Development and validation of a risk nomogram model for predicting peripheral neuropathy in patients with type 2 diabetes mellitus.

Objective: Diabetic peripheral neuropathy frequently occurs and presents severely in individuals suffering from type 2 diabetes mellitus, representing a significant complication. The objective of this research was to develop a risk nomogram for DPN, ensuring its internal validity and evaluating its capacity to predict the condition. Methods: In this retrospective analysis, Suqian First Hospital's cohort from January 2021 to June 2022 encompassed 397 individuals diagnosed with T2DM. A random number table method was utilized to allocate these patients into two groups for training and validation, following a 7:3 ratio. By applying univariate and multivariable logistic regression, predictive factors were refined to construct the nomogram. The model's prediction accuracy was assessed through metrics like the ROC area, HL test, and an analysis of the calibration curve. DCA further appraised the clinical applicability of the model. Emphasis was also placed on internal validation to confirm the model's dependability and consistency. Results: Out of 36 evaluated clinicopathological characteristics, a set of four, duration, TBIL, TG, and DPVD, were identified as key variables for constructing the predictive nomogram. The model exhibited robust discriminatory power, evidenced by an AUC of 0.771 (95% CI: 0.714-0.828) in the training cohort and an AUC of 0.754 (95% CI: 0.663-0.845) in the validation group. The congruence of the model's predictions with actual findings was corroborated by the calibration curve. Furthermore, DCA affirmed the clinical value of the model in predicting DPN. Conclusion: This research introduces an innovative risk nomogram designed for the prediction of diabetic peripheral neuropathy in individuals suffering from type 2 diabetes mellitus. It offers a valuable resource for healthcare professionals to pinpoint those at elevated risk of developing this complication. As a functional instrument, it stands as a viable option for the prognostication of DPN in clinical settings.

Removal of field-collected Microcystis aeruginosa in pilot-scale by a jet pump cavitation reactor.

Hydrodynamic cavitation has been investigated extensively in the field of water treatment in the last decade and a well-designed hydrodynamic cavitation reactor is critical to the efficient removal of algal and large-scale application. In this paper, a jet pump cavitation reactor (JPCR) is developed for the removal of cyanobacteria Microcystis aeruginos in a pilot scale. The results demonstrate that the photosynthetic activity of M. aeruginosa is greatly inhibited immediately after treatment in the JPCR, and the growth is also hindered after 3 days culture. Moreover, a high cell disruptions of M. aeruginosa is detected after treated by JPCR. The release of chlorophyll-a indicates that the JPCR caused serious rupture to M. aeruginosa cells. The plausible cell disruption mechanisms are proposed in accordance with a fluorescence microscope and scanning electron microscope. Then, the optimization of cell disruption efficiency is also investigated for various operating conditions. The results showed that the algal cell disruption efficiency is improved at higher inlet pressure and the cavitation stage between the unstable limited operation cavitation stage and stable limited operation cavitation stage. The effect and optimization of JPCR on algal reduction are highlighted. The results of the study promote the application of hydrodynamic cavitation on algal removal and provide strong support for JPCR application in algal removal.

Water jet as a novel technique for enamel drilling ex vivo.

To investigate the usage of a water jet for enamel drilling ex vivo, 210 individual extracted molars without lesions or fillings were collected. Then, the specimens were drilled by a water jet or a high-speed dental drill. The cavities of 50 teeth were reconstructed digitally by micro-computed tomography (micro-CT) to measure the height and width. The cavities of 10 teeth were longitudinally incised and their surfaces were observed by scanning electronic microscopy (SEM). After the cavities were filled, 50 fillings were vertically incised. The bonding interface between tooth and filling was observed by SEM. 50 teeth with fillings were stained in 0.1% rhodamine B solution, and then the dye penetration between tooth and filling was observed under the stereomicroscope and confocal laser scanning microscopy (CLSM). The bonding strength between enamel and filling of 50 teeth was simulated and predicted with finite element analysis (FEA). At 140-150 MPa and for 2-3 s, cavities were made with a depth of approximately 764 µm in each tooth. SEM showed the cavity surface in the water jet group had a more irregular concave and convex structure than that in the high-speed dental drill group. There was a trend that the microleakage and bonding width was smaller in the water jet group than in the high-speed dental drill group. FEA indicated that the stress on the resin surface was greater than on the enamel surface in the water jet group. Compared with the tooth drilled by a high-speed dental drill, the tooth drilled by a water jet gained better retention of the filling material and suffered less bonding strength on the enamel surface. Water jet drilling is effective for enamel drilling.

Molecular polarizabilities of some energetic compounds.

The dependence of sensitivity of an explosive on its molecular structure may be mainly attributed to the molecular deformability, which can be expressed by some characteristic parameters, resonance energy for aromatic an explosive, strain energy for a strained-ring or strained-cage explosive, large π-π separation energy for a large π-π linked-explosive, bond rotational energy barriers of C-NO2, N-NO2, O-NO2 for C-NO2, N-NO2, O-NO2 bond-based explosives, and so on. Molecular polarizability of an explosive is also an important molecular deformability index, which can be effectively used to compare impact sensitivities of explosive's isomers, isoelectronic species, and similar structures. Interestingly, comparing the molecular polarizabilities under external electric fields with different energy levels of isomeric N20(Ih) and N20(D3d) clusters and the Mo2N20 and Re2N20 complex compounds, it is found that there are different energy thresholds of significant molecular expansion.

Experimental study of the cavitation noise and vibration induced by the choked flow in a Venturi reactor.

In this paper, the cavitation performance and corresponding pressure pulsation, noise and vibration induced by the choked cavitating flow in a Venturi reactor are investigated experimentally under different cavitation conditions by using high-speed camera and high frequency sensors. Based on the instantaneous continuous cavitation images, the Proper Orthogonal Decomposition (POD), a tool to analyze the large-scale cavitation flow structure, is applied to investigate the choked cavitating flow dynamics. The POD results show that two mechanisms, re-entrant jet flow mechanism and shock wave mechanism, govern the shedding and collapse of cavitation cloud at different pressure ratios. These mechanisms contribute to the variation of pressure pulsation, noise and vibration at different pressure ratios. The pressure pulsation spectrum behaves differently in various cavitation regions induced by the choked cavitating flow. Due to the existence of low pressure in re-entrant region, the influence of high frequency fluctuation on pressure pulsation caused by re-entrant flow is small. Moreover, with the increase of pressure ratio, the induced noise and vibration intensity decreases gradually, then increases and reaches a maximum value. Finally, it drops to a low and stable level. Despite different inlet pressures, the intensity of cavitation noise and vibration reaches the maximum value at the same pressure ratio. Specifically, the FFT analysis of noise and vibration signals indicates that low frequency component prevails at small pressure ratio owing to the re-entrant jet mechanism, while high frequency component prevails at large pressure ratio owing to the shock wave mechanism. The relationship between the choked cavitation dynamics and the induced pressure pulsation, noise and vibration in the Venturi reactor is highlighted. The results can provide guidance for the optimal operation condition of the Venturi reactor for cavitation applications such as water treatment.

Anisotropic hydrogen bond structures and orientation dependence of shock sensitivity in crystalline 1,3,5-tri-amino-2,4,6-tri-nitrobenzene (TATB).

The orientation dependence of shock sensitivity in high explosive crystals was explored in this study. As a widely used wood explosive, 1,3,5-tri-amino-2,4,6-tri-nitrobenzene (TATB) is insensitive to thermal ignition and mechanical impact. Its typical anisotropic crystal structure suggests anisotropic shock sensitivity. Shockwaves were applied to an incised TATB crystal along three orthogonal directions using the multiscale shock technique (MSST) combined with the ReaxFF method to study the origin of anisotropic shock sensitivity. The physical and chemical responses of the TATB crystal during shock were investigated. The results show that the temperature, stress, volume compressibility, and decomposition rate of TATB are strongly dependent on the shockwave direction. In other words, the sensitivity of TATB to mechanical shock is strongly dependent on the crystal orientation. TATB is relatively sensitive along the directions parallel to the (001) crystal plane (X and Y directions) and is highly insensitive along the [001] direction (Z direction). We calculated the energy of intermolecular hydrogen bonds and the elastic constants of the TATB crystal using ab initio simulations, which also show anisotropy. We found that the unique structure of intermolecular hydrogen bonds and the difference in temperature rise induced by orientation-related compressibility are primarily responsible for the anisotropic shock wave sensitivity.

A relationship between membrane permeation and partitioning of nitroaromatic explosives and their functional groups. A computational study.

Nitroaromatic explosives, such as 2,4,6-trinitrotoluene, are representative aromatic compounds, which are generally highly toxic. For their toxic mechanisms, little is known about their interaction with cell membranes, although this is essential for their absorption, distribution, metabolism, excretion and toxicity profiling. Here, we investigated the membrane permeation and partitioning of 12 nitroaromatic explosives with typical functional groups (e.g., -NO2, -NH2, -OCH3 and -OH) by all-atom molecular dynamics simulations. Based on free-energy curves, we obtained three key parameters that describe the behavior of permeation and partitioning, namely liposome-water partition coefficient (KLW), permeability coefficient (P) and translocation time (τ). Functional groups contribute little to KLW, indicating that the membrane absorption of nitroaromatic explosives is primarily controlled by the hydrophobic effect of the benzene ring. P shows an obvious decline with increasing polar group number (Np), and therefore τ exhibits a continuous increase. In addition, the preferred location (zmin) of explosive molecules in membranes is closer to the head group of lipids when they have more polar groups. Further analysis shows that the hydrogen bond (H-bond) interaction of explosives with water and lipids plays a crucial role in the dependence of permeation and partitioning on polar groups. The molecules with larger Np can form more H-bonds with water in the aqueous phase, which limits their motion into the deeper hydrophobic region of membranes. Moreover, the desolvation/loss of H-bonds leave zmin controls the membrane permeation properties, which is also correlated with Np. The work reveals the physical essence of the relationship between the membrane permeation and partitioning of nitroaromatic explosives and their functional groups. These results may be also applicable to other (e.g., polycyclic) nitroaromatic compounds.

Effects of Low-level Lipid Peroxidation on the Permeability of Nitroaromatic Molecules across a Membrane: A Computational Study.

Lipid peroxidation (LPO) in cellular membranes can cause severe membrane damage and potential cell death. Although oxidized phospholipids have been proved to lead to great changes in the structures and properties of membranes, effects of low-level LPO on membrane permeability have not yet been fully understood. Here, we explored the molecular mechanism of low-level LPO changing the permeability of nitroaromatic molecules across a lipid bilayer by all-atom molecular dynamics simulations. The results reveal that the enhanced passive transport of nitroaromatic molecules lies in the size of defects (i.e., water "finger" and "cone"), which is further dependent on the extent of LPO and the structural feature of solutes. In detail, if the solute can form more hydrogen bonds with water, which stabilizes the water into a large-size cone, there is a greater permeability coefficient (P). Otherwise, a small-size finger only results in a small increase of P. For example, the presence of 15% oxidized lipids could result in an increase of 2,4,6-trinitrotoluene (TNT's) P by more than 2 orders of magnitude (from 1.7 × 10-2 to 2.39 cm·s-1). The result suggests that the membrane permeability can be greatly promoted in the physiologically relevant environment with low-level LPO, and more importantly, clarifies the contributions of both the hydrophobicity of the membrane interior and the structural feature of solutes to such enhanced permeability. This work may provide significant insight into the toxic effects of nitroaromatic molecules and the pharmaceutical characteristics of tissues with oxidative damage.

Comparison study of carbon clusters formation during thermal decomposition of 1,3,5-triamino-2,4,6-trinitrobenzene and benzotrifuroxan: a ReaxFF based sequential molecular dynamics simulation.

Carbon rich clusters are usually found after the detonation of explosives, which greatly hinder their further decomposition into small molecules. A comparison study of thermal decomposition and clusters formation between 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and benzotrifuroxan (BTF) crystals was conducted to uncover the mechanisms behind their distinct differences in sensitivity and reaction violence, which has not been investigated in detail. The simulations of heating at 3500 K, then expansion and cooling were conducted through reactive molecular dynamics using the ReaxFF-lg force field. As a result, the initial low decay rate indicates that TATB is more stable than BTF under high temperatures, while once ignited it decays faster than BTF. Nevertheless, BTF decomposes more completely with a higher potential energy release, a greater amount of final products, and higher reaction frequencies, and shows higher reaction violence than TATB. More and heavier clusters occur in TATB crystals compared with those in BTF. Large clusters form during the heating process and then partly dissociate during expansion and cooling. A faster cooling rate facilitates larger clusters formation. Graphitic geometries as well as carbon rings and carbon chains are common in the stable clusters. Besides, further simulations show that a lower heating temperature facilitates larger clusters formation both in TATB and BTF. Our results are expected to deepen the insight into the mechanisms of carbon clusters formation and the different performances of TATB and BTF.

Molecular Simulation Studies on the Interactions of 2,4,6-Trinitrotoluene and Its Metabolites with Lipid Membranes.

The penetration of chemicals into biological membranes is a key factor in the determination of their possible effects on organisms; this complex process involves mainly the interaction between chemicals and membranes. Here, we reported the interaction between a highly toxic class of explosives [2,4,6-trinitrotoluene (TNT) and its metabolites] and lipid membranes using molecular dynamics simulations. We calculated the permeability coefficient, transmembrane time, and liposome-water partition coefficient by integrating free-energy curves for all species. The results showed that TNT had a lower transmembrane capacity than its metabolites. Based on the liposome-water partition coefficient, we demonstrated that the membrane affinity of TNT is larger than that of its diamino metabolites but less than that of its monoamino metabolites. This result can qualitatively explain the difference of bioconcentration factors in experiments. The accumulation of TNT and metabolites in membranes can change the membrane structure, such as the area per lipid, the thickness of lipid bilayers, and the order of lipid tails and, further, the penetration of water. All of these are closely related to the interactions (mainly hydrogen bonds) of TNT and metabolites with lipid and water molecules. This work has a certain significance for understanding the toxicity of TNT and its metabolites.

Performance of cavitation flow and its induced noise of different jet pump cavitation reactors.

Jet pump is a type of cavitation reactor with great potential because of strong shear flow. In the present paper, experiments were carried out to investigate the cavitation characteristics of jet pump cavitation reactors (JPCRs) with different throat lengths, throat types and diffuser angles. Cavitation images and sound pressure signals in water corresponding to the hydraulic parameters are introduced to judge the aggressive intensity of cavitation in JPCRs. The flow ratios varying from the maximum limited value to -1 were measured for all JPCRs. It suggests that throat structure plays a more important role in the cavitation and flow characteristics of JPCR when compared with diffuser structure. Specifically, convergent throat results in large bubble density in the diffuser while divergent throat results in choke in the throat compared to the original JPCR. And cavitation bubble density in throat increases with increasing throat length. With the decrease of the flow ratio (q > 0), sound pressure level (SPL) decreases from the maximum to the minimum and then increases again. As the flow ratio decreases further (q < 0), SPL keeps on increasing first and then decreases, finally it takes a turn and increases to a stable level. Further study on actual SPL induced by cavitation in JPCR indicates that small diffuser angle, divergent and long throat enhance the aggressive intensity of cavitation. This result is of great significance to the design of JPCR.

Collective absorption of 2,4,6-trinitrotoluene into lipid membranes and its effects on bilayer properties. A computational study.

The widely used explosive, 2,4,6-trinitrotoluene (TNT), is a highly toxic chemical, which can cause hepatitis, cataracts, jaundice and so on, in humans. The interaction between TNT and biological membranes is crucial for understanding its toxic effects. Here, we mainly focused on molecular-level mechanisms for the collective adsorption of TNT into lipid membranes and the corresponding effects on bilayer properties by all-atom molecular dynamics simulations. We revealed that TNT can readily form an aggregate in the aqueous phase and quickly approach the surface of the membrane. At low concentrations of TNT (7 mol%), the aggregate is unstable and breaks up after several nanoseconds, and then the dispersed TNT molecules enter the membrane alone. At high concentrations (14 mol%), the aggregate is adsorbed as a whole and remains stable inside the membrane. After some of the TNT is absorbed by the membrane, the remaining TNT across the membrane would have greater permeability, i.e., the calculated permeability coefficient (P) is increased from 1.7 × 10-2 to 18.3 cm s-1. Correspondingly, a higher bioconcentration factor (BCF) was also observed. The increased level is more pronounced in the presence of TNT aggregates (i.e., high concentrations). This phenomenon is closely related to the strong interaction between TNT molecules. The results suggested that TNT molecules that have entered into the membrane can facilitate the membrane uptake, permeation and bioaccumulation of subsequent TNT molecules, exhibiting a synergistic effect. This work has a certain significance for understanding the toxicity of TNT.

The Safety Properties of a Potential Kind of Novel Green Primary Explosive: Al/Fe2O3/RDX Nanocomposite.

Green primary explosives have gained wide attention for environmental protection. A potential novel lead-free primary explosive, Al/Fe2O3/RDX hybrid nanocomposite was prepared by ultrasonic mixing, and its safety properties are discussed in detail. Results showed that their sensitivity and safety properties were a function of the specific surface area and proportions of their ingredients. Their impact sensitivity fell and their static discharge, flame, and hot bridge wire sensitivities rose as the specific surface area of nano-Fe2O3 increased. As the amount of Al/Fe2O3 nanothermite was increased, its impact sensitivity fell and its flame sensitivity rose; their static discharge and hot bridge wire sensitivities, however, followed an inverted "U" type change trend and were determined by both the particle size of the ingredients and the resistance of the nanocomposite. Their firing properties in an electric detonator depended on the proportion of the constituents. Thus, green nanoscale primary explosives are appropriate for a range of initiatory applications and can be created by adjusting their specific surface area and the amount of their constituents.

Self-assembly of single-wall carbon nanotubes during the cooling process of hot carbon gas.

In this work, self-assembly mechanism of single-wall carbon nanotube (SWCNT) during the annealing process of hot gaseous carbon is presented using reactive force field (ReaxFF)-based reactive molecular simulations. A series of simulations were performed on the evolution of reactive carbon gas. The simulation results show that the reactive carbon gas can be assembled into regular SWCNT without a catalyst. Five distinct stages of SWCNT self-assembly are proposed. For some initial configurations, the CNT was found to spin at an ultra-high rate after the nucleation. Graphical abstract Self-assembly process of single-wall carbon nanotube from the annealing of hot gaseous carbon.

Insight into electrostatic initiation of nitramine explosives.

The electrostatic safety of explosives is of great importance. However, the mechanism for the transfer of energy from an electrostatic spark to the reactive center of an explosive material is not well understood. Thus, in this work, we attempted to clarify the mechanism associated with the static-electricity-initiated detonation of explosives using a model of the interaction that incorporated relevant parameters. Nitramine explosives were considered as examples to study the relationship between electrostatic spark energy and 32 relevant parameters. The four parameters that were most closely correlated with the electrostatic spark energy were the standard deviation of the negative electrostatic potential, the minimum surface electrostatic potential, the minimum ionization energy, and the detonation pressure. A model for the dependence of the electrostatic spark energy on these four parameters was derived using the theoretical method known as genetic function approximation. The electrostatic spark energy values predicted using this model were in good agreement with the corresponding experimental values. The results of this work should lead to a deeper understanding of the electrostatic initiation mechanism of nitramines, and help to inspire the design of new explosives.

Influence of N-Oxide Introduction on the Stability of Nitrogen-Rich Heteroaromatic Rings: A Quantum Chemical Study.

N-Oxidization is an important strategy for enhancing the density and energy of energetic materials. Nevertheless, the influence of N+-O- introduction on molecular stability remains relatively unknown. Thus, the present work comprehensively studied 102 basic N-rich ring structures, including azoles, furazans, and azines, as well as their N-oxides by quantum chemical calculations. The introduction of N+-O- weakens molecular stability in most cases because the process elongates chemical bonds, decreases ring aromaticity, narrows the gaps between the highest occupied and lowest unoccupied molecular orbitals, and increases the photochemical reactivity. Besides, the easy H transfer to the neighboring O atom, which forms a N-OH isomer in azoles, renders the stabilization by N-oxide introduction ineffective. However, N-oxide introduction can enhance the molecular stability of 1,2,3,4-tetrazine-1,3-dioxide and tetrazino-tetrazine 1,3,6,8-tetraoxide by promoting σ-π separation and relieving lone-pair repulsion. Moreover, the alternate arrangement of positive and negative charges is another factor stabilizing the 1,2,3,4-tetrazine ring by 1,3-dioxidation. Finally, we assess the accessibility of N-oxidized azoles and azines by regarding N2O and H2O2 as oxidizers. We find that all the oxidations were exothermic, thermodynamically spontaneous, and kinetically feasible. After an overall evaluation, we propose 19 N-oxides as basic structures for high-energy materials with considerable stability.

Cluster Evolution at Early Stages of 1,3,5-Triamino-2,4,6-trinitrobenzene under Various Heating Conditions: A Molecular Reactive Force Field Study.

We carried out reactive molecular dynamics simulations by ReaxFF to study the initial events of an insensitive high explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) against various thermal stimuli including constant-temperature heating, programmed heating, and adiabatic heating to simulate TATB suffering from accidental heating in reality. Cluster evolution at the early stage of the thermal decomposition of condensed TATB was the main focus as cluster formation primarily occurs when TATB is heated. The results show that cluster formation is the balance of the competition of intermolecular collision and molecular decomposition of TATB, that is, an appropriate temperature and certain duration are required for cluster formation and preservation. The temperature in the range of 2000-3000 K was found to be optimum for fast formation and a period of preservation. Besides, the intra- and intermolecular H transfers are always favorable, whereas the C-NO2 partition was favorable at high temperature. The simulation results are helpful to deepen the insight into the thermal properties of condensed TATB.

Computational assessment of several hydrogen-free high energy compounds.

Tetrazino-tetrazine-tetraoxide (TTTO) is an attractive high energy compound, but unfortunately, it is not yet experimentally synthesized so far. Isomerization of TTTO leads to its five isomers, bond-separation energies were empolyed to compare the global stability of six compounds, it is found that isomer 1 has the highest bond-separation energy (1204.6kJ/mol), compared with TTTO (1151.2kJ/mol); thermodynamic properties of six compounds were theoretically calculated, including standard formation enthalpies (solid and gaseous), standard fusion enthalpies, standard vaporation enthalpies, standard sublimation enthalpies, lattice energies and normal melting points, normal boiling points; their detonation performances were also computed, including detonation heat (Q, cal/g), detonation velocity (D, km/s), detonation pressure (P, GPa) and impact sensitivity (h50, cm), compared with TTTO (Q=1311.01J/g, D=9.228km/s, P=40.556GPa, h50=12.7cm), isomer 5 exhibites better detonation performances (Q=1523.74J/g, D=9.389km/s, P=41.329GPa, h50= 28.4cm).

Experimental Investigation of Mechanical Properties of Black Shales after CO2-Water-Rock Interaction.

The effects of CO2-water-rock interactions on the mechanical properties of shale are essential for estimating the possibility of sequestrating CO2 in shale reservoirs. In this study, uniaxial compressive strength (UCS) tests together with an acoustic emission (AE) system and SEM and EDS analysis were performed to investigate the mechanical properties and microstructural changes of black shales with different saturation times (10 days, 20 days and 30 days) in water dissoluted with gaseous/super-critical CO2. According to the experimental results, the values of UCS, Young's modulus and brittleness index decrease gradually with increasing saturation time in water with gaseous/super-critical CO2. Compared to samples without saturation, 30-day saturation causes reductions of 56.43% in UCS and 54.21% in Young's modulus for gaseous saturated samples, and 66.05% in UCS and 56.32% in Young's modulus for super-critical saturated samples, respectively. The brittleness index also decreases drastically from 84.3% for samples without saturation to 50.9% for samples saturated in water with gaseous CO2, to 47.9% for samples saturated in water with super-critical carbon dioxide (SC-CO2). SC-CO2 causes a greater reduction of shale's mechanical properties. The crack propagation results obtained from the AE system show that longer saturation time produces higher peak cumulative AE energy. SEM images show that many pores occur when shale samples are saturated in water with gaseous/super-critical CO2. The EDS results show that CO2-water-rock interactions increase the percentages of C and Fe and decrease the percentages of Al and K on the surface of saturated samples when compared to samples without saturation.

Cluster evolution during the early stages of heating explosives and its relationship to sensitivity: a comparative study of TATB, ß-HMX and PETN by molecular reactive force field simulations.

Clustering is experimentally and theoretically verified during the complicated processes involved in heating high explosives, and has been thought to influence their detonation properties. However, a detailed description of the clustering that occurs has not been fully elucidated. We used molecular dynamic simulations with an improved reactive force field, ReaxFF_lg, to carry out a comparative study of cluster evolution during the early stages of heating for three representative explosives: 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), ß-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and pentaerythritol tetranitrate (PETN). These representatives vary greatly in their oxygen balance (OB), molecular structure, stability and experimental sensitivity. We found that when heated, TATB, HMX and PETN differ in the size, amount, proportion and lifetime of their clusters. We also found that the clustering tendency of explosives decreases as their OB becomes less negative. We propose that the relationship between OB and clustering can be attributed to the role of clustering in detonation. That is, clusters can form more readily in a high explosive with a more negative OB, which retard its energy release, secondary decomposition, further decomposition to final small molecule products and widen its detonation reaction zone. Moreover, we found that the carbon content of the clusters increases during clustering, in accordance with the observed soot, which is mainly composed of carbon as the final product of detonation or deflagration.