-synucleinopathies. Additionally, the deterioration of HRV parameters correlates with synchronous abnormal qEEG patterns, which can provide insights into the brain stimulation target areas for OH in α-synucleinopathy patients.

Hypotension with neurovascular changes and cognitive dysfunction: An epidemiological, pathobiological, and treatment review.

ABSTRACT: Hypotension is a leading cause of age-related cognitive impairment. The available literature evidences that vascular factors are associated with dementia and that hypotension alters cerebral perfusion flow and can aggravate the neurodegeneration of Alzheimer's disease (AD). Despite the discovery of biomarkers and the recent progress made in neurovascular biology, epidemiology, and brain imaging, some key issues remain largely unresolved: the potential mechanisms underlying the neural deterioration observed in AD, the effect of cerebrovascular alterations on cognitive deficits, and the positive effects of hypotension treatment on cognition. Therefore, further well-designed studies are needed to unravel the potential association between hypotension and cognitive dysfunction and reveal the potential benefits of hypotension treatment for AD patients. Here, we review the current epidemiological, pathobiological, and treatment-related literature on neurovascular changes and hypotension-related cognitive dysfunction and highlight the unsettled but imminent issues that warrant future research endeavors.

Brain white matter changes and their associations with non-motor dysfunction in orthostatic hypotension in α-synucleinopathy: A NODDI study.

BACKGROUND: The specific non-motor symptoms associated with α-synucleinopathies, including orthostatic hypotension (OH), cognitive impairment, and emotional abnormalities, have been a subject of ongoing controversy over the mechanisms underlying the development of a vicious cycle among them. The distinct structural alterations in white matter (WM) in patients with α-synucleinopathies experiencing OH, alongside their association with other non-motor symptoms, remain unexplored. This study employs axial diffusivity and density imaging (NODDI) to investigate WM damage specific to α-synucleinopathies with concurrent OH, delivering fresh evidence to supplement our understanding of the pathogenic mechanisms and pathological rationales behind the occurrence of a spectrum of non-motor functional impairments in α-synucleinopathies. METHODS: This study recruited 49 individuals diagnosed with α-synucleinopathies, stratified into an α-OH group (n = 24) and an α-NOH group (without OH, n = 25). Additionally, 17 healthy controls were included for supine and standing blood pressure data collection, as well as neuropsychological assessments. Magnetic resonance imaging (MRI) was utilized for the calculation of NODDI parameters, and tract-based spatial statistics (TBSS) were employed to explore differential clusters. The fibers covered by these clusters were defined as regions of interest (ROI) for the extraction of NODDI parameter values and the analysis of their correlation with neuropsychological scores. RESULTS: The TBSS analysis unveiled specific cerebral regions exhibiting disparities within the α-OH group as compared to both the α-NOH group and the healthy controls. These differences were evident in clusters that indicated a decrease in the acquisition of the neurite density index (NDI), a reduction in the orientation dispersion index (ODI), and an increase in the isotropic volume fraction (FISO) (p < 0.05). The extracted values from these ROIs demonstrated significant correlations with clinically assessed differences in supine and standing blood pressure, overall cognitive scores, and anxiety-depression ratings (p < 0.05). CONCLUSION: Patients with α-synucleinopathies experiencing OH exhibit distinctive patterns of microstructural damage in the WM as revealed by the NODDI model, and there is a correlation with the onset and progression of non-motor functional impairments.