Self-correction of cycle threshold values by a normal distribution-based process to improve accuracy of quantification in real-time digital PCR.

The digital polymerase chain reaction (dPCR) is a new and developing nucleic acid detection technology with high sensitivity that can realize the absolute quantitative analysis of samples. In order to improve the accuracy of quantitative results, real-time digital PCR emphasizes the kinetic information during amplification to identify prominent abnormal data. However, it is challenging to use a unified standard to accurately classify the amplification curve of each well as negative and positive, due to the interference caused by various factors in the experiment. In this work, a normal distribution-based cycle threshold value self-correcting model (NCSM) was established, which focused on the feature of the cycle threshold values in amplification curves and conducted continuous detection and correction on the whole. The cycle threshold value distribution was closer to the ideal normal distribution to avoid the influence of interference. Thus, the model achieves a more accurate classification between positive and negative results. The corrective process was applied to plasmid samples and resulted in an accuracy improvement from 92 to 99%. The coefficient of variation was below 5% when considering the quantitation of a range between 100 and 10,000 copies. At the same time, by utilizing this model, the distribution of cycle threshold values at the endpoint can be predicted with fewer thermal cycles, which can reduce the cycling time by around 25% while maintaining a consistency of more than 98%. Therefore, using the NCSM can effectively enhance the quantitative accuracy and increase the detection efficiency based on the real-time dPCR platform.

Automatic Seizure Detection Based on Stockwell Transform and Transformer.

Epilepsy is a chronic neurological disease associated with abnormal neuronal activity in the brain. Seizure detection algorithms are essential in reducing the workload of medical staff reviewing electroencephalogram (EEG) records. In this work, we propose a novel automatic epileptic EEG detection method based on Stockwell transform and Transformer. First, the S-transform is applied to the original EEG segments, acquiring accurate time-frequency representations. Subsequently, the obtained time-frequency matrices are grouped into different EEG rhythm blocks and compressed as vectors in these EEG sub-bands. After that, these feature vectors are fed into the Transformer network for feature selection and classification. Moreover, a series of post-processing methods were introduced to enhance the efficiency of the system. When evaluating the public CHB-MIT database, the proposed algorithm achieved an accuracy of 96.15%, a sensitivity of 96.11%, a specificity of 96.38%, a precision of 96.33%, and an area under the curve (AUC) of 0.98 in segment-based experiments, along with a sensitivity of 96.57%, a false detection rate of 0.38/h, and a delay of 20.62 s in event-based experiments. These outstanding results demonstrate the feasibility of implementing this seizure detection method in future clinical applications.

A bioinformatic analysis study of m7G regulator-mediated methylation modification patterns and tumor microenvironment infiltration in glioblastoma.

BACKGROUND: Glioblastoma is one of the most common brain cancers in adults, and is characterized by recurrence and little curative effect. An effective treatment for glioblastoma patients remains elusive worldwide. 7-methylguanosine (m7G) is a common RNA modification, and its role in tumors has become a research hotspot. METHODS: By searching for differentially expressed genes related to m7G, we generated a prognostic signature via cluster analysis and established classification criteria of high and low risk scores. The effectiveness of classification was validated using the Non-negative matrix factorization (NMF) algorithm, and repeatedly verified using training and test groups. The dimension reduction method was used to clearly show the difference and clinical significance of the data. All analyses were performed via R (version 4.1.2). RESULTS: According to the signature that included four genes (TMOD2, CACNG2, PLOD3, and TMSB10), glioblastoma patients were divided into high and low risk score groups. The survival rates between the two groups were significantly different, and the predictive abilities for 1-, 3-, and 5-year survivals were effective. We further established a Nomogram model to further examine the signature,as well as other clinical factors, with remaining significant results. Our signature can act as an independent prognostic factor related to immune-related processes in glioblastoma. CONCLUSIONS: Our research addresses the gap in knowledge in the m7G and glioblastoma research fields. The establishment of a prognostic signature and the extended analysis of the tumor microenvironment, immune correlation, and tumor mutation burden further suggest the important role of m7G in the development and development of this disease. This work will provide support for future research.

The possible pathogenesis of macular caldera in patients with North Carolina macular dystrophy.

BACKGROUND: This study provides a detailed description of a Chinese family with North Carolina macular dystrophy (NCMD) and explores its possible pathogenesis. METHODS: Five individuals from a three-generation family underwent general ophthalmic examination, multi-imaging examinations and visual electrophysiology examinations when possible. Genetic characterization was carried out by target region sequencing and high-throughput sequencing in affected patients. RESULTS: Despite severe fundus changes, patients had relatively good visual acuity. Genetic analysis showed that affected patients had PRDM13 gene duplication and heterozygous mutations of the ABCA4 gene. Optical coherence tomography (OCT) showed an abnormal retinal pigment epithelium (RPE) layer in patients with grade 2 lesions, while the neurosensory retina was relatively normal. In grade 3 patients, RPE and choroid atrophy were greater than that of the neurosensory retina, showing concentric atrophy. CONCLUSIONS: RPE and choroidal atrophy were found to play an important role in the development of macular caldera.

The response of anti-VEGF therapy and tamoxifen withdrawal of tamoxifen-induced cystoid macular edema in the same patient.

BACKGROUND: Numerous cases with ocular toxicity secondary to tamoxifen have been reported, and became more apparent with keratopathy, cataract, optic neuritis, macular holes, crystalline retinopathy with or without cystoid macular edema (CME). Withdrawing tamoxifen with the approval of the oncologist is the major treatment for cases with tamoxifen-induced retinopathy. CASE PRESENTATION: We herein reported a patient with a two-year history of painless and reduced visual acuity in both eyes who received tamoxifen therapy for 6 years. Tamoxifen-induced rentinopathy with CME showed significant development even though the patient has already discontinued tamoxifen treatment for 6 months. Anatomic improvements after intravitreal ranibizumab injection in both eyes were significant but were temporary. Surprisingly, CME in both eyes has been resolved spontaneously after 10 months in the penultimate visit without any therapy. CONCLUSION: Intravitreal ranibizumab injection temporarily improved the anatomy of the eyes in a case with tamoxifen-induced CME, and only tamoxifen withdrawal can bring a sustained effect.

Heterogeneous modification of through-hole microwell chips for ultralow cross-contamination digital polymerase chain reaction.

Chip-based dPCR (cdPCR) with a physical boundary between micro-units allows for high parallelism, robustness and sensitivity. However, cross-contamination between micro-units is still a problem that affects the accuracy of results. To overcome this problem, we introduced a heterogeneous modification strategy by microcontact printing to prepare a through-hole microwell chip (TMC) with a hydrophobic exterior surface and hydrophilic interior surface. The modified TMC can reduce cross-contamination (sample residual rate (SRR) of (4.9 ± 1.5)%) by an efficient partitioning yield (unit filling rate (UFR) of (91.1 ± 2.2)%). The sample-residual properties of modified TMCs could be tuned by the reaction conditions. As the contact time increased, the surface CA of the TMC increased, which caused decreases of the SRR and UFR. However, prolonging the contact time to 25 s would cause a sharp reduction of the UFR. The modified TMCs with high UFRs were used for further dPCR studies. The fluorescence images of dPCR chips were collected by fluorescence microscopy and a self-developed optical system, followed by image processing and data statistics to obtain quantitative results. The copy number variation results of the surface hydrophobic TMC was closer to the true value compared to that of the hydrophilic TMC. The results indicated that the sample residue on the hydrophilic TMC would increase the number of positive points, which would cause false positives and clustering error. The absolute quantitative results of gradient dilution plasmid DNA of JAK2 gene using modified TMC also proved that heterogeneous modification made the quantitative results more accurate. The heterogeneous modified TMC is expected to be used for high-throughput, high-sensitivity and high-specificity biological analyses, such as circulating tumor DNA and cell analysis.

Blood Coagulation Testing Smartphone Platform Using Quartz Crystal Microbalance Dissipation Method.

Blood coagulation function monitoring is important for people who are receiving anticoagulation treatment and a portable device is needed by these patients for blood coagulation self-testing. In this paper, a novel smartphone based blood coagulation test platform was proposed. It was developed based on parylene-C coated quartz crystal microbalance (QCM) dissipation measuring and analysis. The parylene-C coating constructed a robust and adhesive surface for fibrin capturing. The dissipation factor was obtained by measuring the frequency response of the sensor. All measured data were sent to a smartphone via Bluetooth for dissipation calculation and blood coagulation results computation. Two major coagulation indexes, activated partial thromboplastin time (APTT) and prothrombin time (PT) were measured on this platform compared with results by a commercial hemostasis system in a clinical laboratory. The measurement results showed that the adjusted R-square (R²) value for APTT and PT measurements were 0.985 and 0.961 respectively. The QCM dissipation method for blood coagulation measurement was reliable and effective and the platform together with the QCM dissipation method was a promising solution for point of care blood coagulation testing.

Acclimatization to middle altitude hypoxia protects against developmental and cognitive deficits caused by acute fetal hypoxia in mice.

Acute fetal hypoxia (AFH) can elicit postnatal motor deficits and cognitive impairments. To test whether lifelong acclimatization to middle altitude (MA) hypoxia has protective effects on the impairments caused by AFH, ICR mice bred at 1 900 m altitude for 6-7 generations were evaluated under AFH. On gestation day 9 (GD 9), 13 (GD 13) or 17 (GD 17), pregnant mice received a single exposure to acute hypoxia (7% O2, 6 h). Physiological and neurodevelopmental behaviors, motor function (open field), spatial learning and memory (Morris water maze), and anxiety level (elevated plus maze) were examined in the offspring from neonate to adulthood. In the neonatal age, among all the physiological and behavioral landmarks, almost no differences were found in the hypoxia groups. In the juvenile period, no obvious impairments of motor function and anxiety level were found in the hypoxia groups. In the adult period, no obvious impairment of motor function was found in hypoxia groups; Interestingly, AFH groups' offspring showed normal or enhanced long-term spatial memory ability after AFH. These data suggest that AFH cause little abnormalities in the offspring of MA-adapted mice. To further investigate the underlying mechanisms, the neuronal numbers in behavior-related brain areas (accumbens nucleus, basal amygdala and hippocampus) were counted, and the physiological parameters of the blood were measured. The morphological data showed that no obvious neuronal necrosis was found in all hypoxia groups. In addition, blood tests showed that red blood corpuscle count, hemoglobin concentration and hematocrit levels in mice raised at MA were markedly higher in both males and females, compared with controls raised at the sea level. These data suggest that lifelong acclimatization to MA hypoxia has protective effects against development delay, motor deficits and spatial learning and memory impairments induced by AFH, and the protective effects may be due to higher hemoglobin concentration and hematocrit levels in the blood. The findings may provide a better understanding of fetal hypoxia and potential intervention treatments.

Morphine-induced conditioned place preference in rhesus monkeys: Resistance to inactivation of insula and extinction.

Drug addicts experience strong craving episodes in response to drug-associated cues. Attenuating these responses using pharmacological or behavioral approaches could aid recovery from addiction. Cue-induced drug seeking can be modeled using the conditioned place preference procedure (CPP). Our previous work showed that conditioned place preference (CPP) can be induced by administration of increasing doses of morphine in rhesus monkeys. Here, we investigated whether expression of morphine-induced CPP can be attenuated by inhibiting activity of insular cortex or by repeated unreinforced exposures to the CPP test. The insula has been demonstrated to be involved in addiction to several drugs of abuse. To test its role in morphine CPP, bilateral cannulae were implanted into the insula in seven adult monkeys. The CPP was established using a biased apparatus by intramuscular injections of morphine at increasing doses (1.5, 3.0 and 4.5mg/kg) for each monkey. After the monkeys established morphine CPP, their insulae were reversibly inactivated by bilateral microinjection with 5% lidocaine (40µl) prior to the post-conditioning test (expression) of CPP using a within-subject design. The microinjections of lidocaine failed to affect CPP expression when compared to saline injections. We subsequently investigated morphine-associated memory during six episodes of CPP tests performed in these monkeys over the following 75.0±0.2months. While the preference score showed a declining trend with repeated testing, morphine-induced CPP was maintained even on the last test performed at 75months post-conditioning. This observation indicated strong resistance of morphine-induced memories to extinction in rhesus monkeys. Although these data do not confirm involvement of insula in morphine-induced CPP, our observation that drug-associated memories can be maintained over six drug-free years following initial experience with morphine has important implications for treatment of drug addiction using extinction therapy.

Nitrosothiol formation and protection against Fenton chemistry by nitric oxide-induced dinitrosyliron complex formation from anoxia-initiated cellular chelatable iron increase.

Dinitrosyliron complexes (DNIC) have been found in a variety of pathological settings associated with (•)NO. However, the iron source of cellular DNIC is unknown. Previous studies on this question using prolonged (•)NO exposure could be misleading due to the movement of intracellular iron among different sources. We here report that brief (•)NO exposure results in only barely detectable DNIC, but levels increase dramatically after 1-2 h of anoxia. This increase is similar quantitatively and temporally with increases in the chelatable iron, and brief (•)NO treatment prevents detection of this anoxia-induced increased chelatable iron by deferoxamine. DNIC formation is so rapid that it is limited by the availability of (•)NO and chelatable iron. We utilize this ability to selectively manipulate cellular chelatable iron levels and provide evidence for two cellular functions of endogenous DNIC formation, protection against anoxia-induced reactive oxygen chemistry from the Fenton reaction and formation by transnitrosation of protein nitrosothiols (RSNO). The levels of RSNO under these high chelatable iron levels are comparable with DNIC levels and suggest that under these conditions, both DNIC and RSNO are the most abundant cellular adducts of (•)NO.

Large-scale horizontally aligned ZnO microrod arrays with controlled orientation, periodic distribution as building blocks for chip-in piezo-phototronic LEDs.

A novel method of fabricating large-scale horizontally aligned ZnO microrod arrays with controlled orientation and periodic distribution via combing technology is introduced. Horizontally aligned ZnO microrod arrays with uniform orientation and periodic distribution can be realized based on the conventional bottom-up method prepared vertically aligned ZnO microrod matrix via the combing method. When the combing parameters are changed, the orientation of horizontally aligned ZnO microrod arrays can be adjusted (θ = 90° or 45°) in a plane and a misalignment angle of the microrods (0.3° to 2.3°) with low-growth density can be obtained. To explore the potential applications based on the vertically and horizontally aligned ZnO microrods on p-GaN layer, piezo-phototronic devices such as heterojunction LEDs are built. Electroluminescence (EL) emission patterns can be adjusted for the vertically and horizontally aligned ZnO microrods/p-GaN heterojunction LEDs by applying forward bias. Moreover, the emission color from UV-blue to yellow-green can be tuned by investigating the piezoelectric properties of the materials. The EL emission mechanisms of the LEDs are discussed in terms of band diagrams of the heterojunctions and carrier recombination processes.

Targeting MS4A4A: A novel pathway to improve immunotherapy responses in glioblastoma.

INTRODUCTION: Glioblastoma (GBM) remains a challenging brain tumor to treat, with limited response to PD-1 immunotherapy due to tumor-associated macrophages (TAMs), specifically the M2 phenotype. This study explores the potential of MS4A4A (membrane spanning four domains, subfamily A, member 4A) inhibition in driving M2 macrophage polarization toward the M1 phenotype via the ferroptosis pathway to enhance the effectiveness of immunotherapy in GBM. METHODS: Single-cell RNA sequencing and spatial transcriptomic analyses were employed to characterize M2 macrophages and MS4A4A expression in GBM. In vitro studies utilizing TAM cultures, flow cytometry, and western blot validations were conducted to assess the impact of MS4A4A on the tumor immune microenvironment and M2 macrophage polarization. In vivo models, including subcutaneous and orthotopic transplantation in mice, were utilized to evaluate the effects of MS4A4A knockout and combined immune checkpoint blockade (ICB) therapy on tumor growth and response to PD-1 immunotherapy. RESULTS: Distinct subsets of GBM-associated macrophages were identified, with spatial distribution in tumor tissue elucidated. In vivo experiments demonstrated that inhibiting MS4A4A and combining ICB therapy effectively inhibited tumor growth, reshaped the tumor immune microenvironment by reducing M2 TAM infiltration and enhancing CD8+ T-cell infiltration, ultimately leading to complete tumor eradication. CONCLUSION: MS4A4A inhibition shows promise in converting M2 macrophages to M1 phenotype via ferroptosis, decreasing M2-TAM infiltration, and enhancing GBM response to PD-1 immunotherapy. These findings offer a novel approach to developing more effective immunotherapeutic strategies for GBM.

Single Effective Complex Loading into Zero-Mode Waveguides Optimized with Fluorescence Evaluation at Quenching and Accumulation Checkpoints.

Single-molecule detection with high accuracy and specialty plays an important role in biomedical diagnosis and screening. Zero-mode waveguides (ZMWs) enable the possibility of single biological molecule detection in real time. Nevertheless, the absence of a reliable assessment for single effective complex loading has constrained further applications of ZMWs in complex interaction. Both the quantity and activity of the complex loaded into ZMWs have a critical effect on the efficiency of detection. Herein, a fluorescence evaluation at quenching and accumulation checkpoints was established to assess and optimize single effective complex loading into ZMWs. A primer-template-enzyme ternary complex was designed, and then an evaluation for quantity statistics at the quenching checkpoint and functional activity at the accumulation checkpoint was used to validate the effectiveness of complexes loaded into ZMWs. By optimizing the parameters such as loading time, procedures, and enzyme amount, the single-molecule effective occupancy was increased to 25.48%, achieving 68.86% of the theoretical maximum value (37%) according to Poisson statistics. It is of great significance to provide effective complex-loading validation for improving the sample-loading efficiency of single-molecule assays or sequencing in the future.

How Oxidative Stress Induces Depression?

Depression increasingly affects a wide range and a large number of people worldwide, both physically and psychologically, which makes it a social problem requiring prompt attention and management. Accumulating clinical and animal studies have provided us with substantial insights of disease pathogenesis, especially central monoamine deficiency, which considerably promotes antidepressant research and clinical treatment. The first-line antidepressants mainly target the monoamine system, whose drawbacks mainly include slow action and treatment resistant. The novel antidepressant esketamine, targeting on central glutamatergic system, rapidly and robustly alleviates depression (including treatment-resistant depression), whose efficiency is shadowed by potential addictive and psychotomimetic side effects. Thus, exploring novel depression pathogenesis is necessary, for seeking more safe and effective therapeutic methods. Emerging evidence has revealed vital involvement of oxidative stress (OS) in depression, which inspires us to pursue antioxidant pathway for depression prevention and treatment. Fully uncovering the underlying mechanisms of OS-induced depression is the first step towards the avenue, thus we summarize and expound possible downstream pathways of OS, including mitochondrial impairment and related ATP deficiency, neuroinflammation, central glutamate excitotoxicity, brain-derived neurotrophic factor/tyrosine receptor kinase B dysfunction and serotonin deficiency, the microbiota-gut-brain axis disturbance and hypothalamic-pituitary-adrenocortical axis dysregulation. We also elaborate on the intricate interactions between the multiple aspects, and molecular mechanisms mediating the interplay. Through reviewing the related research progress in the field, we hope to depict an integral overview of how OS induces depression, in order to provide fresh ideas and novel targets for the final goal of efficient treatment of the disease.

Revealing the Binding Events of Single Proteins on Exosomes Using Nanocavity Antennas beyond Zero-Mode Waveguides.

Exosomes (EXOs) play a crucial role in biological action mechanisms. Understanding the biological process of single-molecule interactions on the surface of the EXO membrane is essential for elucidating the precise function of the EXO receptor. However, due to dimensional incompatibility, monitoring the binding events between EXOs of tens to hundreds of nanometers and biomolecules of nanometers using existing nanostructure antennas is difficult. Unlike the typical zero-mode waveguides (ZMWs), this work presents a nanocavity antenna (λvNAs) formed by nanocavities with diameters close to the visible light wavelength dimensions. Effective excitation volumes suitable for observing single-molecule fluorescence were generated in nanocavities of larger diameters than typical ZMWs; the optimal signal-to-noise ratio obtained was 19.5 when the diameter was 300 nm and the incident angle was ∼50°. EXOs with a size of 50-150 nm were loaded into λvNAs with an optimized diameter of 300-500 nm, resulting in appreciable occupancy rates that overcame the nanocavity size limitation for large-volume biomaterial loading. Additionally, this method identified the binding events between the single transmembrane CD9 proteins on the EXO surface and their monoclonal antibody anti-CD9, demonstrating that λvNAs expanded the application range beyond subwavelength ZMWs. Furthermore, the λvNAs provide a platform for obtaining in-depth knowledge of the interactions of single molecules with biomaterials ranging in size from tens to hundreds of nanometers.

Integrating machine learning and bioinformatics analysis to m6A regulator-mediated methylation modification models for predicting glioblastoma patients' prognosis and immunotherapy response.

BACKGROUND: Epigenetic regulations of immune responses are essential for cancer development and growth. As a critical step, comprehensive and rigorous explorations of m6A methylation are important to determine its prognostic significance, tumor microenvironment (TME) infiltration characteristics and underlying relationship with glioblastoma (GBM). METHODS: To evaluate m6A modification patterns in GBM, we conducted unsupervised clustering to determine the expression levels of GBM-related m6A regulatory factors and performed differential analysis to obtain m6A-related genes. Consistent clustering was used to generate m6A regulators cluster A and B. Machine learning algorithms were implemented for identifying TME features and predicting the response of GBM patients receiving immunotherapy. RESULTS: It is found that the m6A regulatory factor significantly regulates the mutation of GBM and TME. Based on Europe, America, and China data, we established m6Ascore through the m6A model. The model accurately predicted the results of 1206 GBM patients from the discovery cohort. Additionally, a high m6A score was associated with poor prognoses. Significant TME features were found among the different m6A score groups, which demonstrated positive correlations with biological functions (i.e., EMT2) and immune checkpoints. CONCLUSIONS: m6A modification was important to characterize the tumorigenesis and TME infiltration in GBM. The m6Ascore provided GBM patients with valuable and accurate prognosis and prediction of clinical response to various treatment modalities, which could be useful to guide patient treatments.

Efficient Simultaneous Detection of Metabolites Based on Electroenzymatic Assembly Strategy.

Objective and Impact Statement: We describe an electroenzymatic mediator (EM) sensor based on an electroenzymatic assembly peak separation strategy, which can efficiently realize the simultaneous detection of 3 typical cardiovascular disease (CVD) metabolites in 5 µl of plasma under one test. This work has substantial implications toward improving the efficiency of chronic CVD assessment. Introduction: Monitoring CVD of metabolites is strongly associated with disease risk. Independent and time-consuming detection in hospitals is unfavorable for chronic CVD management. Methods: The EM was flexibly designed by the cross-linking of electron mediators and enzymes, and 3 EM layers with different characteristics were assembled on one electrode. Electrons were transferred under tunable potential; 3 metabolites were quantitatively detected by 3 peak currents that correlated with metabolite concentrations. Results: In this study, the EM sensor showed high sensitivity for the simultaneous detection of 3 metabolites with a lower limit of 0.01 mM. The linear correlation between the sensor and clinical was greater than 0.980 for 242 patients, and the consistency of risk assessment was 94.6%. Conclusion: Metabolites could be expanded by the EM, and the sensor could be a promising candidate as a home healthcare tool for CVD risk assessment.

Effect of morphine on conditioned place preference in rhesus monkeys.

In rodents, a conditioned place preference (CPP) can be induced by morphine. In the current study, we designed a biased place conditioning paradigm to test the rewarding effects of morphine in freely moving rhesus monkeys. Five monkeys were first placed in three serial rooms with the doors open between them for three days. After this habituation period, during which baseline preference for each of the two end rooms was measured, CPP conditioning occurred when the monkeys were injected intramuscularly with morphine at an increasing dose (1.5, 3, 4.5 mg/kg) before they entered the non-preferred room and on alternate days, with saline before they entered the preferred room. Morphine and saline treatment lasted for six days, respectively. CPP was tested 24 hours after the end of CPP training. The result showed that in all five monkeys, CPP was induced by the morphine treatment. The preference lasted for at least 15.3 ± 1.7 months.

The heparinase-linked differential time method allows detection of heparin potency in whole blood with high sensitivity and dynamic range.

Anticoagulation therapy with heparin is an effective treatment against thrombosis. Heparin tends to cause spontaneous bleeding and requires regular monitoring during therapy. Most high-sensitivity heparin sensors have focused on the concentration detection in clarified buffer solution. However, the pharmacodynamics of heparin vary depending on individual patient or disease, while potency detection with high sensitivity and dynamic range outperforms concentration detection in clinical diagnosis. In this study, a novel heparinase-linked differential time (HLDT) method was established with a two-zone of Graphene modified Carbon (GR-C) sensor, which was utilized to evaluate heparin potency in whole blood. It was based on electrochemical measurement of clotting time shifting associated with presence or absence of heparinase. Heparinase inhibits the anticoagulant ability of heparin by forming a heparin-antithrombin-thrombin complex during coagulation. And the intensity and peak time of electrochemical current were associated with thrombin activity and clotting on the electrode. The results demonstrated that the sensor had high selectivity for heparin potency in 10 µL of whole blood with a detection limit of 0.1 U/mL, and the linear detection range was 0.1-5 U/mL. The coefficient of variation (CV) of the peak time was less than 5%, and linear correlation between the GR-C sensor and the TEG-5000 instrument was 0.987. Thus, the HLDT method has better clinical application due to its good repeatability, high sensitivity and wide range in heparin potency evaluation.

Multi-omics profiles refine L-dopa decarboxylase (DDC) as a reliable biomarker for prognosis and immune microenvironment of clear cell renal cell carcinoma.

Background: Increasing evidence indicates that L-dopa decarboxylase (DDC), which mediates aberrant amino acid metabolism, is significantly associated with tumor progression. However, the impacts of DDC are not elucidated clearly in clear cell renal cell carcinoma (ccRCC). This study aimed to evaluate DDC prognostic value and potential mechanisms for ccRCC patients. Methods: Transcriptomic and proteomic expressions of and clinical data including 532 patients with ccRCC (The Cancer Genome Atlas RNA-seq data), 226 ccRCC samples (Gene Expression Omnibus), 101 ccRCC patients from the E-MTAB-1980 cohort, and 232 patients with ccRCC with proteogenomic data (Fudan University Shanghai Cancer Center) were downloaded and analyzed to investigate the prognostic implications of DDC expression. Cox regression analyses were implemented to explore the effect of DDC expression on the prognosis of pan-cancer. The "limma" package identified the differentially expressed genes (DEGs) between high DDC subgroups and low DDC groups. Functional enrichments were performed based DEGs between DDC subgroups. The differences of immune cell infiltrations and immune checkpoint genes between DDC subgroups were analyzed to identify potential influence on immune microenvironment. Results: We found significantly decreased DDC expression in ccRCC tissues compared with normal tissues from multiple independent cohorts based on multi-omics data. We also found that DDC expression was correlated with tumor grades and stages.The following findings revealed that lower DDC expression levels significantly correlated with shorter overall survival (P <0.001) of patients with ccRCC. Moreover, we found that DDC expression significantly correlated with an immunosuppressive tumor microenvironment, higher intra-tumoral heterogeneity, elevated expression of immune checkpoint CD274, and possibly mediated malignant behaviors of ccRCC cells via the PI3k/Akt signaling pathway. Conclusion: The present study is the first to our knowledge to indicate that decreased DDC expression is significantly associated with poor survival and an immune-suppressive tumor microenvironment in ccRCC. These findings suggest that DDC could serve as a biomarker for guiding molecular diagnosis and facilitating the development of novel individual therapeutic strategies for patients with advanced ccRCC.