Low-Temperature Oxidation of Methane on Rutile TiO2(110): Identifying the Role of Surface Oxygen Species.

Understanding the microkinetic mechanism underlying photocatalytic oxidative methane (CH4) conversion is of significant importance for the successful design of efficient catalysts. Herein, CH4 photooxidation has been systematically investigated on oxidized rutile(R)-TiO2(110) at 60 K. Under 355 nm irradiation, the C-H bond activation of CH4 is accomplished by the hole-trapped dangling OTi- center rather than the hole-trapped Ob- center via the Eley-Rideal reaction pathway, producing movable CH3• radicals. Subsequently, movable CH3• radicals encounter an O/OH species to form CH3O/CH3OH species, which could further dissociate into CH2O under irradiation. However, the majority of the CH3• radical intermediate is ejected into a vacuum, which may induce radical-mediated reactions under ambient conditions. The result not only advances our knowledge about inert C-H bond activation but also provides a deep insight into the mechanism of photocatalytic CH4 conversion, which will be helpful for the successful design of efficient catalysts.

An effective two-stage NMBzA-induced rat esophageal tumor model revealing that the FAT-Hippo-YAP1 axis drives the progression of ESCC.

Rat model of N-nitrosomethylbenzylamine (NMBzA)-induced esophageal squamous cell carcinoma (ESCC) is routinely used to study ESCC initiation, progression and new therapeutic strategies. However, the model is time-consuming and malignant tumor incidences are low. Here, we report the usage of multi-kinase inhibitor sorafenib as a tumor promoter to establish an efficient two-stage NMBzA-induced rat ESCC carcinogenesis model, resulting in increments of tumor incidences and shortened tumor formation times. By establishing the model and applying whole-genome sequencing, we discover that benign papillomas and malignant ESCCs harbor most of the "driver" events found in rat ESCCs (e.g. recurrent mutations in Ras family, the Hippo and Notch pathways and histone modifier genes) and the mutational landscapes of rat and human ESCCs overlap extensively. We generate tumor cell lines derived from NMBzA-induced papillomas and ESCCs, showing that papilloma cells retain more characteristics of normal epithelial cells than carcinoma cells, especially their exhibitions of normal rat cell karyotypes and inabilities of forming tumors in immunodeficient mice. Three-dimensional (3-D) organoid cultures and single cell RNA sequencing (scRNA-seq) indicate that, when compared to control- and papilloma-organoids, ESCC-organoids display salient abnormalities at tissue and single-cell levels. Multi-omic analyses indicate that NMBzA-induced rat ESCCs are accompanied by progressive hyperactivations of the FAT-Hippo-YAP1 axis and siRNA or inhibitors of YAP1 block the growth of rat ESCCs. Taken together, these studies provide a framework of using an effective rat ESCC model to investigate multilevel functional genomics of ESCC carcinogenesis, which justify targeting YAP1 as a therapeutic strategy for ESCC.

Analysis of the Genetic Model of the Extremely Narrow Channel Shallow Water Delta in DL-A Oilfield, Bohai Bay Basin.

In recent years, the oil and gas reserves discovered in shallow water deltas in China have continued to grow. The research on shallow water delta deposition models and depositional genesis is becoming more and more mature. In this latest discovery, a unique type of extremely narrow channel shallow water delta deposit was found at the top of the V oil group in the lower part of the Minghuazhen Formation during the Neogene period at DL-A Oilfield, located in the Bohai Bay Basin. The width of most single channels in this deposit measures between 100 and 200m, which is relatively rare and differs from existing research. To better understand this unique narrow channel shallow water delta deposit, a range of analysis methods were conducted including trace element analysis, major element analysis, grain size analysis, core observation, casting thin section observation, 3D seismic analysis, and other methods. These analyses were used to determine the sedimentary environment and sedimentary genesis of the deposit in the study area. The results show the following: (1) The top of the V oil group in the lower part of Minghuazhen Formation was deposited with a strong oxidizing environment. In the early stage, the climate was dry and cold, and gradually changed to warm and humid in the late stage. (2) Due to the frequent exposure to the surface, obvious weathered surfaces and sedimentary discontinuities were observed on the cores; the particle size analysis shows that the lamina types developed in the study area are clastic-clay laminae and clay-clastic laminae, which are mostly developed in shallow lakes area. (3) Observations of cores and thin sections also indicated that the hydrodynamic conditions frequently changed in the study area, alternating between strong and weak hydrodynamic conditions in a short period due to the alternating occurrence of flood and dry periods during the rainy season. Weak hydrodynamic conditions and slow water flow result in insufficient undercutting and sidecutting of rivers. The alternating occurrence of flood periods and dry periods has led to the development of crevasse splays and frequent river channel diversions, resulting in the inability of long-term stable development of the river channel. Besides, the change of water level has also led to the rebuilding of the river. Therefore, the multiple effects led to the formation of an extremely narrow channel shallow water delta. The accuracy of the sedimentary model is verified by a comparative study of the Shaliu River and Buha River in the modern Qinghai Lake. The new extremely narrow channels deposition model proposed this time further improves the deposition theory. At the same time, the modern depositional characteristics of the Shaliu River and Buha River also reveal the reservoir deposition between channels that cannot be distinguished by seismic data, providing guidance for the development of oil and gas in the study area.

Effect and mechanism of HMG-CoA reductase inhibitor on the improvement of elderly essential hypertension-induced vascular endothelial function impairment based on the JAK/STAT pathway.

OBJECTIVE: Our research was designed to figure out the influence and mechanism of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor on the improvement of elderly essential hypertension-induced vascular endothelial function impairment based on the JAK/STAT pathway. METHODS: Eighty-six elderly patients with essential hypertension were randomized into a control group (oral Amlodipine Besylate Tablets) and an observation group (oral Amlodipine Besylate Tablets + HMG-CoA reductase inhibitor atorvastatin calcium). Patients in both groups were treated with the drug for 12 weeks. Blood pressure, serum levels of inflammatory factors, and vascular endothelial function indicators, and levels of blood lipids were measured. The modeled rats were treated with atorvastatin calcium and a JAK/STAT pathway inhibitor (AG490), and the levels of cardiac function-related indices, left ventricular mass index, lipid levels, serum inflammatory factors and vascular endothelial function-related indices were detected in each group. RESULTS: HMG-CoA reductase inhibitor improved blood pressure levels, lipid levels, serum inflammatory factor levels and cardiac function in elderly patients with essential hypertension. Both HMG-CoA reductase inhibitor and AG490 improved blood pressure levels, lipid levels, serum inflammatory factor levels and cardiac function in SHR rats. Both HMG-CoA reductase inhibitor and AG490 decreased p-JAK2/JAK2 and p-STAT3/STAT3 expression levels. CONCLUSION: Our study demonstrates that HMG-CoA reductase inhibitor improves elderly essential hypertension-induced vascular endothelial function impairment by blocking the JAK/STAT pathway.

Selective nucleophilic α-C alkylation of phenols with alcohols via Ti=Cα intermediate on anatase TiO2 surface.

C-C bond forming reaction by alkylation of aryl rings is a main pillar of chemistry in the production of broad portfolios of chemical products. The dominant mechanism proceeds via electrophilic substitution of secondary and tertiary carbocations over acid catalysts, forming multiple aryl alkylation products non-selectively through all secondary and tertiary carbons in the alkyl chains but producing little α-C alkylation products because primary carbocations are poorly stable. Herein, we report that anatase TiO2 (TiO2-A) catalyzes nucleophilic α-C alkylation of phenols with alcohols in high selectivity to simply linear alkylphenols. Experimental and computational studies reveal the formation of Ti=C- bond with the α-carbon of the alkyl group at oxygen vacancies of the TiO2-A surface. The subsequent α-C alkylation by selective substitution of phenol ortho-C-H bond is verified by deuterium exchanged substrate and DFT calculations.

Dinitrogen Activation by Heteronuclear Bimetallic Cluster Anion FeV- in the Gas Phase.

Nitrogen activation is a significant but difficult project in the chemical area. Photoelectron spectroscopy (PES) and calculated results are used to investigate the reaction mechanism of the heteronuclear bimetallic cluster FeV- toward N2 activation. The results clearly show that N2 can be fully activated by FeV- at room temperature, forming the FeV(µ2-N)2- complex with the totally ruptured N≡N bond. Electronic structure analysis reveals that the activation of N2 by FeV- is achieved by the electron transfer of bimetallic atoms and electron back-donation to the metal core, which demonstrates that heteronuclear bimetallic anionic clusters are very important to nitrogen activation. This study provides important information for the rational design of synthetic ammonia catalysts.

Capturing Hydrogen Radicals by Neutral Metal Hydroxides.

Capturing the hydrogen radical is of central importance in various systems ranging from catalysis to biology to astronomy, but it has been proven to be challenging experimentally because of its high reactivity and short lifetime. Here, neutral MO3H4 (M = Sc, Y, La) complexes were characterized by size-specific infrared-vacuum ultraviolet spectroscopy. All these products were determined to be the hydrogen radical adducts in the form of H•M(OH)3. The results indicate that the addition of the hydrogen radical to the M(OH)3 complex is both thermodynamically exothermic and kinetically facile in the gas phase. Moreover, the soft collisions in the cluster growth channel with the helium expansion were found to be demanded for the formation of H•M(OH)3. This work highlights the pivotal roles played by the soft collisions in the formation of hydrogen radical adducts and also opens new avenues toward the design and chemical control of compounds.

Solvent-mediated precipitating synthesis and optical properties of polyhydrido Cu13 nanoclusters with four vertex-sharing tetrahedrons.

Structurally defined metal nanoclusters facilitate mechanism studies and promote functional applications. However, precisely constructing copper nanoclusters remains a long-standing challenge in nanoscience. Developing new efficient synthetic strategies for Cu nanoclusters is highly desirable. Here, we propose a solvent-mediated precipitating synthesis (SMPS) to prepare Cu13H10(SR)3(PPh3)7 nanoclusters (H-SR = 2-chloro-4-fluorobenzenethiol). The obtained Cu13 nanoclusters are high purity and high yield (39.5%, based on Cu atom), proving the superiority of the SMPS method. The Cu13 nanoclusters were comprehensively studied via a series of characterizations. Single crystal X-ray crystallography shows that the Cu13 nanoclusters contain a threefold symmetry axis and the Cu13 kernel is protected by a monolayer of ligands, including PPh3 and thiolates. Unprecedentedly, the aesthetic Cu13 kernel is composed of four vertex-sharing tetrahedrons, rather than the common icosahedral or cuboctahedral M13. The intramolecular π⋯π interactions between thiolates and PPh3 on the surface contribute to the stable configuration. Furthermore, electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) revealed the existence of ten hydrides, including four types of hydrides. Density functional theory (DFT) calculations without simplifying the ligands simulated the location of the 10 hydrides in the crystal structure. Additionally, the steady-state ultraviolet-visible absorption and fluorescence spectra of the Cu13 nanoclusters exhibit unique optical absorbance and photoluminescence. The ultrafast relaxation dynamics were also studied via transient absorption spectroscopy, and the three decay components are attributed to the relaxation pathways of internal conversion, structural relaxation and radiative relaxation. This work provides not only a novel SMPS strategy to efficiently synthesize Cu13 nanoclusters, but also a better insight into the structural characteristics and optical properties of the Cu nanoclusters.

Spectroscopic Identification of the Dinitrogen Fixation and Activation by Metal Carbide Cluster Anions PtCn- (n = 4-6).

Nitrogen fixation is confronted with great challenges in the field of chemistry. Herein, we report that single metal carbides PtCn- and PtCnN2- (n = 4-6) are indispensable intermediates in the process of nitrogen fixation by mass spectrometry coupled with anionic photoelectron spectroscopy, quantum chemical calculations, and simulated density-of-state spectra. The most stable isomers of these cluster anions are characterized to have linear chain structures. The fixation and activation of dinitrogen are facilitated by the charge transfer from Pt and Cn to N2. The significance of π back-donation of the 5d orbital of the Pt atom to the antibonding π orbits of N2 for dinitrogen fixation and activation is discussed in detail. This study not only provides a theoretical basis at the molecular level for the activation of dinitrogen by mononuclear metal carbide clusters but also provides a new paradigm for dinitrogen fixation.

Cerebrospinal fluid drainage and chronic hydrocephalus in aneurysmal subarachnoid hemorrhage patients with intraventricular hemorrhage.

Background: Patients with intraventricular hemorrhage (IVH) are at a higher risk of developing hydrocephalus and often require external ventricular drainage or long-term ventriculoperitoneal shunt surgery. Objective: To investigate whether cerebrospinal fluid drainage in patients with IVH due to aneurysmal subarachnoid hemorrhage (aSAH) reduces the incidence of chronic hydrocephalus. Method: A retrospective analysis was conducted on patients with aSAH treated at our hospital between January 2020 and December 2022. The first analysis compared patients with and without IVH, while the second analysis compared IVH patients with and without chronic hydrocephalus. The third analysis compared IVH patients who underwent in different drainage methods which is lumbar drainage (LD) or external ventricular drainage (EVD). The primary outcome measure was the incidence of chronic hydrocephalus. Result: Of the 296 patients hospitalized with aSAH, 108 (36.5%) had IVH, which was associated with a significantly higher incidence of chronic hydrocephalus compared to patients without IVH (49.1% vs. 16.5%, p < 0.001). Multivariate logistic regression analysis showed that IVH was independently associated with the formation of chronic hydrocephalus (OR: 3.530, 95% CI: 1.958-6.362, p < 0.001). Among the 108 IVH patients, 53 (49.1%) developed chronic hydrocephalus. Multivariate logistic regression analysis revealed that the Hunt Hess grade at admission (OR: 3.362, 95% CI: 1.146-9.863, p = 0.027) and postoperative cerebrospinal fluid drainage (OR: 0.110, 95% CI: 0.036-0.336, p < 0.001) were independent risk factors for the development of chronic hydrocephalus in IVH patients. Among all IVH patients who underwent cerebrospinal fluid drainage, 45 (75%) received continuous lumbar puncture drainage, and 15 (25%) received external ventricular drainage. Univariate analysis did not show a statistically significant difference between the two groups in terms of postoperative chronic hydrocephalus (p = 0.283). However, multivariate logistic regression analysis suggested that the drainage methods of LD and EVD might be associated with the development of chronic hydrocephalus. Conclusion: The presence of IVH increases the risk of chronic hydrocephalus in patients with aSAH, and postoperative cerebrospinal fluid drainage appears to reduce this risk. The specific effects of lumbar puncture drainage and ventricular drainage on the incidence of chronic hydrocephalus require further investigation.

Photocatalytic Oxidative Dehydrogenation of Propane for Selective Propene Production with TiO2.

Oxidative dehydrogenation of propane (ODHP) as an exothermic process is a promising method to produce propene (C3H6) with lower energy consumption in chemical industry. However, the selectivity of the C3H6 product is always poor because of overoxidation. Herein, the ODHP reaction into C3H6 on a model rutile(R)-TiO2(110) surface at low temperature via photocatalysis has been realized successfully. The results illustrate that photocatalytic oxidative dehydrogenation of propane (C3H8) into C3H6 can occur efficiently on R-TiO2(110) at 90 K via a stepwise manner, in which the initial C-H cleavage occurs via the hole coupled C-H bond cleavage pathway followed by a radical mediated C-H cleavage to the C3H6 product. An exceptional selectivity of ∼90% for C3H6 production is achieved at about 13% propane conversion. The mechanistic model constructed in this study not only advances our understanding of C-H bond activation but also provides a new pathway for highly selective ODHP into C3H6 under mild conditions.

The Role of Redox-Inactive Metals in Modulating the Redox Potential of the Mn4CaO4 Model Complex.

Photosynthetic oxygen-evolving center (OEC), the "engine of life", is a unique Mn4CaO5 cluster catalyzing the water oxidation. The role of redox-inactive component Ca2+, which can only be functionally replaced by Sr2+ in a biological environment, has been under debate for a long time. Recently, its modulating effect on the redox potential of native OEC and artificial structural OEC model complex has received great attention, and linear relationship between the potential and the Lewis acidity of the redox-inactive metal has been proposed for the MMn3O4 model complex. In this work, the modulating effect has been studied in detail using the Mn4CaO4 model complex, which is the closest structural model to OEC to date and has a similar redox potential at the S1-S2 transition. We found the redox-inactive metal only has a weak modulating effect on the potential, which is comparable in strength to that of the ligand environments. Meanwhile, the net charge of the complex, which could be changed along with the redox-inactive metal, has a high impact on the potential and can be unified by protonation, deprotonation, or ligand modification. Although the modulating effect of the redox-inactive metal is not very strong, the linear relationship between the potential and the Lewis acidity is still valid for Mn4MO4 complexes. Our results of strong modulating effects for net charge and weak modulating effects for redox-inactive metal fit with the previous experimental observations on Mn4MO4 (M = Ca2+, Y3+, and Gd3+) model complexes, and suggest that Ca2+ can be structurally and electrochemically replaced with other metal cations, together with proper ligand modifications.

Aerosol mass spectrometry of neutral species based on a tunable vacuum ultraviolet free electron laser.

A vacuum ultraviolet free electron laser (VUV-FEL) photoionization aerosol mass spectrometer (AMS) has been developed for online measurement of neutral compounds in laboratory environments. The aerosol apparatus is mainly composed of a smog chamber and a reflectron time-of-flight mass spectrometer (TOF-MS). The indoor smog chamber had a 2 m3 fluorinated ethylene propylene film reactor placed in a temperature- and humidity-controlled room, which was used to generate the aerosols. The aerosols were sampled via an inlet system consisting of a 100 µm orifice nozzle and aerodynamic lenses. The application of this VUV-FEL AMS to the α-pinene ozonolysis under different concentrations reveals two new compounds, for which the formation mechanisms are proposed. The present findings contribute to the mechanistic understanding of the α-pinene ozonolysis in the neighborhood of emission origins of α-pinene. The VUV-FEL AMS method has the potential for chemical analysis of neutral aerosol species during the new particle formation processes.

Sensitive detection of glyoxal by cluster-mediated CH2Br2+ chemical ionization time-of-flight mass spectrometry.

Direct and rapid analysis of glyoxal by soft ionization mass spectrometry remains a great challenge due to its low ionization efficiency in existing soft ionization techniques, such as proton transfer reaction (PTR) and photoionization (PI). In this work, we developed a new VUV lamp-based cluster-mediated CH2Br2+ chemical ionization (CMCI) source for time-of-flight mass spectrometry (TOFMS), which was accomplished by employing photoionization-generated CH2Br2+ as the reactant ion and co-sampling of glyoxal with high-concentration ethanol (EtOH). The signal intensity of glyoxal could be enhanced by more than 2 orders of magnitude by generating protonated cluster ion [Glx·EtOH·H]+. Density function theory (DFT) calculations was performed to obtain the most stable structure of neutral glyoxal-ethanol cluster and confirm that the ionization energy (IE) of glyoxal-ethanol cluster was significantly lower than that of glyoxal and CH2Br2 molecules, which makes it possible for effective ionization of glyoxal. The ionization efficiency of glyoxal could be dramatically enhanced via ion-molecule reaction between CH2Br2+ and glyoxal-ethanol cluster, as larger ionization cross section of glyoxal-ethanol cluster than glyoxal molecule might be achieved. The cluster-mediated signal enhanced effect was also verified by using other alcohols, such as methanol and isopropanol. Consequently, the limit of quantitation (LOQ, S/N = 10) down to 0.17 ppbv for gas-phase glyoxal was achieved. The analytical capacity of this system was demonstrated by trace analysis of glyoxal in food contact papers, exhibiting new insights and wide potentials of chemical ionization and photoionization mass spectrometry for VOCs measurement with higher sensitivity and wider detectable sample range.

Spectroscopic Characterization of the Synergistic Mechanism of Ruthenium-Lithium Hydrides for Dinitrogen Cleavage.

Elucidating the role of alkali/alkaline earth metal hydrides in dinitrogen activation remains an important and challenging goal for spectroscopic studies of bulk systems, because their spectral signatures are often masked by the collective effects. Herein, mass-selected photoelectron velocity-map imaging spectroscopic and quantum chemical calculation techniques are utilized to explore the promotion mechanism of LiH in the Ru-based catalysts toward N2 activation. The RuHN2- anion is determined to be a N2-tagged complex. In contrast, the RuHN2(LiH)n- (n = 1 and 2) anions are characterized to have N≡N bond-cleaved ring structures. These observations indicate that the complexation of LiH to RuH- significantly facilitates N≡N bond cleavage. Theoretical analyses show that the synergy between Ru and LiH efficiently lowers the energy barrier of N≡N bond cleavage. These findings clarify the pivotal roles played by the LiH species in the transition metal catalysts for N2 activation and have important practical implications for the prospective design of high-performance catalysts via metal tuning strategies.

Hydrogen Production on Pt/TiO2: Synergistic Catalysis between Pt Clusters and Interfacial Adsorbates.

Understanding the mechanism of hydrogen (H2) formation from the conversion of water (H2O) and renewables on TiO2 surfaces with cocatalysts via either photocatalysis or other catalytic processes is of significant importance to the successful design of efficient catalysts. Herein, we have investigated H2 production from H2O, CH3OH, and C2H5OH on a Pt cluster covered rutile (R)-TiO2(110) surface (Ptclut/R-TiO2(110)) to address the mechanism of H2 production. Experimental results demonstrate that surface adsorbates not only help H atom diffusion on Ptclut/R-TiO2(110) but also take part in H2 production directly. Further density functional theory (DFT) calculations suggest that H2 production on Ptclut/R-TiO2(110) occurs via a synergistic catalysis process between Pt clusters and interfacial adsorbates rather than a recombination reaction of H atoms on Pt clusters. This work provides new insight into H2 production from H2O and renewables with Pt/TiO2 catalysts, which may be applicable to H2 production on other Pt cluster deposited metal oxide catalysts.

Ligand-Induced Tuning of the Electronic Structure of Rhombus Tetraboron Cluster.

A neutral boron carbonyl complex B4 (CO)3 is generated in the gas phase and is characterized by infrared plus vacuum ultraviolet (IR+VUV) two-color ionization spectroscopy and quantum chemical calculations. The complex is identified to have a planar C2v structure with three CO ligands terminally coordinated to a rhombus B4 core. It has a closed-shell singlet ground state that correlates to an excited state of B4 . Bonding analyses on B4 (CO)3 as well as the previously reported B4 and B4 (CO)2 indicate that the electronic structure of rhombus tetraboron cluster changes from a close-shell singlet to an open-shell singlet in B4 (CO)2 and to a close-shell singlet in B4 (CO)3 , demonstrating that the electronic structures of boron clusters can be effectively tuned via sequential CO ligand coordination.

Silylium ion migration dominated hydroamidation of siloxy-alkynes.

The mechanism of silver-catalyzed hydroamidation of siloxy-alkynes reaction remains controversial. Using density functional theory (DFT), we revealed that the reaction takes place through a silylium ion migration mediated hydroamination (SMH) pathway. The SMH pathway goes through two steps, the first step is Ag+ promoted proton and silylium ion exchange between siloxy-alkynes and amide, leading to ketene and silyl-imines, the second step is Ag+ catalyzed nucleophilic addition between ketene and silyl-imines, following with a silylium ion migration afford the final product. In this reaction, Ag+ activates the siloxy-alkyne into silylium ion (TIPS+) and silver-ketene through the p-π conjugate effect, the silylium ion then catalyzes the reaction. According to our calculation, the scopes of alkynes in this reaction may be extended to silyl-substituted ynamines or silyl-substituted ynamides. The scopes of amide may be extended into the p-π conjugate system such as diazoles, diazepines, etc. Our calculations also reveal a concise way to construct enamides through Ag+ catalyzed nucleophilic addition between substituted-ketenes and silyl-substituted p-π conjugate system.

Isoelectronic IrC3-, PtC3, and AuC3+ Clusters Featuring the Structural and Bonding Resemblance to OC3.

The IrC3- and PtC3- anions generated by laser vaporization were identified and characterized by gas-phase photoelectron spectroscopy and quantum-chemical calculations. The straight-chain structures with an MCCC (M = metal; C = carbon) connectivity are found for the isoelectronic IrC3-, PtC3, and AuC3+ clusters. Further elaborate analyses manifest the strikingly structural and bonding similarities between MC3-/0/+ clusters and OC3 revealed. This finding has broadened the notion of autogenic isolobality to the gas-phase clusters that contain Ir-, Pt, Au+, and C centers.

The expression of PHOX2B in bone marrow and peripheral blood predicts adverse clinical outcome in non-high-risk neuroblastoma.

Paired-like homeobox 2B (PHOX2B) is a highly sensitive and specific biomarker for diagnosing neuroblastoma, as well as detecting minimal residual disease in neuroblastoma. The clinical significance of PHOX2B expression in bone marrow (BM) and peripheral blood (PB) samples of newly diagnosed patients with very low-, low- and intermediate-risk neuroblastoma remains unknown, to the best of our knowledge. The expression level of PHOX2B in paired BM and PB samples of patients with newly diagnosed neuroblastoma was validated using reverse transcription-quantitative polymerase chain reaction (RTqPCR). Among the 132 patients, 26 exhibited a positive PHOX2B expression BM (19.7%) and 11 in PB (8.3%) samples. PHOX2B was highly expressed in BM and PB samples from patients aged <18 months, with International Neuroblastoma Risk Group Staging System stages M and MS, 1p loss of heterozygosity, and high levels of lactate dehydrogenase, serum ferritin and neuron-specific enolase (p < 0.05). In all eligible patients, the 2-year event-free survival (EFS) and overall survival (OS) rates were 94.7 ± 2.0% and 97.7 ± 1.3%, respectively. However, the 2-year EFS rates were significantly decreased to 76.9 ± 8.3% and 63.6 ± 14.5% in patients with a positive PHOX2B expression in BM and PB samples, respectively (p < 0.05). Similarly, the 2-year OS rates were also decreased to 88.5 ± 6.3% and 81.8 ± 11.6% in patients with a positive PHOX2B expression in BM and PB samples, respectively (p < 0.05). In conclusion, a positive PHOX2B expression in BM and PB samples at diagnosis had a strong adverse prognostic effect on patients with non-high-risk neuroblastoma.