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.

Optimization of performance and sensitivity: preparation of two Ag(I)-based ECPs by using isomeric ligands

For energetic compounds, their structure determines their performance, and even minor variations in their structure can have a significant impact on their performance. The application scenarios for energetic materials are diverse, and their performance requirements vary as well. To investigate the influence of different substituent positions on the performance of primary explosives, we prepared two Ag(I)-based complexes, [Ag(2-IZCA)ClO4]n (ECPs-1) and [Ag(4-IZCA)ClO4]n (ECPs-2), using structurally isomeric ligands, 1H-imidazole-2-carbohydrazide (2-IZCA) and 1H-imidazole-4-carbohydrazide (4-IZCA). The structures were confirmed using infrared, elemental analysis, and single-crystal X-ray diffraction. Experimental results demonstrate that both ECPs exhibit good thermal stability. However, compared to ECPs-1, ECPs-2 exhibits a lower thermal initial decomposition temperature (Td = 210 °C), lower mechanical sensitivity (IS = 27 J, FS = 84 N), and more concentrated energy output. Although theoretical predictions suggest similar detonation velocities and pressures for both compounds, actual detonation performance tests indicate that ECPs-2 has stronger explosive power and initiating capability, with potential for use as a laser initiator (E = 126 mJ). The simple preparation method and inexpensive starting materials enrich the research on primary explosives.

Structural, vibrational and electronic properties of nitrogen-rich 2,4,6-triazide-1,3,5-triazine under high pressure

CONTEXT AND RESULTS

2,4,6-triazide-1,3,5-triazine (TAT) has received widespread attention for its great potential to synthesize or convert to nitrogen-rich high energy density materials (HEDMs). The TAT structure alteration in the compression process up to 30 GPa has characteristics as follows: (a) [N₃] groups straighten; (b) [N₃] groups gather toward the six-membered C-N heterocycles. At about 5 GPa, Raman peak split at 700 cm^-1 was observed both in calculation and in-situ Raman experiment, which is caused by pressure-induced intramolecular stress. Besides, the broad band of the amorphous two-dimensional C=N network (centered at 1630 cm^-1) occurred at about 12 GPa. Meantime, the study on electronic features suggests the pressure-induced deformation in TAT molecular structure cause the discontinuous change of band gap at about 4.5 GPa and 8.0 GPa, respectively.

COMPUTATIONAL AND THEORETICAL TECHNIQUES

The static compression process of TAT was explored in the range of 0-30 GPa by using dispersion corrected density functional theory (DFT-D) calculations combined with in-situ Raman experiment. The GGA/PBE+G06 method that has less errors than other calculation methods was used to predict the geometry structure, vibrational properties and electronic structure of TAT under pressure.

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.

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 D_EXPLO 5 = 6.6 km s^-1, P_EXPLO 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.

Extraordinary high ductility/strength of the interface designed bulk W-ZrC alloy plate at relatively low temperature

The refractory tungsten alloys with high ductility/strength/plasticity are highly desirable for a wide range of critical applications. Here we report an interface design strategy that achieves 8.5 mm thick W-0.5 wt. %ZrC alloy plates with a flexural strength of 2.5 GPa and a strain of 3% at room temperature (RT) and ductile-to-brittle transition temperature of about 100 °C. The tensile strength is about 991 MPa at RT and 582 MPa at 500 °C, as well as total elongation is about 1.1% at RT and as large as 41% at 500 °C, respectively. In addition, the W-ZrC alloy plate can sustain 3.3 MJ/m² thermal load without any cracks. This processing route offers the special coherent interfaces of grain/phase boundaries (GB/PBs) and the diminishing O impurity at GBs, which significantly strengthens GB/PBs and thereby enhances the ductility/strength/plasticity of W alloy. The design thought can be used in the future to prepare new alloys with higher ductility/strength.

Construction of a genome-scale metabolic network of the plant pathogen Pectobacterium carotovorum provides new strategies for bactericide discovery

We reconstructed the first genome-scale metabolic network of the plant pathogen Pectobacterium carotovorum subsp. carotovorum PC1 based on its genomic sequence, annotation, and physiological data. Metabolic characteristics were analyzed using flux balance analysis (FBA), and the results were afterwards validated by phenotype microarray (PM) experiments. The reconstructed genome-scale metabolic model, iPC1209, contains 2235 reactions, 1113 metabolites and 1209 genes. We identified 19 potential bactericide targets through a comprehensive in silico gene-deletion study. Next, we performed virtual screening to identify candidate inhibitors for an important potential drug target, alkaline phosphatase, and experimentally verified that three lead compounds were able to inhibit both bacterial cell viability and the activity of alkaline phosphatase in vitro. This study illustrates a new strategy for the discovery of agricultural bactericides.

Cytokine-induced killer cells in the treatment of patients with solid carcinomas: a systematic review and pooled analysis

BACKGROUND AIMS

The aim of this study was to evaluate the efficacy and safety of cytokine-induced killer (CIK) cell therapy for solid carcinomas.

METHODS

We performed a computerized search of phase II/III clinical trial databases of CIK cell-based therapy using a combination of the terms 'cytokine-induced killer cells', 'tumor' and 'cancer'.

RESULTS

Treatment with CIK cells was associated with a significantly improved half-year survival (P = 0.003), 1-year survival (P = 0.0005), 2-year survival (P < 0.01) and mean survival time (MST) (P < 0.001). Patients in the CIK group showed a prolonged half-year progression-free survival (PFS) (P < 0.01), 1-year PFS (P < 0.01) and median time to progression (MTTP) (P < 0.001). A favored disease control rate (DCR) was observed in patients receiving CIK cell therapy, while the objective response rate (ORR) was not altered (P = 0.05) compared with the non-CIK group (P = 0.007). CIK cell therapy could also reduce the adverse effects of grade III and IV leukopenia caused by chemotherapy (P = 0.002) and diminish hepatitis B virus (HBV)-DNA content (P < 0.01). However, the incidence of fever in the CIK therapy group was significantly higher than in the non-CIK group (P = 0.02). The percentage of CD3(+), CD4(+), CD4(+)CD8(+), CD3(-) CD56(+) and CD3(+) CD56(+) T-lymphocyte subsets in the peripheral blood of cancer patients was significantly increased, whereas the percentage of CD8(+) T-lymphocyte cells was significantly decreased in the CIK group compared with the non-CIK group (P < 0.01).

CONCLUSIONS

CIK cell therapy has demonstrated a significant superiority in prolonging the MST, PFS, DCR and quality of life (QoL) of patients.

Cytokine-induced killer cells in the treatment of patients with solid carcinomas: a systematic review and pooled analysis

BACKGROUND AIMS

The aim of this study was to evaluate the efficacy and safety of cytokine-induced killer (CIK) cell therapy for solid carcinomas.

METHODS

We performed a computerized search of phase II/III clinical trial databases of CIK cell-based therapy using a combination of the terms 'cytokine-induced killer cells', 'tumor' and 'cancer'.

RESULTS

Treatment with CIK cells was associated with a significantly improved half-year survival (P = 0.003), 1-year survival (P = 0.0005), 2-year survival (P < 0.01) and mean survival time (MST) (P < 0.001). Patients in the CIK group showed a prolonged half-year progression-free survival (PFS) (P < 0.01), 1-year PFS (P < 0.01) and median time to progression (MTTP) (P < 0.001). A favored disease control rate (DCR) was observed in patients receiving CIK cell therapy, while the objective response rate (ORR) was not altered (P = 0.05) compared with the non-CIK group (P = 0.007). CIK cell therapy could also reduce the adverse effects of grade III and IV leukopenia caused by chemotherapy (P = 0.002) and diminish hepatitis B virus (HBV)-DNA content (P < 0.01). However, the incidence of fever in the CIK therapy group was significantly higher than in the non-CIK group (P = 0.02). The percentage of CD3(+), CD4(+), CD4(+)CD8(+), CD3(-) CD56(+) and CD3(+) CD56(+) T-lymphocyte subsets in the peripheral blood of cancer patients was significantly increased, whereas the percentage of CD8(+) T-lymphocyte cells was significantly decreased in the CIK group compared with the non-CIK group (P < 0.01).

CONCLUSIONS

CIK cell therapy has demonstrated a significant superiority in prolonging the MST, PFS, DCR and quality of life (QoL) of patients.

Risk assessment for safety of soils and vegetables around a lead/zinc mine

Concentrations of heavy metals (Pb, Zn, Cd, Cu) were determined in soils and vegetables (chrysanthemum, spinach and four cultivars of Chinese cabbage from the area adjacent to a Pb/Zn mine in Shaoxing, Zhejiang province, China, and compared with the Chinese National Standards for Soil Environmental Quality. The accumulation of heavy metals in cabbage cv. Siyuegreen was investigated at different distances from the center of the mine. The vegetable plantation soils were polluted with Pb, Cd, Cu and Zn, especially by Pb and Cd. The levels of Pb and Cd were 20 and 30 times higher than the permitted standards, indicating that this Pb/Zn mining area is unsuitable for agricultural use. Chinese cabbage, chrysanthemum and spinach had different enrichment coefficients. The enrichment coefficient of Cd from soil to roots of chrysanthemum was >80% and from roots to leaves of cabbage cv. Shanghaigreen was >120%. These vegetables were polluted by heavy metals and could not be regarded as safe for human consumption. Environmental accumulation of heavy metals in the vegetable plantation soils was proportional to heavy metal accumulation in vegetables and both were inversely proportional to the distance from the lead/zinc mine.

Nitrogen removal from the saline sludge liquor by electrochemical denitrification

Sludge liquor from the sludge dewatering process has a high ammonia content. In the present study, a lab-scale electrochemical (EC) system with a pair of Ti electrode plates was used for treating the sludge centrate liquor of digested wastewater sludge with a NH4(+) - N content of around 500 mg/L. The sludge liquor had a high salinity due to seawater being used for toilet flushing in Hong Kong. The results show that the EC process is highly effective for denitrification of the saline sludge liquor. Complete nitrogen removal could be achieved within 1 hr or so. The rate of EC denitrification increased with the current intensity applied. The best current efficiency for nitrogen removal was obtained for a gap distance between the electrodes at 8 mm. Electro-chlorination was considered to be the major mechanism of EC denitrification. The formation of chlorination by-products (CBPs) appeared to be minimal with the total trihalomethanes (THM) detected at a level of 300 microg/L or lower. The power consumption for EC denitrification was around 23 kWh/kg N. Additional electro-flocculation with a pair of iron needle electrodes could enhance the flocculation and subsequent sedimentation of colloidal organics in the sludge liquor, increasing the organic removal from less than 30% to more than 70%. Therefore, the EC process including both electro-denitrification and electro-flocculation can be developed as the most cost-effective method for treatment of the saline sludge liquor.

Study on fluoride emission from soils at high temperature related to brick-making process

Characteristics of fluoride emission from 12 soils at temperatures of 400-1,100 degrees C related to the brick-making process were studied. The results obtained in this study indicate that fluoride emission as gaseous HF and SiF4 was related to the firing temperature, soil total fluoride content, soil composition and calcium compounds added to soils. Soils began to release fluoride at temperatures between 500 and 700 degrees C. Marked increases of the average fluoride mission rate from 57.2% to 85.4% of soil total fluoride were noticed as the heating temperature was increased from 700 to 1,100 degrees C. It was found that the major proportion (over 50%) of the soil total fluoride was emitted from soils at approximate 800 degrees C. The amount of fluoride released into the atmosphere when heated depended on the total fluoride contents in the soils. Correlation analysis showed that the soil composition, such as cation exchange capacity, exchangeable calcium and CaCO3, had some influence on fluoride emission below 900 degrees C, but had no influence at temperatures above 900 degrees C. Addition of four calcium compounds (CaO, CaCO3, Ca(OH)2, and CaSO4) at 1.5% by weight raised the temperature at which fluoride began to be released to 700 degrees C. The greatest decrease in fluoride emission among the four calcium compound treatments was found with CaCO3.

Distribution characteristics of fluoride and aluminum in soil profiles of an abandoned tea plantation and their uptake by six woody species

Distribution characteristics of fluoride (F) and aluminum (Al) in soil profiles of an abandoned tea plantation in Hong Kong and their uptake by six woody species namely Camellia sinensis, Melastoma affine, Sterculia lanceolata, Ardisia crenata, Acacia formosa and Machilus thunbergii were investigated. C. sinensis accumulated both F (656 mg/kg in the leaves) and Al (8910 mg/kg in the leaves). M. Affine only accumulated Al (9932 mg/kg in the leaves), while S. lanceolata, A. crenata, A. formosa and M. Thunbergii were Al (26-115 mg/kg in the leaves) and F (20-25 mg/kg in the leaves) excluders. Water-soluble F and Al contents accumulated in surface soils (especially 0-3 cm) and decreased with depth along soil profiles: A layers (2.0 +/- 0.6 and 31 +/- 5.8 mg/kg) > B layers (1.5 +/- 0.2 and 27 +/- 3.5 mg/kg) > C layers (1.3 +/- 0.2 and 20 +/- 2.7 mg/kg), respectively. The water-soluble, NH4Ac-extractable and HCl-extractable F in soil profiles were significantly correlated (P < .01). F concentrations in all soil layers (n = 51) of soil profiles (n = 17) were significantly correlated (P < .01) to Al concentrations in terms of water-soluble Al/F, HCl-extractable Al/F and NH4Ac-extractable Al/F, due to the formation of Al-F complexes in soil. F contents extracted with deionized water (pH = 6.68), 1 mol/l HCl and 1 mol/l NH4Ac in soil could be used to predict F concentrations in the leaves, stems and roots of the six plants.

Anatomical subdivisions of the stomach of the Bactrian camel (Camelus bactrianus)

Twenty stomachs of Bactrian camels (Camelus bactrianus) were studied by gross dissection. Based on the configuration of the stomach and the structure of the mucous membrane, the stomach was divided into three ventricles that differ from the arrangement described for ox and sheep. The first and second ventricles of the proventriculus of camel form one stomach rather than two different stomachs. These ventricles of the proventriculus do not correspond to the rumen and reticulum of ox and sheep. The third ventricle appears to be the abomasum. One part of the abomasum has reticular mucosal folds that indicate it is not the reticulum. A second part of the abomasum has longitudinal mucosal folds suggesting it is not the omasum. Three glandular sac areas associated with the preventriculus and abomasum are also described.

Gross anatomy of the accessory nerve and vagus nerve of the head and cranial neck region in the Bactrian camel

Seven heads and necks of Bactrian camels were dissected to investigate the origin, course, branches and distribution of the accessory nerve and vagus nerve in the cranial cervical region. The spinal root and external branch of the accessory nerve were not present, but there was a delicate communicating branch between the dorsal root of the first cervical nerve and the root of the vagus nerve. The sternocephalic muscle was innervated by the second cervical nerve while the brachiocephalic and trapezius muscles were supplied by the sixth and seventh cervical nerves. In the head and cranial cervical region of the Bactrian camel the vagus nerve gave off the auricular branch, pharyngeal branch, cranial laryngeal nerve, a common trunk to the larynx, oesophagus and trachea, and some communicating branches connecting with the glossopharyngeal, hypoglossal, first cervical nerves and the cranial cervical ganglion.

The gross anatomy of the cranial cervical ganglion and its branches in the Bactrian camel (Camelus bactrianus)

Ten specimens of the head and neck of the Bactrian camel (Camelus bactrianus) were dissected to study the situation, arrangement and branches of the cranial cervical ganglion (ganglion cervicale craniale). The ganglion was a greyish fusiform structure, averaging 15-20 mm in length, 4-6 mm in width and 3 mm in thickness, located on the rostro-lateral surface of the longus capitis and covered by the mandibular gland. The branches of the cranial cervical ganglion included the internal carotid nerve, external carotid nerve, jugular nerve and the branches connecting with the glossopharyngeal, vagus, hypoglossal and first cervical nerves.

[Phenomenon of intrinsic rhythm of luteinizing hormone release from isolated anterior pituitary gland of female rat]

The intrinsic nature of rthymic release of luteinizing hormone (LH) of isolated human and rat anterior pituitary gland reported independently by Macro Gambacciani and Xie in 1987 can be more directly demonstrated by a computer programme of Time Series-HSY Hidden Periodic Analytic Approach for continuous monitoring the LH output of the perfusate from a perfusion system with in vitro anterior pituitary of SD female rat. The results are as follows: (1) Under various reproductive conditions the average frequency (min/cycle) and amplitude (ng/ml) of the intrinsic rhythm of LH release were quite different: In proestrous group the frequency and amplitude were the highest, being intermediate in the ovariectomized group and lowest in the lactation group. (2) The intrinsic rhythm of LH release could be changed by either peptide or steroid hormones. In proestrous group with 30 min of gonadotropin-releasing hormone (GnRH), stimulation would reduce both frequency and amplitude. In case of lactation, the frequency was unchanged, but amplitude lowered, while in the ovariectomized rat pituitary, the 30 min GnRH stimulation decreased the frequency of release only. The intrinsic rhythm of the LH release could also be influenced by steriod hormones (Ru486 and Anordrin). With 120 min before removal of the anterior pituitary gland the rats receiving i.m. injection of Ru486 (2 mg/kg bw) or Anordrin (2 mg/kg), the results showed that Ru486 decreased frequency, while Anordrin decreased only the frequency to a less extent, both without amplitude affected. (3) Verapamil and EGTA added to the perfusion system did not abolish but only decreased the rhythmic phenomenon by using proestrous pitutary. This suggests that participation of Ca2+ may take place in the intrinsic release of LH. The above results indicated that the intrinsic rhythm of LH release of isolated anterior pituitary gland is different from various reproductive hormonal conditions and capable of being modified by exogenous hormones. The physiological function of the intrinsic rhythm of LH release of anterior pituitary gland remains to be elucidated.