CIS is a potent checkpoint in NK cell-mediated tumor immunity.

The detection of aberrant cells by natural killer (NK) cells is controlled by the integration of signals from activating and inhibitory ligands and from cytokines such as IL-15. We identified cytokine-inducible SH2-containing protein (CIS, encoded by Cish) as a critical negative regulator of IL-15 signaling in NK cells. Cish was rapidly induced in response to IL-15, and deletion of Cish rendered NK cells hypersensitive to IL-15, as evidenced by enhanced proliferation, survival, IFN-γ production and cytotoxicity toward tumors. This was associated with increased JAK-STAT signaling in NK cells in which Cish was deleted. Correspondingly, CIS interacted with the tyrosine kinase JAK1, inhibiting its enzymatic activity and targeting JAK for proteasomal degradation. Cish(-/-) mice were resistant to melanoma, prostate and breast cancer metastasis in vivo, and this was intrinsic to NK cell activity. Our data uncover a potent intracellular checkpoint in NK cell-mediated tumor immunity and suggest possibilities for new cancer immunotherapies directed at blocking CIS function.

A chromosome-scale genome of Rhus chinensis Mill. provides new insights into plant-insect interaction and gallotannins biosynthesis.

Rhus chinensis Mill., an economically valuable Anacardiaceae species, is parasitized by the galling aphid Schlechtendalia chinensis, resulting in the formation of the Chinese gallnut (CG). Here, we report a chromosomal-level genome assembly of R. chinensis, with a total size of 389.40 Mb and scaffold N50 of 23.02 Mb. Comparative genomic and transcriptome analysis revealed that the enhanced structure of CG and nutritional metabolism contribute to improving the adaptability of R. chinensis to S. chinensis by supporting CG and galling aphid growth. CG was observed to be abundant in hydrolysable tannins (HT), particularly gallotannin and its isomers. Tandem repeat clusters of dehydroquinate dehydratase/shikimate dehydrogenase (DQD/SDH) and serine carboxypeptidase-like (SCPL) and their homologs involved in HT production were determined as specific to HT-rich species. The functional differentiation of DQD/SDH tandem duplicate genes and the significant contraction in the phenylalanine ammonia-lyase (PAL) gene family contributed to the accumulation of gallic acid and HT while minimizing the production of shikimic acid, flavonoids, and condensed tannins in CG. Furthermore, we identified one UDP glucosyltransferase (UGT84A), three carboxylesterase (CXE), and six SCPL genes from conserved tandem repeat clusters that are involved in gallotannin biosynthesis and hydrolysis in CG. We then constructed a regulatory network of these genes based on co-expression and transcription factor motif analysis. Our findings provide a genomic resource for the exploration of the underlying mechanisms of plant-galling insect interaction and highlight the importance of the functional divergence of tandem duplicate genes in the accumulation of secondary metabolites.

The Helix-Loop-Helix Protein ID2 Governs NK Cell Fate by Tuning Their Sensitivity to Interleukin-15.

The inhibitor of DNA binding 2 (Id2) is essential for natural killer (NK) cell development with its canonical role being to antagonize E-protein function and alternate lineage fate. Here we have identified a key role for Id2 in regulating interleukin-15 (IL-15) receptor signaling and homeostasis of NK cells by repressing multiple E-protein target genes including Socs3. Id2 deletion in mature NK cells was incompatible with their homeostasis due to impaired IL-15 receptor signaling and metabolic function and this could be rescued by strong IL-15 receptor stimulation or genetic ablation of Socs3. During NK cell maturation, we observed an inverse correlation between E-protein target genes and Id2. These results shift the current paradigm on the role of ID2, indicating that it is required not only to antagonize E-proteins during NK cell commitment, but constantly required to titrate E-protein activity to regulate NK cell fitness and responsiveness to IL-15.

Neurophysiological features of STN LFP underlying sleep fragmentation in Parkinson's disease.

BACKGROUND: Sleep fragmentation is a persistent problem throughout the course of Parkinson's disease (PD). However, the related neurophysiological patterns and the underlying mechanisms remained unclear. METHOD: We recorded subthalamic nucleus (STN) local field potentials (LFPs) using deep brain stimulation (DBS) with real-time wireless recording capacity from 13 patients with PD undergoing a one-night polysomnography recording, 1 month after DBS surgery before initial programming and when the patients were off-medication. The STN LFP features that characterised different sleep stages, correlated with arousal and sleep fragmentation index, and preceded stage transitions during N2 and REM sleep were analysed. RESULTS: Both beta and low gamma oscillations in non-rapid eye movement (NREM) sleep increased with the severity of sleep disturbance (arousal index (ArI)-betaNREM: r=0.9, p=0.0001, sleep fragmentation index (SFI)-betaNREM: r=0.6, p=0.0301; SFI-gammaNREM: r=0.6, p=0.0324). We next examined the low-to-high power ratio (LHPR), which was the power ratio of theta oscillations to beta and low gamma oscillations, and found it to be an indicator of sleep fragmentation (ArI-LHPRNREM: r=-0.8, p=0.0053; ArI-LHPRREM: r=-0.6, p=0.0373; SFI-LHPRNREM: r=-0.7, p=0.0204; SFI-LHPRREM: r=-0.6, p=0.0428). In addition, long beta bursts (>0.25 s) during NREM stage 2 were found preceding the completion of transition to stages with more cortical activities (towards Wake/N1/REM compared with towards N3 (p<0.01)) and negatively correlated with STN spindles, which were detected in STN LFPs with peak frequency distinguishable from long beta bursts (STN spindle: 11.5 Hz, STN long beta bursts: 23.8 Hz), in occupation during NREM sleep (ß=-0.24, p<0.001). CONCLUSION: Features of STN LFPs help explain neurophysiological mechanisms underlying sleep fragmentations in PD, which can inform new intervention for sleep dysfunction. TRIAL REGISTRATION NUMBER: NCT02937727.

Contribution of basal ganglia activity to REM sleep disorder in Parkinson's disease.

BACKGROUND: Rapid eye movement (REM) sleep behaviour disorder (RBD) is one of the most common sleep problems and represents a key prodromal marker in Parkinson's disease (PD). It remains unclear whether and how basal ganglia nuclei, structures that are directly involved in the pathology of PD, are implicated in the occurrence of RBD. METHOD: Here, in parallel with whole-night video polysomnography, we recorded local field potentials from two major basal ganglia structures, the globus pallidus internus and subthalamic nucleus, in two cohorts of patients with PD who had varied severity of RBD. Basal ganglia oscillatory patterns during RBD and REM sleep without atonia were analysed and compared with another age-matched cohort of patients with dystonia that served as controls. RESULTS: We found that beta power in both basal ganglia nuclei was specifically elevated during REM sleep without atonia in patients with PD, but not in dystonia. Basal ganglia beta power during REM sleep positively correlated with the extent of atonia loss, with beta elevation preceding the activation of chin electromyogram activities by ~200 ms. The connectivity between basal ganglia beta power and chin muscular activities during REM sleep was significantly correlated with the clinical severity of RBD in PD. CONCLUSIONS: These findings support that basal ganglia activities are associated with if not directly contribute to the occurrence of RBD in PD. Our study expands the understanding of the role basal ganglia played in RBD and may foster improved therapies for RBD by interrupting the basal ganglia-muscular communication during REM sleep in PD.

Development of an online calculator for the prediction of seizure freedom following pediatric hemispherectomy using the Hemispherectomy Outcome Prediction Scale (HOPS).

OBJECTIVES: Although hemispheric surgeries are among the most effective procedures for drug-resistant epilepsy (DRE) in the pediatric population, there is a large variability in seizure outcomes at the group level. A recently developed HOPS score provides individualized estimation of likelihood of seizure freedom to complement clinical judgement. The objective of this study was to develop a freely accessible online calculator that accurately predicts the probability of seizure freedom for any patient at 1-, 2-, and 5-years post-hemispherectomy. METHODS: Retrospective data of all pediatric patients with DRE and seizure outcome data from the original Hemispherectomy Outcome Prediction Scale (HOPS) study were included. The primary outcome of interest was time-to-seizure recurrence. A multivariate Cox proportional-hazards regression model was developed to predict the likelihood of post-hemispheric surgery seizure freedom at three time points (1-, 2- and 5- years) based on a combination of variables identified by clinical judgment and inferential statistics predictive of the primary outcome. The final model from this study was encoded in a publicly accessible online calculator on the International Network for Epilepsy Surgery and Treatment (iNEST) website (https://hops-calculator.com/). RESULTS: The selected variables for inclusion in the final model included the five original HOPS variables (age at seizure onset, etiologic substrate, seizure semiology, prior non-hemispheric resective surgery, and contralateral fluorodeoxyglucose-positron emission tomography [FDG-PET] hypometabolism) and three additional variables (age at surgery, history of infantile spasms, and magnetic resonance imaging [MRI] lesion). Predictors of shorter time-to-seizure recurrence included younger age at seizure onset, prior resective surgery, generalized seizure semiology, FDG-PET hypometabolism contralateral to the side of surgery, contralateral MRI lesion, non-lesional MRI, non-stroke etiologies, and a history of infantile spasms. The area under the curve (AUC) of the final model was 73.0%. SIGNIFICANCE: Online calculators are useful, cost-free tools that can assist physicians in risk estimation and inform joint decision-making processes with patients and families, potentially leading to greater satisfaction. Although the HOPS data was validated in the original analysis, the authors encourage external validation of this new calculator.

Synthesis and Study of Steering of Azido-tetrazole Behavior in Tetrazolo[1,5-c]pyrimidin-5-amine-Based Energetic Materials.

Tetrazoles and their derivatives are essential for compound synthesis due to their versatility, effectiveness, stability in air, and cost-efficiency. This has stimulated interest in developing techniques for their production. In this work, four compounds, tetrazolo[1,5-c]pyrimidin-5-amine (1), N-(4-azidopyrimidin-2-yl)nitramide (2), tetrazolo[1,5-c]pyrimidin-5(6H)-one (3), and tetrazolo[1,5-a]pyrimidin-5-amine (4), were obtained from commercially available reagents and straightforward synthetic methodologies. These new compounds were characterized by infrared (IR), 13C, and 1H NMR spectroscopy, differential scanning calorimetry (DSC), and single-crystal X-ray diffraction. The solvent, temperature, and electron-donating group (EDG) factors that were responsible for the steering of azido-tetrazole equilibrium in all compounds were also studied. In addition, the detonation performance of the target compounds was calculated by using heats of formation (HOFs) and crystal densities. Hirshfeld surface analysis was used to examine the intermolecular interactions of the four synthesized compounds. The results show that the excellent properties of 1-4 are triggered by ionic bonds, hydrogen bonds, and π-π stacking interactions, indicating that these compounds have the potential to be used in the development of high-performance energetic materials. Additionally, DFT analysis is in support of experimental results, which proved the effect of different factors that can influence the azido-tetrazole equilibrium in the synthesized pyrimidine derivatives in the solution.

Multimodal mapping of regional brain vulnerability to focal cortical dysplasia.

Focal cortical dysplasia (FCD) type II is a highly epileptogenic developmental malformation and a common cause of surgically treated drug-resistant epilepsy. While clinical observations suggest frequent occurrence in the frontal lobe, mechanisms for such propensity remain unexplored. Here, we hypothesized that cortex-wide spatial associations of FCD distribution with cortical cytoarchitecture, gene expression and organizational axes may offer complementary insights into processes that predispose given cortical regions to harbour FCD. We mapped the cortex-wide MRI distribution of FCDs in 337 patients collected from 13 sites worldwide. We then determined its associations with (i) cytoarchitectural features using histological atlases by Von Economo and Koskinas and BigBrain; (ii) whole-brain gene expression and spatiotemporal dynamics from prenatal to adulthood stages using the Allen Human Brain Atlas and PsychENCODE BrainSpan; and (iii) macroscale developmental axes of cortical organization. FCD lesions were preferentially located in the prefrontal and fronto-limbic cortices typified by low neuron density, large soma and thick grey matter. Transcriptomic associations with FCD distribution uncovered a prenatal component related to neuroglial proliferation and differentiation, likely accounting for the dysplastic makeup, and a postnatal component related to synaptogenesis and circuit organization, possibly contributing to circuit-level hyperexcitability. FCD distribution showed a strong association with the anterior region of the antero-posterior axis derived from heritability analysis of interregional structural covariance of cortical thickness, but not with structural and functional hierarchical axes. Reliability of all results was confirmed through resampling techniques. Multimodal associations with cytoarchitecture, gene expression and axes of cortical organization indicate that prenatal neurogenesis and postnatal synaptogenesis may be key points of developmental vulnerability of the frontal lobe to FCD. Concordant with a causal role of atypical neuroglial proliferation and growth, our results indicate that FCD-vulnerable cortices display properties indicative of earlier termination of neurogenesis and initiation of cell growth. They also suggest a potential contribution of aberrant postnatal synaptogenesis and circuit development to FCD epileptogenicity.

Astrocyte-derived SerpinA3N promotes neuroinflammation and epileptic seizures by activating the NF-κB signaling pathway in mice with temporal lobe epilepsy.

Impaired activation and regulation of the extinction of inflammatory cells and molecules in injured neuronal tissues are key factors in the development of epilepsy. SerpinA3N is mainly associated with the acute phase response and inflammatory response. In our current study, transcriptomics analysis, proteomics analysis, and Western blotting showed that the expression level of Serpin clade A member 3N (SerpinA3N) is significantly increased in the hippocampus of mice with kainic acid (KA)-induced temporal lobe epilepsy, and this molecule is mainly expressed in astrocytes. Notably, in vivo studies using gain- and loss-of-function approaches revealed that SerpinA3N in astrocytes promoted the release of proinflammatory factors and aggravated seizures. Mechanistically, RNA sequencing and Western blotting showed that SerpinA3N promoted KA-induced neuroinflammation by activating the NF-κB signaling pathway. In addition, co-immunoprecipitation revealed that SerpinA3N interacts with ryanodine receptor type 2 (RYR2) and promotes RYR2 phosphorylation. Overall, our study reveals a novel SerpinA3N-mediated mechanism in seizure-induced neuroinflammation and provides a new target for developing neuroinflammation-based strategies to reduce seizure-induced brain injury.

Monitoring the Micro-Structural Evolution Mechanism of Next-Generation Ultra-High-Energy All-Nitrogen Materials: A Molecular Dynamic Study.

Micro-structural evolution mechanisms of next-generation ultra-high-energy all-nitrogen materials under the extreme conditions of high temperature coupled with high pressure were revealed by state-of-the-art ab initio molecular dynamics studies based on highest-nitrogen-content energetic material 2,2'-azobis(5-azidotetrazole). The results indicate that there are three primary initial uni-molecular decomposition pathways, namely, tetrazole ring opening, azido group elimination, and the breaking of the N-N bond between the azo group and azidotetrazole. In complicated global decomposition reactions, there exists the formation of nitrogen-rich clusters and all-nitrogen species. Lowering the temperature or increasing the pressure is conducive to increasing the N content in the nitrogen-rich cluster and widening the time distribution for the cluster. Abundant all-nitrogen species N4, N5, N6, N7, N8, N9, N10, and N13 were formed, and their detailed evolutionary process and construction mechanisms were enunciated. We innovatively constructed a series of next-generation ultra-high-energy all-nitrogen materials, which are expected to realize the controllable construction of next-generation ultra-high-energy all-nitrogen materials under extreme conditions.

Preparation of High-Energy ECPs by Retaining the Coordination Ability of Carbohydrazide Groups.

In order to preserve the coordinating ability of the hydrazide group, we used retrosynthetic analysis to design and synthesize ligand furan-2,5-dicarbohydrazide and its complex [Cu(FDCA)(H2O)ClO4]n(ClO4)n·nH2O (ECPs-1·H2O). The structure of the product was confirmed by single-crystal X-ray diffraction, infrared spectroscopy, and elemental analysis. The solvent-free target material ECPs-1 exhibited good thermal stability, sensitivity to mechanical stimuli, and excellent explosive properties. Furthermore, it had good potential for laser ignition and comparable detonation power to LA. The simple preparation method and inexpensive starting materials enriched the research on primary explosives.

Evolutionary research trend of Polygonatum species: a comprehensive account of their transformation from traditional medicines to functional foods.

With the advances in Polygonatum research, there is a huge interest in harnessing the valuable functional ingredients of this genus with the potential for functional foods. This review emphasizes the different aspects of Ploygonatum based research starting from its bioactive compounds, their structural characterization, various extraction methods, as well as biological activities. In view of its integral use as an essential medicinal plant, our review emphasizes on its promising food applications both as an ingredient and as a whole food, and its improved health benefits with potential for agricultural and environmental relevance are also discussed. As we collated the recent research information, we present the main challenges and limitations of the current research trend in this area which can upgrade the further expansion of Polygonatum-related research that will strengthen its economic and accessible nutritional value in the food and health industries. By highlighting the need for the unattended species, this review not only fills existing research gaps, but also encourages the researchers to find new avenues for the natural production of bio-based functional materials and the development of highly functional and health-promoting foods for disease prevention and treatment.

Lycium barbarum (Goji) as functional food: a review of its nutrition, phytochemical structure, biological features, and food industry prospects.

Lycium genus (Goji berry) is recognized as a good source of homology of medicine and food, with various nutrients and phytochemicals. Lately, numerous studies have focused on the chemical constituents and biological functions of the L. barbarum L., covering phytochemical and pharmacological aspects. We aim to provide exclusive data on the nutrients of L. barbarum L. fruits and phytochemicals, including their structural characterization, the evolution of extraction, and purification processes of different phytochemicals of L. barbarum L. fruit while placing greater emphasis on their wide-ranging health effects. This review also profitably offers innovative approaches for the food industry and industrial applications of L. barbarum L. and addresses some current situations and problems in the development of L. barbarum L. in deep processing products, which can provide clues for the sustainable development of L. barbarum L. industry.

Long-term result of 125 I seed brachytherapy for pediatric desmoid tumor in the head and neck.

BACKGROUND: Desmoid tumor (DT) is rare and challenging, often affects the head and neck (HN) region in children, and its appropriate treatments are under-discussed. This study aimed to retrospectively evaluate the long-term effectiveness and safety of 125 I seed brachytherapy for pediatric DT in HN. PROCEDURE: Seven pediatric patients with a median age of three years who suffered from DT in HN treated with 125 I brachytherapy from January 2008 to June 2018 were included. Among these, five underwent sole brachytherapy and the others combined with surgery under prescription doses ranging from 10,000 to 12,000 cGy. The rate of local control (LC), complete response (CR), and partial response (PR) was calculated after evaluation by radiological and pathological means. Radiation-associated toxicities were also evaluated. RESULTS: The LC rate was 7/7 during the follow-up time ranging from 43 to 135 months and with a mean of 57 months. No recurrent lesion was found in the patients receiving surgery combined with brachytherapy. In patients treated with sole brachytherapy, the radiological PR rate and CR rate were 4/5 and 1/5, respectively. In those reaching radiological PR, 3/4 were pathological CR. Slight acute radiation-associated toxicities were observed in all patients, and no late or severe acute toxicity was observed. CONCLUSION: 125 I brachytherapy is effective and safe in the management of pediatric DT in HN as the sole modality or combined with surgery in the long term.

Preparation of Primary Explosive by Self-assembly of Combustible and Oxidizing Agents under Acid.

In order to further explore the effect of ligands on the performance of primary explosives and gain a deeper understanding of the coordination mechanism, we designed furan-2-carbohydrazide (FRCA), a ligand, by using oxygen-containing heterocycles and carbohydrazide. Then, FRCA and Cu(ClO4)2 were used to synthesize coordination compounds [Cu(FRCA)2(H2O)(ClO4)2]·CH3OH (ECCs-1·CH3OH) and Cu(FRCA)2(H2O)(ClO4)2 (ECCs-1). The structure of the ECCs-1 was confirmed by single-crystal X-ray diffraction, IR and EA characterization. Further experiments on ECCs-1 show that ECCs-1 has good thermal stability, but is sensitive to mechanical stimuli (impact sensitivity = IS = 8 J, friction sensitivity = FS = 20 N). The predicted value of the detonation parameter is DEXPLO 5 = 6.6 km s-1, PEXPLO 5 = 18.8 GPa, but the ignition test, laser test, and lead plate detonation experiment show that ECCs-1 has excellent detonation performance, which is very worthy of attention.

Metal Salts of 4-Chloro-3,5-dinitropyrazole for Promising Eco-Friendly Primary Colors Pyrotechnics.

The construction and design of pyrotechnics with superior performance is not only a task of great significance but also a tremendous challenge. In this regard, we present the syntheses of novel green primary colors pyrotechnics (red, green, and blue light-generating pyrotechnics) by employing 4-chloro-3,5-dinitropyrazole (CDNP) as a multifunctional raw material. CDNP contains a flame enhancer, oxygen-rich functional group, and nitrogen heterocyclic combustibles, which contribute to the high performance of the pyrotechnics. The characteristic elements (strontium, barium, and copper) that impart color to the flame are combined with the CDNP to synthesize the primary colors pyrotechnics by an "all-in-one" strategy. The structures of three energetic metal salts (EMS-1, EMS-2, and EMS-3) are completely characterized, and their thermal stability, sensitivity, ignition performance, and color purity are systematically evaluated. All EMSs show excellent thermal stability and low mechanical sensitivities (>330 °C, >40 J, >360 N). Moreover, the EMSs demonstrate successful ignition and combustion under laser conditions and roasting test conditions, producing bright characteristic flames. Chromaticity analysis reveals that the three EMSs possess good color purities of 91, 80, and 70%, respectively. Consequently, the three integrated pyrotechnics exhibit exceptional combustion properties, highlighting their potential for use in various pyrotechnic applications.

Preparation of Highly Energetic Coordination Compounds with Rich Oxidants and Lower Sensitivity Based on Methyl Groups.

Revamping the structure of energy storage is an efficient strategy for striking a balance between the performance and sensitivity of energetic materials to achieve high energy and reduced sensitivity. In continuation of prior research, this study utilized the ligand 3,5-dimethyl-1H-pyrazole-4-carbonhydrazide (DMPZCA) and innovatively designed and synthesized the compound ECCs [Cu(HDMPZCA)2(ClO4)2](ClO4)2·2H2O (ECCs-1·2H2O). Compared with the former research, solvent-free compound ECCs-1 refers to an innovative material characterized by a dual structure involving ionic salts and coordination compounds. Due to these unique structures, ECCs-1 exhibits an increased [ClO4-] content, a higher oxygen balance constant (OB = -7.9%), and improved mechanical sensitivity (IS = 8 J, FS = 32 N). Theoretical calculations support the superior detonation performance of ECCs-1. Additionally, experimental results confirm its ignition capability through lower-threshold lasers and highlight the outstanding initiation potential and explosive power, making it a suitable candidate for primary explosives.

Elucidating the Motif for CpG Oligonucleotide Binding to the Dendritic Cell Receptor DEC-205 Leads to Improved Adjuvants for Liver-Resident Memory.

DEC-205 is a cell-surface receptor that transports bound ligands into the endocytic pathway for degradation or release within lysosomal endosomes. This receptor has been reported to bind a number of ligands, including keratin, and some classes of CpG oligodeoxynucleotides (ODN). In this study, we explore in detail the requirements for binding ODNs, revealing that DEC-205 efficiently binds single-stranded, phosphorothioated ODN of ≥14 bases, with preference for the DNA base thymidine, but with no requirement for a CpG motif. DEC-205 fails to bind double-stranded phosphodiester ODN, and thus does not bind the natural type of DNA found in mammals. The ODN binding preferences of DEC-205 result in strong binding of B class ODN, moderate binding to C class ODN, minimal binding to P class ODN, and no binding to A class ODN. Consistent with DEC-205 binding capacity, induction of serum IL-12p70 or activation of B cells by each class of ODN correlated with DEC-205 dependence in mice. Thus, the greater the DEC-205 binding capacity, the greater the dependence on DEC-205 for optimal responses. Finally, by covalently linking a B class ODN that efficiently binds DEC-205, to a P class ODN that shows poor binding, we improved DEC-205 binding and increased adjuvancy of the hybrid ODN. The hybrid ODN efficiently enhanced induction of effector CD8 T cells in a DEC-205-dependent manner. Furthermore, the hybrid ODN induced robust memory responses, and was particularly effective at promoting the development of liver tissue-resident memory T cells.

Phase transition-induced initial decomposition of nitrogen-rich binary CN compound 2,2'-azobis(5-azidotetrazole) and its precursor 2-amino-5-azidotetrazole via tetrazole ring opening under external electric fields: a comparative DFT-D study.

A comparative DFT-D study was performed to investigate the external electric field-induced crystal structures, electronic features, Hirshfeld surfaces, vibrational properties and initial decomposition mechanisms of nitrogen-rich binary CN compound 2,2'-azobis(5-azidotetrazole) (C2N16) and its precursor 2-amino-5-azidotetrazole (CH2N8). The results show that there exist phase transitions at the critical points of 0.006 a.u. and 0.008 a.u. for CH2N8 and C2N16, respectively, which are embodied in various properties of these compounds and induce their initial decomposition of the tetrazole ring opening via the breaking of N-N single bonds. The analysis of band gaps and density of states suggests the external electric field-induced enhancing ability for electron transition from the occupied orbitals to empty ones and N-N bond breaking may be the initial decomposition pathway for them. The variations in Hirshfeld surfaces indicate the spatial change and adjustment of non-bonding interactions in the two crystals. The discussions on vibrational properties indicate that IR characteristic peaks of all vibrational modes in the two crystals show a gradual red shift toward a low frequency region. The external electric field-induced initial decomposition pathways of both crystals are tetrazole ring opening via the breaking of a N-N single bond. Our findings provide insights for a comprehensive understanding of external electric field-induced phase transition and initial decomposition mechanisms of nitrogen-rich binary CN energetic compounds.