Publications by authors named "Tao Liu"

3,429 Publications

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Improving SERS Sensitivity toward Trace Sulfonamides: The Key Role of Trade-Off Interfacial Interactions among the Target Molecules, Anions, and Cations on the SERS Active Surface.

Anal Chem 2021 Jun 11. Epub 2021 Jun 11.

State Key Laboratory of Marine Environmental Science, Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, Center for Marine Environmental Chemistry & Toxicology, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.

In recent years, ensuring the rational use and effective control of antibiotics has been a major focus in the eco-environment, which requires an effective monitoring method. However, on-site rapid detection of antibiotics in water environments remains a challenging issue. In this study, surface-enhanced Raman spectroscopy (SERS) was used to systematically achieve selective, rapid, and highly sensitive detection of sulfonamides, based on their fingerprint characteristics. The results show that the trade-off between the competitive and coadsorption behaviors of target molecules and agglomerates (inorganic salts) on the surface of the SERS substrate determines whether the molecules can be detected with high sensitivity. Based on this, the qualitative differentiation and quantitative detection of three structurally similar antibiotics, sulfadiazine, sulfamerazine, and sulfamethazine, were achieved, with the lowest detectable concentration being 1 μg/L for sulfadiazine and 50 μg/L for sulfamerazine and sulfamethazine.
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http://dx.doi.org/10.1021/acs.analchem.1c01530DOI Listing
June 2021

Conduction Band Energy-Level Engineering for Improving Open-Circuit Voltage in Antimony Selenide Nanorod Array Solar Cells.

Adv Sci (Weinh) 2021 Jun 10:e2100868. Epub 2021 Jun 10.

National-Local Joint Engineering Laboratory of New Energy Photoelectric Devices, College of Physics Science and Technology, Hebei University, Baoding, 071002, China.

Antimony selenide (Sb Se ) nanorod arrays along the [001] orientation are known to transfer photogenerated carriers rapidly due to the strongly anisotropic one-dimensional crystal structure. With advanced light-trapping structures, the Sb Se nanorod array-based solar cells have excellent broad spectral response properties, and higher short-circuit current density than the conventional planar structured thin film solar cells. However, the interface engineering for the Sb Se nanorod array-based solar cell is more crucial to increase the performance, because it is challenging to coat a compact buffer layer with perfect coverage to form a uniform heterojunction interface due to its large surface area and length-diameter ratio. In this work, an intermeshing In S nanosheet-CdS composite as the buffer layer, compactly coating on the Sb Se nanorod surface is constructed. The application of In S -CdS composite buffers build a gradient conduction band energy configuration in the Sb Se /buffer heterojunction interface, which reduces the interface recombination and enhances the transfer and collection of photogenerated electrons. The energy-level regulation minimizes the open-circuit voltage deficit at the interfaces of buffer/Sb Se and buffer/ZnO layers in the Sb Se solar cells. Consequently, the Sb Se nanorod array solar cell based on In S -CdS composite buffers achieves an efficiency of as high as 9.19% with a V of 461 mV.
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http://dx.doi.org/10.1002/advs.202100868DOI Listing
June 2021

The impacts of precipitation patterns on dengue epidemics in Guangzhou city.

Int J Biometeorol 2021 Jun 11. Epub 2021 Jun 11.

Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China.

Some studies have demonstrated that precipitation is an important risk factor of dengue epidemics. However, current studies mostly focused on a single precipitation variable, and few studies focused on the impact of precipitation patterns on dengue epidemics. This study aims to explore optimal precipitation patterns for dengue epidemics. Weekly dengue case counts and meteorological data from 2006 to 2018 in Guangzhou of China were collected. A generalized additive model with Poisson distribution was used to investigate the association between precipitation patterns and dengue. Precipitation patterns were defined as the combinations of three weekly precipitation variables: accumulative precipitation (Pre_A), the number of days with light or moderate precipitation (Pre_LMD), and the coefficient of precipitation variation (Pre_CV). We explored to identify optimal precipitation patterns for dengue epidemics. With a lead time of 10 weeks, minimum temperature, relative humidity, Pre_A, and Pre_LMD were positively associated with dengue, while Pre_CV was negatively associated with dengue. A precipitation pattern with Pre_A of 20.67-55.50 mm per week, Pre_LMD of 3-4 days per week, and Pre_CV less than 1.41 per week might be an optimal precipitation pattern for dengue epidemics in Guangzhou. The finding may be used for climate-smart early warning and decision-making of dengue prevention and control.
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http://dx.doi.org/10.1007/s00484-021-02149-2DOI Listing
June 2021

SiRNA in MSC-derived exosomes silences CTGF gene for locomotor recovery in spinal cord injury rats.

Stem Cell Res Ther 2021 Jun 10;12(1):334. Epub 2021 Jun 10.

Department of Orthopaedics, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Dalian, 116001, Liaoning Province, China.

Background: How to obtain a small interfering RNA (siRNA) vector has become a moot point in recent years. Exosomes (Exo) show advantages of long survival time in vivo, high transmission efficiency, and easy penetration across the blood-spinal cord barrier, renowned as excellent carriers of bioactive substances.

Methods: We applied mesenchymal stem cell (MSC)-derived exosomes as the delivery of synthesized siRNA, which were extracted from rat bone marrow. We constructed exosomes-siRNA (Exo-siRNA) that could specifically silence CTGF gene in the injury sites by electroporation. During the administration, we injected Exo-siRNA into the tail vein of SCI rats, RESULTS: In vivo and in vitro experiments showed that Exo-siRNA not only effectively inhibited the expressions of CTGF gene, but quenched inflammation, and thwarted neuronal apoptosis and reactive astrocytes and glial scar formation. Besides, it significantly upregulated several neurotrophic factors and anti-inflammatory factors, acting as a facilitator of locomotor recovery of rats with spinal cord injury (SCI).

Conclusions: In conclusion, this study has combined the thoroughness of gene therapy and the excellent drug-loading characteristics of Exo for the precise treatment of SCI, which will shed new light on the drug-loading field of Exo.
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http://dx.doi.org/10.1186/s13287-021-02401-xDOI Listing
June 2021

Methylome profiling identifies TCHH methylation in CfDNA as a noninvasive marker of liver metastasis in colorectal cancer.

FASEB J 2021 Jul;35(7):e21720

Division of General Surgery, Peking University First Hospital, Beijing, China.

Methylation of circulating free DNA (CfDNA) has emerged as an efficient marker of tumor screening and prognostics. However, no efficient methylation marker has been developed for monitoring liver metastasis (LM) in colorectal cancer (CRC). Utilizing methylome profiling and bisulfite sequencing polymerase chain reaction of paired primary and LM sites, significantly increased methylation of TCHH was identified in the process of LM in CRC in the present study. Methylight analysis of TCHH methylation in CfDNA displayed a promisingly discriminative power between CRC with and without LM. Besides, significant coefficient of TCHH methylation and LM tumor volume was also validated. Together, these results indicated the potential of TCHH methylation in CfDNA as a monitoring marker of LM in CRC.
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http://dx.doi.org/10.1096/fj.202100266RDOI Listing
July 2021

Unconventional Quantum Sound-Matter Interactions in Spin-Optomechanical-Crystal Hybrid Systems.

Phys Rev Lett 2021 May;126(20):203601

Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama 351-0198, Japan.

We predict a set of unusual quantum acoustic phenomena resulting from sound-matter interactions in a fully tunable solid-state platform in which an array of solid-state spins in diamond are coupled to quantized acoustic waves in a one-dimensional optomechanical crystal. We find that, by using a spatially varying laser drive that introduces a position-dependent phase in the optomechanical interaction, the mechanical band structure can be tuned in situ, consequently leading to unconventional quantum sound-matter interactions. We show that quasichiral sound-matter interactions can occur, with tunable ranges from bidirectional to quasiunidirectional, when the spins are resonant with the bands. When the solid-state spin frequency lies within the acoustic band gap, we demonstrate the emergence of an exotic polariton bound state that can mediate long-range tunable, odd-neighbor, and complex spin-spin interactions. This work expands the present exploration of quantum phononics and can have wide applications in quantum simulations and quantum information processing.
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http://dx.doi.org/10.1103/PhysRevLett.126.203601DOI Listing
May 2021

Tetramethylpyrazine Improves Cognitive Function of Alzheimer's Disease Mice by Regulating SSTR4 Ubiquitination.

Drug Des Devel Ther 2021 1;15:2385-2399. Epub 2021 Jun 1.

Department of Neurology, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, 570311, Hainan, People's Republic of China.

Purpose: Many researches have investigated the functions of tetramethylpyrazine (TMP) in Alzheimer's disease (AD). This study aimed to discuss the underlying mechanism of TMP in AD mice.

Methods: TMP (200 mg/kg) was administered to 6-month-old APP/PS1 transgenic mice, and behavioral changes and hippocampal nerve injury in AD mice were detected. Apoptosis and autophagy-related protein levels were detected. Changes in gene expression before and after TMP treatment were compared using transcriptome sequencing. The effects of Cullin 4B (CUL4B) overexpression and somatostatin receptor 4 (SSTR4) silencing on AD symptoms and SSTR4 ubiquitination in APP/PS1 mice were observed. SH-SY5Y and PC12 cells were treated with 25 μmol/L Aβ and TMP to observe cell viability, apoptosis, and autophagy. Cell viability and apoptosis were measured again after treatment with proteasome inhibitor MG132 or lysosomal inhibitor 3-mA.

Results: TMP treatment improved the behavioral cognition of APP/PS1 mice and improved the neuronal apoptosis and damage in brain tissue. CUL4B was significantly upregulated in APP/PS1 mouse brain tissue, and SSRT4 protein was downregulated, and the levels of CUL4B and SSRT4 were negatively correlated. TMP treatment downregulated CUL4B, inhibited SSRT4 ubiquitination and upregulated SSRT4 protein level in APP/PS1 mouse brain tissue, while CUL4B overexpression or SSRT4 silencing reversed the effect of TMP. TMP and MG132 improved the decreased activity, increased apoptosis and increased SSRT4 protein in SH-SY5Y and PC12 cells treated with Aβ, but not 3-mA. CUL4B overexpression promoted the ubiquitination of SSTR4 in cells, which partially reversed the effect of TMP.

Conclusion: TMP could improve the cognitive ability of AD mice by inhibiting CUL4B expression and the ubiquitination degradation of SSTR, and alleviating neuronal apoptosis and injury. This study may offer a new therapeutic option for AD treatment.
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http://dx.doi.org/10.2147/DDDT.S290030DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8179737PMC
June 2021

Synthesis of novel diosgenyl saponin analogs and evaluation effects of rhamnose moeity on their cytotoxic activity.

Carbohydr Res 2021 May 31;506:108359. Epub 2021 May 31.

Department of Pharmacy, Qilu Hospital of Shandong University, Jinan, 250012, Shandong Province, PR China. Electronic address:

Diosgenyl saponins, as a type of natural products derived from plants, are the main active component of traditional chinese medicine. Inspiringly, a large number of natural diosgensyl saponins have been shown to exert excellent toxicity to hepatocellular cancer (HCC) cells. In order to better understand the relationship between the structures and their biological effects, a group of diosgenyl saponins (1-4 as natural products and 5 and 6 as their analogs) were efficiently synthesized. The cytotoxic activity of these compounds was evaluated on human hepatocellular carcinoma (HepG2) cells. Structure-activity relationship studies showed that the pentasaccharide or hexasaccharide saponin analogs were relatively less active than their corresponding disaccharide analogue or dioscin. The extension of 4-branched rhamnose moiety on these saponin does not exhibit significant effect on their cytotoxic activity, which disclosed that a certain number and the linkage mode of rhamnose moieties could influence the cytotoxicity of steroid saponins on HepG2 cells.
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http://dx.doi.org/10.1016/j.carres.2021.108359DOI Listing
May 2021

The association of cooking fuels with cataract among adults aged 50 years and older in low- and middle-income countries: Results from the WHO Study on global AGEing and adult health (SAGE).

Sci Total Environ 2021 May 29;790:148093. Epub 2021 May 29.

Shanghai Medical College, Fudan University, Shanghai, China. Electronic address:

Reducing household air pollution and protecting eye health are essential to achieve the Sustainable Development Goals (SDGs). There is contradictory evidence about the association between cooking fuels and cataract among adults aged 50 years and older. WHO Study on global AGEing and adult health (SAGE) was conducted in six low- and middle-income countries (LMICs). We used propensity-score method (inverse probability of weighting) and logistic regression to examine the association between cooking fuels and self-reported cataract. Odds ratio (OR) estimates and 95% confidence intervals (CIs) were calculated. Overall, use of unclean fuels was associated with an adjusted OR of cataract of 1.42 (95%CIs, 1.29-1.56). In subgroup analysis, unclean cooking fuels increased 1.71 (95%CI, 1.46-2.01) and 1.53 (95%CI, 1.30-1.79) times the risk of cataract in India and China, respectively, whereas no association was found in other countries. In gender-stratified analyses, unclean fuel use was associated with a 1.27 (95%CI, 1.13-1.44) times risk for males and 1.67 (95%CI, 1.44-1.94) times risk for females. Higher cataract risk attributed to unclean fuels was observed among those aged over 60 (1.45; 95%CI, 1.28-1.64) than people aged under 60 (1.39; 95%CI, 1.20-1.62). OR was higher in rural area (1.74; 95%CI, 1.51-2.00) than urban area (1.24; 95%CI, 1.09-1.41). Our results indicate that unclean fuels may be associated with self-reported cataract, but it varied among different LMICs. Higher risk was found in females, people older than 60 years old and those who live in rural areas. The result of this study provides useful information to support transition to clean household energy and eye health promotion in LMICs. Greater efforts should be taken to protect vulnerable populations.
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http://dx.doi.org/10.1016/j.scitotenv.2021.148093DOI Listing
May 2021

Time-Driven Adaptive Control of Switched Systems With Application to Electro-Hydraulic Unit.

IEEE Trans Cybern 2021 Jun 7;PP. Epub 2021 Jun 7.

This article focuses on the H∞ adaptive tracking problem of uncertain switched systems. A key point of the study is to set up a multiple piecewise Lyapunov function framework which provides an effective tool for designing an adaptive switching controller consisting of a state-feedback and time-driven switching signal and a time-driven adaptive law. The proposed switching signal guarantees the solvability of the H∞ adaptive tracking problem for uncertain switched systems. Significantly, it provides plenty of adjusting time for the adaptive tracking control strategy to damp the transient caused by switching and avoids frequent switching. A novel time-driven adaptive switching controller is established such that the tracking error asymptotically converges to zero and all the signals in the error dynamic system are bounded under an achieved disturbance attenuation level. The solvability criterion ensuring an H∞ adaptive tracking performance is established for the uncertain switched systems, where the solvability of the H∞ adaptive tracking problem for individual subsystems is not required. Finally, the proposed method is applied to the electro-hydraulic unit.
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http://dx.doi.org/10.1109/TCYB.2021.3077599DOI Listing
June 2021

Synthesis, Magnetic Properties, and Electronic Structure of Magnetic Topological Insulator MnBiSe.

Nano Lett 2021 Jun 7. Epub 2021 Jun 7.

Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States.

The intrinsic magnetic topological insulators MnBiTe and MnBiSe support novel topological states related to symmetry breaking by magnetic order. Unlike MnBiTe, the study of MnBiSe has been inhibited by the lack of bulk crystals, as the van der Waals (vdW) crystal is not the thermodynamic equilibrium phase. Here, we report the layer-by-layer synthesis of vdW MnBiSe crystals using nonequilibrium molecular beam epitaxy. Atomic-resolution scanning transmission electron microscopy and scanning tunneling microscopy identify a well-ordered vdW crystal with septuple-layer base units. The magnetic properties agree with the predicted layered antiferromagnetic ordering but disagree with its predicted out-of-plane orientation. Instead, our samples exhibit an easy-plane anisotropy, which is explained by including dipole-dipole interactions. Angle-resolved photoemission spectroscopy reveals the gapless Dirac-like surface state, which demonstrates that MnBiSe is a topological insulator above the magnetic-ordering temperature. These studies show that MnBiSe is a promising candidate for exploring rich topological phases of layered antiferromagnetic topological insulators.
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http://dx.doi.org/10.1021/acs.nanolett.1c00141DOI Listing
June 2021

Plasma Circulating Tumor DNA Sequencing Predicts Minimal Residual Disease in Resectable Esophageal Squamous Cell Carcinoma.

Front Oncol 2021 20;11:616209. Epub 2021 May 20.

Department of Thoracic Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China.

Esophageal squamous cell carcinoma (ESCC) is lethal as tumors are rarely detected at an early stage and have a high recurrence rate. There are no particularly useful biomarkers for the prognostic prediction of ESCC. Circulating tumor DNA (ctDNA) is becoming an important biomarker for non-invasive diagnosis and monitoring tumor prognosis. Here, we aimed to analyze variations in plasma cell-free DNA (cfDNA) amount to search for minimal residual disease (MRD). Plasma and white blood cells (WBCs) of 60 patients were collected before tumor resection and a week after surgery. Tumor specimens were also collected as formalin-fixed paraffin-embedded (FFPE) samples. All samples were extracted to analyze the genetic alterations of 61 genes using capture-based next-generation sequencing (NGS). Tumor variants were detected in 38 patients with ESCC, and the two driver genes with the highest mutation frequency were and . Of the pre-surgical plasma cfDNA samples, 73.7% of identified variants matched the tissue. In patients who did not receive adjuvant therapy after surgery, postoperative cfDNA-positive patients had shorter overall survival (hazard ratios (HR), 25.8; 95% CI, 2.7-242.6; P = 0.004) and were more likely to relapse than postoperative cfDNA-negative patients (HR, 184.6; 95% CI, 3.6-9576.9; P = 0.01). Detection of ctDNA after surgical tumor excision is associated with tumor relapse and disease-specific survival, and can be used as a prognostic biomarker for MRD detection in ESCC.
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http://dx.doi.org/10.3389/fonc.2021.616209DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8173109PMC
May 2021

Merging C(sp)-H activation with DNA-encoding.

Chem Sci 2020 Sep 7;11(45):12282-12288. Epub 2020 Sep 7.

Department of Chemistry, The Scripps Research Institute 10550 North Torrey Pines Road, La Jolla CA 92037 USA

DNA-encoded library (DEL) technology has the potential to dramatically expedite hit identification in drug discovery owing to its ability to perform protein affinity selection with millions or billions of molecules in a few experiments. To expand the molecular diversity of DEL, it is critical to develop different types of DNA-encoded transformations that produce billions of molecules with distinct molecular scaffolds. Sequential functionalization of multiple C-H bonds provides a unique avenue for creating diversity and complexity from simple starting materials. However, the use of water as solvent, the presence of DNA, and the extremely low concentration of DNA-encoded coupling partners (0.001 M) have hampered the development of DNA-encoded C(sp)-H activation reactions. Herein, we report the realization of palladium-catalyzed C(sp)-H arylation of aliphatic carboxylic acids, amides and ketones with DNA-encoded aryl iodides in water. Notably, the present method enables the use of alternative sets of monofunctional building blocks, providing a linchpin to facilitate further setup for DELs. Furthermore, the C-H arylation chemistry enabled the on-DNA synthesis of structurally-diverse scaffolds containing enriched C(sp) character, chiral centers, cyclopropane, cyclobutane, and heterocycles.
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http://dx.doi.org/10.1039/d0sc03935gDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8162953PMC
September 2020

Monofloral Triadica Cochinchinensis Honey Polyphenols Improve Alcohol-Induced Liver Disease by Regulating the Gut Microbiota of Mice.

Front Immunol 2021 21;12:673903. Epub 2021 May 21.

School of Life Sciences, Nanchang University, Nanchang, China.

Honey produced from medicinal plants holds great promise for human health. Increasing evidence suggests that the gut microbiota plays an important role in liver pathology after alcohol intake. The aim of this study was to identify the polyphenol composition of honey (TCH), and to study the potential effect of honey polyphenols on the regulation of gut microbes in mice with alcohol-induced liver injury and the improvement of alcohol-induced liver disease. For these purposes, a total of 190 compounds were identified and 27 of them were quantified by ultraperformance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UPLC-Q/TOF-MS) and we successfully established a mouse model of alcohol-induced liver injury. The results show that TCH polyphenols can significantly restore the levels of ALT and AST, and TCH intervention can significantly improve the pathological changes of liver tissue in alcohol-exposed mice. Additionally, a significant decrease was observed in Firmicutes/Bacteroidetes after TCH treatment. Moreover, KEGG pathways of ATP-binding cassette (ABC) transporters, two-component system and biosynthesis of amino acids enriched the most differentially expressed genes after TCH intervention for 8 weeks. Our results may have important implications for the use of TCH as a functional food component with potential therapeutic utility against alcohol-induced liver disease.
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http://dx.doi.org/10.3389/fimmu.2021.673903DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8175904PMC
May 2021

Glucocappasalin Induces G2/M-Phase Arrest, Apoptosis, and Autophagy Pathways by Targeting CDK1 and PLK1 in Cervical Carcinoma Cells.

Front Pharmacol 2021 20;12:671138. Epub 2021 May 20.

Clinical Genetics Laboratory, Clinical Medical College, Affiliated Hospital and College of Basic Medicine and School of Pharmacy and School of Food and Biological Engineering, Chengdu University, Chengdu, China.

Glucocappasalin (GCP), a natural product derived from the seeds of (L.) Webb. ex Prantl, exhibits potential antitumor activity in HeLa cervical carcinoma cells. In this study, we investigated the anti-cervical cancer property of GCP through the induction of cell cycle arrest, apoptosis, and autophagy and , and elucidated the underlying molecular mechanisms. We demonstrated that treatment with GCP inhibited the growth of HeLa, Siha, and Ca Ski cell lines in a dose-dependent manner, with HeLa cells displaying particular sensitivity to the GCP treatment. Subsequently, the expression of cyclin-dependent kinase 1 (CDK1) and polo like kinase 1 (PLK1) were evaluated in HeLa cells using the CDK1 kinase assay kit, the fluorescence polarization assay, real-time quantitative PCR, and western blotting. Our results demonstrate that GCP could be employed to attenuate the expression of CDK1 and PLK1 in a dose- and time-dependent manner. The complementary results obtained by flow cytometry and western blotting allowed us to postulate that GCP may exhibit its antitumor effects by inducing G2/M cell cycle arrest. Moreover, HeLa cells treated with GCP exhibited a loss in mitochondrial membrane potential, together with the activation of caspases 3 and 9, and poly ADP-ribose polymerase (PARP). Additionally, we found that GCP could increase the formation of acidic vesicular organelles (AVOs), as well as the levels of Beclin1, LC3-II, p62, and Atg5 proteins in HeLa cells. Further studies indicated that GCP triggered autophagy the suppression of the PI3K/AKT/mTOR signaling pathways. The autophagy inhibitor 3-methyladenine (3-MA) was used to determine whether autophagy affects the apoptosis induced by GCP. Interestingly, the inhibition of autophagy attenuated apoptosis. anti-tumor experiments indicated that GCP (60 mg/kg, i.p.) markedly reduced the growth of HeLa xenografts in nude mice without apparent toxicity. Taken together, we demonstrate that GCP induces cell cycle G2/M-phase arrest, apoptosis, and autophagy by acting on the PI3K/AKT/mTOR signaling pathways in cervical carcinoma cells. Thus, GCP may represent a promising agent in the eradication of cervical cancer.
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http://dx.doi.org/10.3389/fphar.2021.671138DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8172611PMC
May 2021

Effects of plant species diversity on nematode community composition and diversity in a long-term biodiversity experiment.

Oecologia 2021 Jun 6. Epub 2021 Jun 6.

German Centre of Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstraße 4, 04103, Leipzig, Germany.

Diversity loss has been shown to change the soil community; however, little is known about long-term consequences and underlying mechanisms. Here, we investigated how nematode communities are affected by plant species richness and whether this is driven by resource quantity or quality in 15-year-old plant communities of a long-term grassland biodiversity experiment. We extracted nematodes from 93 experimental plots differing in plant species richness, and measured above- and belowground plant biomass production and soil organic carbon concentrations (C) as proxies for resource quantity, as well as C/N ratio and specific root length (SRL) as proxies for resource quality. We found that nematode community composition and diversity significantly differed among plant species richness levels. This was mostly due to positive plant diversity effects on the abundance and genus richness of bacterial-feeding, omnivorous, and predatory nematodes, which benefited from higher shoot mass and soil C in species-rich plant communities, suggesting control via resource quantity. In contrast, plant-feeding nematodes were negatively influenced by shoot mass, probably due to higher top-down control by predators, and were positively related to SRL and C/N, indicating control via resource quality. The decrease of the grazing pressure ratio (plant feeders per root mass) with plant species richness indicated a higher accumulation of plant-feeding nematodes in species-poor plant communities. Our results, therefore, support the hypothesis that soil-borne pathogens accumulate in low-diversity communities over time, while soil mutualists (bacterial-feeding, omnivorous, predatory nematodes) increase in abundance and richness in high-diversity plant communities, which may contribute to the widely-observed positive plant diversity-productivity relationship.
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http://dx.doi.org/10.1007/s00442-021-04956-1DOI Listing
June 2021

Reduction of air pollutants and associated mortality during and after the COVID-19 lockdown in China: Impacts and implications.

Environ Res 2021 Jun 2;200:111457. Epub 2021 Jun 2.

Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China; Department of Public Health, School of Medicine, Jinan University, Guangzhou, China. Electronic address:

Although strict lockdown measurements implemented during the COVID-19 pandemic have dramatically reduced the anthropogenic-based emissions, changes in air quality and its health impacts remain unclear in China. We comprehensively described air pollution during and after the lockdown periods in 2020 compared with 2018-2019, and estimated the mortality burden indicated by the number of deaths and years of life lost (YLL) related to the air pollution changes. The mean air quality index (AQI), PM, PM, NO, SO and CO concentrations during the lockdown across China declined by 18.2 (21.2%), 27.0 μg/m (28.9%), 10.5 μg/m (18.3%), 8.4 μg/m (44.2%), 13.1 μg/m (38.8%), and 0.3 mg/m (27.3%) respectively, when compared to the same periods during 2018-2019. We observed an increase in O concentration during the lockdown by 5.5 μg/m (10.4%), and a slight decrease after the lockdown by 3.4 μg/m (4.4%). As a result, there were 51.3 (95%CI: 32.2, 70.1) thousand fewer premature deaths (16.2 thousand during and 35.1 thousand after the lockdown), and 1066.8 (95%CI: 668.7, 1456.8) thousand fewer YLLs (343.3 thousand during and 723.5 thousand after the lockdown) than these in 2018-2019. Our findings suggest that the COVID-19 lockdown has caused substantial decreases in air pollutants except for O, and that substantial human health benefits can be achieved when strict control measures for air pollution are taken to reduce emissions from vehicles and industries. Stricter tailored policy solutions of air pollution are urgently needed in China and other countries, especially in well-developed industrial regions, such as upgrading industry structure and promoting green transportation.
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http://dx.doi.org/10.1016/j.envres.2021.111457DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8170876PMC
June 2021

Infectious disease mRNA vaccines and a review on epitope prediction for vaccine design.

Brief Funct Genomics 2021 Jun 4. Epub 2021 Jun 4.

Data Science Institute, Faculty of Engineering & IT, University of Technology Sydney, 15 Broadway, Ultimo, 2007, New South Wales, Australia.

Messenger RNA (mRNA) vaccines have recently emerged as a new type of vaccine technology, showing strong potential to combat the COVID-19 pandemic. In addition to SARS-CoV-2 which caused the pandemic, mRNA vaccines have been developed and tested to prevent infectious diseases caused by other viruses such as Zika virus, the dengue virus, the respiratory syncytial virus, influenza H7N9 and Flavivirus. Interestingly, mRNA vaccines may also be useful for preventing non-infectious diseases such as diabetes and cancer. This review summarises the current progresses of mRNA vaccines designed for a range of diseases including COVID-19. As epitope study is a primary component in the in silico design of mRNA vaccines, we also survey on advanced bioinformatics and machine learning algorithms which have been used for epitope prediction, and review on user-friendly software tools available for this purpose. Finally, we discuss some of the unanswered concerns about mRNA vaccines, such as unknown long-term side effects, and present with our perspectives on future developments in this exciting area.
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http://dx.doi.org/10.1093/bfgp/elab027DOI Listing
June 2021

Development of peptide epoxyketones as selective immunoproteasome inhibitors.

Eur J Med Chem 2021 May 25;221:113556. Epub 2021 May 25.

ZJU-ENS Joint Laboratory of Medicinal Chemistry, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, PR China. Electronic address:

A series of epoxyketone analogues with varying N-caps and P3-configurations were designed, synthesized and evaluated. We found that D-Ala in P3 was crucial for β5i selectivity over β5c. Notably, compounds 20j (β5i IC = 26.0 nM, 25-fold selectivity) and 20l (β5i IC = 25.1 nM, 24-fold selectivity) with the D-configuration at P3 were the most selective inhibitors. Although 20j and 20l showed only moderate anti-proliferative activity against RPMI-8226 and MM.1S cell lines, based on our experiments, it indicates that the inhibition of β5i alone is not sufficient to exert anticancer effects and may rely on the complementary inhibition of β1i, β5c and β5i. These data further increase our understanding of immunoproteasome inhibitors in hematologic malignancies.
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http://dx.doi.org/10.1016/j.ejmech.2021.113556DOI Listing
May 2021

Brain Age Estimation From MRI Using Cascade Networks with Ranking Loss.

IEEE Trans Med Imaging 2021 Jun 4;PP. Epub 2021 Jun 4.

Chronological age of healthy people is able to be predicted accurately using deep neural networks from neuroimaging data, and the predicted brain age could serve as a biomarker for detecting aging-related diseases. In this paper, a novel 3D convolutional network, called two-stage-age-network (TSAN), is proposed to estimate brain age from T1-weighted MRI data. Compared with existing methods, TSAN has the following improvements. First, TSAN uses a two-stage cascade network architecture, where the first-stage network estimates a rough brain age, then the second-stage network estimates the brain age more accurately from the discretized brain age by the first-stage network. Second, to our knowledge, TSAN is the first work to apply novel ranking losses in brain age estimation, together with the traditional mean square error (MSE) loss. Third, densely connected paths are used to combine feature maps with different scales. The experiments with 6586 MRIs showed that TSAN could provide accurate brain age estimation, yielding mean absolute error (MAE) of 2.428 and Pearson's correlation coefficient (PCC) of 0.985, between the estimated and chronological ages. Furthermore, using the brain age gap between brain age and chronological age as a biomarker, Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI) can be distinguished from healthy control (HC) subjects by support vector machine (SVM). Classification AUC in AD/HC and MCI/HC was 0.904 and 0.823, respectively. It showed that brain age gap is an effective biomarker associated with risk of dementia, and has potential for early-stage dementia risk screening. The codes and trained models have been released on GitHub.
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http://dx.doi.org/10.1109/TMI.2021.3085948DOI Listing
June 2021

Neuroprotection of -benzyl Eicosapentaenamide in Neonatal Mice Following Hypoxic-Ischemic Brain Injury.

Molecules 2021 May 22;26(11). Epub 2021 May 22.

Guangdong Provincial Key Laboratory of Pharmaceutical Bioactive Substances, School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China.

Maca () has emerged as a popular functional plant food because of its medicinal properties and nutritional value. Macamides, as the exclusively active ingredients found in maca, are a unique series of non-polar, long-chain fatty acid -benzylamides with multiple bioactivities such as antifatigue characteristics and improving reproductive health. In this study, a new kind of macamide, -benzyl eicosapentaenamide (NB-EPA), was identified from maca. We further explore its potential neuroprotective role in hypoxic-ischemic brain injury. Our findings indicated that treatment with biosynthesized NB-EPA significantly alleviates the size of cerebral infarction and improves neurobehavioral disorders after hypoxic-ischemic brain damage in neonatal mice. NB-EPA inhibited the apoptosis of neuronal cells after ischemic challenge. NB-EPA improved neuronal cell survival and proliferation through the activation of phosphorylated AKT signaling. Of note, the protective property of NB-EPA against ischemic neuronal damage was dependent on suppression of the p53-PUMA pathway. Taken together, these findings suggest that NB-EPA may represent a new neuroprotectant for newborns with hypoxic-ischemic encephalopathy.
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http://dx.doi.org/10.3390/molecules26113108DOI Listing
May 2021

Dissipative Particle Dynamics Study on Interfacial Properties of Symmetric Ternary Polymeric Blends.

Polymers (Basel) 2021 May 8;13(9). Epub 2021 May 8.

State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.

We investigated the interfacial properties of symmetric ternary // and // polymeric blends by means of dissipative particle dynamics (DPD) simulations. We systematically analyzed the effects of composition, chain length, and concentration of the copolymers on the interfacial tensions, interfacial widths, and the structures of each polymer component in the blends. Our simulations show that: (i) the efficiency of the copolymers in reducing the interfacial tension is highly dependent on their compositions. The triblock copolymers are more effective in reducing the interfacial tension compared to that of the diblock copolymers at the same chain length and concentration; (ii) the interfacial tension of the blends increases with increases in the triblock copolymer chain length, which indicates that the triblock copolymers with a shorter chain length exhibit a better performance as the compatibilizers compared to that of their counterparts with longer chain lengths; and (iii) elevating the triblock copolymer concentration can promote copolymer enrichment at the center of the interface, which enlarges the width of the phase interfaces and reduces the interfacial tension. These findings illustrate the correlations between the efficiency of copolymer compatibilizers and their detailed molecular parameters.
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http://dx.doi.org/10.3390/polym13091516DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8125886PMC
May 2021

Surface Acoustic Wave DMMP Gas Sensor with a Porous Graphene/PVDF Molecularly Imprinted Sensing Membrane.

Micromachines (Basel) 2021 May 12;12(5). Epub 2021 May 12.

School of Software and Communication, Tianjin Sino-German University of Applied Sciences, Tianjin 300350, China.

In this paper, surface acoustic wave (SAW) sensors containing porous graphene/PVDF (polyvinylidene fluoride) molecularly imprinted sensitive membrane for DMMP gas detection were investigated. A 433 MHz ST-cut quartz SAW resonator was used to convert gas concentration changes into frequency shifts by the sensors. The porous graphene/PVDF film was fabricated on the sensor's surface by using the tape-casting method. DMMP molecules were adsorbed on the porous structure sensing film prepared by the 2-step method to achieve the specific recognition effect. The sensitivity of the sensor could reach -1.407 kHz·ppm. The response time and recovery time of the SAW sensor with porous graphene/PVDF sensing membrane were about 4.5 s and 5.8 s at the concentration of 10 ppm, respectively. The sensor has good anti-interference ability to most gases in the air.
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http://dx.doi.org/10.3390/mi12050552DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8152042PMC
May 2021

Corrigendum to "Rational design of a fluorescent probe for the detection of LAP and its application in drug-induced liver injury" [Spectrochim. Acta A Mol. Biomol. Spectrosc. 251 (2021) 119362].

Spectrochim Acta A Mol Biomol Spectrosc 2021 May 29;260:119921. Epub 2021 May 29.

State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China. Electronic address:

The purpose of this corrigendum to the published work by the author Liu et al. (2021) is to correct the wrong use of Figures during the proof.
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http://dx.doi.org/10.1016/j.saa.2021.119921DOI Listing
May 2021

Power coupling losses for misaligned and mode-mismatched higher-order Hermite-Gauss modes.

Opt Lett 2021 Jun;46(11):2694-2697

This paper analytically and numerically investigates misalignment and mode-mismatch-induced power coupling coefficients and losses as a function of Hermite-Gauss (HG) mode order. We show that higher-order HG modes are more susceptible to beam perturbations when, for example, coupling into optical cavities: the misalignment and mode-mismatch-induced power coupling losses scale linearly and quadratically with respect to the mode indices, respectively. As a result, the mode-mismatch tolerance for the ${{\rm HG}_{3,3}}$ mode is reduced to a factor of 0.28 relative to the currently used ${{\rm HG}_{0,0}}$ mode. This is a potential hurdle to using higher-order modes to reduce thermal noise in future gravitational-wave detectors.
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http://dx.doi.org/10.1364/OL.426999DOI Listing
June 2021

Investigation of the association between ten pathogens causing sexually transmitted diseases and high-risk human papilloma virus infection in Shanghai.

Mol Clin Oncol 2021 Jul 9;15(1):132. Epub 2021 May 9.

Clinical Laboratory, Zhongshan Hospital Affiliated to Fudan University Wusong Hospital, Shanghai 200940, P.R. China.

Cervical cancer, one of the high-incidence female malignant tumors, has predominated in recent years. Persistent infection with high-risk human papillomavirus (HR-HPV) is the main cause of cervical cancer. Studies have shown that infection with certain sexually transmitted disease (STD) pathogens increases the risk of persistent infection with HR-HPV and is a high-risk factor for cervical cancer. In the present study, cervical specimens were collected for Thinprep cytology test detection, while DNA of cervical cells was extracted for HPV genotyping and detection of 10 STD pathogens, including , (CT), , (Uup)1, Uup3, Uup6, Uup14, (Mh), (Mg) and herpes simplex virus II. Significant differences were observed between CT, Mh and Mg infections and HR-HPV infection (P<0.05). In addition, CT, Uup3, Uup6 and Mh infections were associated with HR-HPV infection (odds ratio >1; P<0.05). In the comparison of Uup3, Uup6 and Mg infections between the cervical intraepithelial neoplasia (CIN) group and the control group, statistically significant differences were observed (P<0.05). In conclusion, the incidences of CT, Mh and Mg infections were similar with HR-HPV infection. CT, Uup6, Mh and Mg infections were risk factors for HR-HPV infection. Finally, Uup3, Uup6 and Mg were risk factors of CIN.
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http://dx.doi.org/10.3892/mco.2021.2294DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8138855PMC
July 2021

All-trans-retinoic acid restores CD4+ T cell response after sepsis by inhibiting the expansion and activation of myeloid-derived suppressor cells.

Mol Immunol 2021 May 26;136:8-15. Epub 2021 May 26.

Department of Trauma Surgery, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, China. Electronic address:

Background: Patients are susceptible to immunosuppression in late-stage of sepsis, in which myeloid-derived suppressor cells (MDSCs) is an important contributor. This study aims to investigate whether all-trans-retinoic acid (ATRA), which has been proved to inhibit MDSCs generation in cancer, will ameliorate sepsis-induced immuno-suppression through modulating MDSCs.

Methods: A clinically relevant "two-hit'' model of sepsis, the cecal ligation and puncture (CLP) model and secondary pneumonia model, were established in mice. The effects of ATRA on the mortality, the bacterial burden, the expansion and activity of CLP-induced MDSCs, as well as the function of CD4+ T cells were evaluated.

Results: In CLP model, ATRA was found to reduce frequency of MDSCs in spleen of mice and inhibit activity of MDSCs by regulating the generation and activity of arginase-1 and iNOS, and the secretion of immune-supressive cytokines. ATRA administration eventually reduced mortality of secondary infection by Legionella pneumophila in CLP-surviving mice, which might be associated with the restoration of CD4+ T cells proliferating and secreting activity.

Conclusion: ATRA can restore CD4+ T cells dysfunction in sepsis by modulating the expansion and function of MDSCs and therefore provides a potential therapy that targets the immunosuppressive state of sepsis.
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http://dx.doi.org/10.1016/j.molimm.2021.04.025DOI Listing
May 2021

Hypoxia and pH co-triggered oxidative stress amplifier for tumor therapy.

Eur J Pharmacol 2021 May 25;905:174187. Epub 2021 May 25.

CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety and CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China, Beijing, 100190, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Research Unit of Nanoscience and Technology, Chinese Academy of Medical Sciences, Beijing, 100021, PR China. Electronic address:

To keep fast proliferation, tumor cells are exposed to higher oxidative stress than normal cells and they upregulate the amount of some antioxidants such as glutathione (GSH) against reactive oxygen species to maintain the balance. This phenomenon is severe in hypoxic tumor cells. Although researchers have proposed a series of treatment strategies based on regulating the intracellular reactive oxygen species level, few of them are related to the hypoxic tumor. Herein, a novel organic compound (PLC) was designed by using lysine as a bridge to connect two functional small molecules, a hypoxia-responsive nitroimidazole derivative (pimonidazole) and a pH-responsive cinnamaldehyde (CA) derivative. Then, the oxidative stress amplifying ability of PLC in hypoxic tumor cells was evaluated. The acidic microenvironment of tumor can trigger the release of CA to produce reactive oxygen species. Meanwhile, large amount of nicotinamide adenine dinucleotide phosphate (NADPH) can be consumed to decrease the synthesis of GSH during the bio-reduction process of the nitro group in PLC under hypoxic conditions. Therefore, the lethal effect of CA can be amplified for the decrease of GSH. Our results prove that this strategy can significantly enhance the therapeutic effect of CA in the hypoxic tumor cells.
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http://dx.doi.org/10.1016/j.ejphar.2021.174187DOI Listing
May 2021

Signature based on metabolic-related gene pairs can predict overall survival of osteosarcoma patients.

Cancer Med 2021 May 28. Epub 2021 May 28.

Department of Orthopaedic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China.

Background: Osteosarcoma is a tumour of malignant origin in children and adolescents. Recent progression indicates that it is necessary to develop new therapies to improve the patient's prognosis rather than strengthen anti-tumour chemotherapy. Researchers recently realised that cancer is a kind of disease with a metabolic disorder, and metabolic reprogramming is becoming a new cancer hallmark. Hence, our study's primary purpose is to explore the value of genes related to osteosarcoma metabolism.

Methods: From public databases, three osteosarcoma datasets with adequate clinical information were obtained. Besides, the IMvigor dataset through the 'IMvigor' package as a supplement was downloaded, the metabolic-related genes were identified, and these genes were used to construct the metabolic-related gene pairs (MRGP). Based on the prognosis-related MRGP, two molecular subtypes were identified. There are significant differences in the metabolic characteristics between the two molecular subtypes. Subsequently, the MRGP signature is constructed using the least absolute shrinkage and selection operator regression method. Finally, use SubMap analysis to evaluate the response of patients in the MRPG signature group to immunotherapy.

Results: The MRGP signature can reliably predict overall survival in patients with osteosarcoma. The MRGP signature is also associated with osteosarcoma patients' metastatic status and can be used for subsequent risk classification of metastatic patients. The immunotherapy is more likely to benefit the patients in the MRGP low-risk group.

Conclusion: Metabolic-related gene pairs signature can assess the prognosis of patients with osteosarcoma.
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http://dx.doi.org/10.1002/cam4.3984DOI Listing
May 2021

Influence of low tumor content on tumor mutational burden estimation by whole-exome sequencing and targeted panel sequencing.

Clin Transl Med 2021 May;11(5):e415

Department of In Vitro Diagnostic Reagent, National Institutes for Food And Drug Control (NIFDC), Beijing, China.

Background: Tumor mutational burden (TMB) is a promising biomarker for stratifying patient subpopulation who would benefit from immune checkpoint blockade (ICB) therapies. Although great efforts have been made for standardizing TMB measurement, mutation calling and TMB quantification can be challenging in samples with low tumor content including liquid biopsies. The effect of varying tumor content on TMB estimation by different assay methods has never been systematically investigated.

Method: We established a series of reference standard DNA samples derived from 11 pairs of tumor-normal matched human cell lines across different cancer types. Each tumor cell line was mixed with its matched normal at 0% (control), 1%, 2%, 5%, and 10% mass-to-mass ratio to mimic the clinical samples with low tumor content. TMB of these reference standards was evaluated by both ∼1000× whole-exome sequencing (wesTMB) and targeted panel sequencing (psTMB) at four different vendors. Both regression and classification analyses of TMB were performed for theoretical investigation and clinical practice purposes.

Results: Linear regression model was established that demonstrated in silico psTMB determined by regions of interest (ROI) as a great representative of wesTMB based on TCGA dataset. It was also true in our reference standard samples as the predicted psTMB interval based on the observed wesTMB captured the intended 90% of the in silico psTMB values. Although ∼1000× deep WES was applied, reference standard samples with less than 5% of tumor proportions are below the assay limit of detection (LoD) of wesTMB quantification. However, predicted wesTMB based on observed psTMB accurately classify (>0.97 AUC) for TMB high and low patient stratification even in samples with 2% of tumor content, which is more clinically relevant, as TMB determination should be a qualitative assay for TMB high and low patient classification. One targeted panel sequencing vendor using an optimized blood psTMB pipeline can further classify TMB status accurately (>0.82 AUC) in samples with only 1% of tumor content.

Conclusions: We developed a linear model to establish the quantitative correlation between wesTMB and psTMB. A set of DNA reference standards was produced in aid to standardize TMB measurements in samples with low tumor content across different targeted sequencing panels. This study is a significant contribution aiming to harmonize TMB estimation and extend its future application in clinical samples with low tumor content including liquid biopsy.
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http://dx.doi.org/10.1002/ctm2.415DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8102856PMC
May 2021