Hydrolytic dehydrogenation of NH3BH3 catalyzed by ruthenium nanoparticles supported on magnesium–aluminum layered double-hydroxides

Ammonia borane (AB, NH₃BH₃) with extremely high hydrogen content (19.6 wt%) is considered to be one of the most promising chemical hydrides for storing hydrogen. According to the starting materials of AB and H₂O, a hydrogen capacity of 7.8 wt% is achieved for the AB hydrolytic dehydrogenation system with the presence of a highly efficient catalyst. In this work, ruthenium nanoparticles supported on magnesium–aluminum layered double hydroxides (Ru/MgAl-LDHs) were successfully synthesized via a simple method, i.e., chemical reduction. The effect of Mg/Al molar ratios in MgAl-LDHs on the catalytic performance for AB hydrolytic dehydrogenation was systematically investigated. Catalyzed by the as-synthesized Ru/Mg₁Al₁-LDHs catalyst, it took about 130 s at room temperature to complete the hydrolysis reaction of AB, which achieved a rate of hydrogen production of about 740 ml s⁻¹ g⁻¹. Furthermore, a relatively high activity (TOF = 137.1 mol_H2 mol_Ru⁻¹ min⁻¹), low activation energy (E_a = 30.8 kJ mol⁻¹) and fairly good recyclability of the Ru/Mg₁Al₁-LDHs catalyst in ten cycles were achieved toward AB hydrolysis for hydrogen generation. More importantly, the mechanism of AB hydrolysis catalyzed by Ru/MgAl-LDHs was simulated via density functional theory. The facile preparation and high catalytic performance of Ru/MgAl-LDHs make it an efficient catalyst for hydrolytic dehydrogenation of AB.

Ru/MgAl-LDHs catalyst was successfully prepared, which exhibited higher catalytic activity and lower activation energy toward the hydrolysis of ammonia borane for hydrogen production.     

Molecular simulations of gas transport in hydrogenated nitrile butadiene rubber and ethylene–propylene–diene rubber

Diffusion and sorption of five gases (H₂, N₂, O₂, CO₂, CH₄) in hydrogenated nitrile butadiene rubber (HNBR) and ethylene–propylene–diene rubber (EPDM) have been investigated by molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) simulations. The diffusion coefficients of gas molecules in HNBR and EPDM are well correlated with the effective penetrant diameter except for CO₂. CO₂ shows a lower diffusion coefficient due to its linear shape. Additionally, the favorable interaction between CO₂ and HNBR is another factor for its lower diffusion coefficient in HNBR. HNBR shows lower diffusion coefficients than EPDM. This is because the polar –CN groups in HNBR chains increase interchain cohesion and result in tight intermolecular packing, low free volume and poor chain mobility, which decreases the diffusion coefficients of HNBR. The solubility coefficients of CH₄, O₂, N₂ and H₂ in HNBR are lower than those in EPDM, which is a result of the weak HNBR–penetrant interactions and low free volume of HNBR. However, the solubility coefficient of CO₂ in HNBR is higher than in EPDM. This is attributed to the strong interaction between CO₂ and HNBR. H₂, O₂, N₂ and CH₄ show lower permeability coefficients in HNBR than in EPDM, while CO₂ has higher permeability coefficients in HNBR. These molecular details provide critical information for the understanding of structures and gas transport between HNBR and EPDM.

Diffusion and sorption of five gases (H₂, N₂, O₂, CO₂, CH₄) in HNBR and EPDM were explored by MD and GCMC simulations.     

Two rare {M2(MoO4)2}n chain-containing molybdate-based metal–organic complexes with a bis-pyrazole-bis-amide ligand: fluorescent sensing and photocatalysis performance

By introducing a bis-pyrazole-bis-amide ligand, N,N′-bis(1H-pyrazole-4-carboxamide)-1,4-benzene (L), two molybdate-based metal–organic complexes containing {M₂(MoO₄)₂}_n (M = Co, Zn), [Co₂L₂(MoO₄)₂]·H₂O (1), [Zn₂L₂(MoO₄)₂]·H₂O (2), have been prepared under hydrothermal/solvothermal conditions. X-ray diffraction analyses reveal that both 1 and 2 are isostructural. An interesting structural feature is that a kind of {M₂(MoO₄)₂}_n chain could be found in 1 and 2, although different raw materials [Mo₇O₂₄]⁶⁻ and [PMo₁₂O₄₀]³⁻ anions were utilized. Then these chains are further linked by L ligands into a two dimensional (2D) structure. The title complexes represent the first examples containing {MoO₄} units and pyrazole-/or amide-derivative ligands. Complexes 1 and 2 exhibit distinct performances due to different metal centers, with 2 acting as a fluorescent sensor for Fe³⁺, MnO₄⁻, CrO₄²⁻ and Cr₂O₇²⁻, but 1 being a better photocatalyst towards degradation of cationic dyes methylene blue (MB) and neutral red (NR).

Two molybdate-based complexes containing {M₂(MoO₄)₂}_n (M = Co or Zn) chains were obtained, which demonstrated different properties: excellent photocatalytic degradation performance of cationic dyes for 1 and fluorescence sensing behavior for 2.     

Temperature controlled condensation of nitriles: efficient and convenient synthesis of β-enaminonitriles, 4-aminopyrimidines and 4-amidinopyrimidines in one system

A series of β-enaminonitriles, 4-aminopyrimidines and 4-amidinopyrimidines were synthesized by condensation of organonitriles in one system. A wide variety of compounds were obtained in good to excellent yields by simply controlling the reaction temperature. The base-induced transformation process is easy for production. The scope and versatility of the method have been successfully demonstrated with 72 examples. The flexible and diversified characteristics of nitriles were introduced based on electronic effect, steric effect, position of substituted groups and intermolecular hydrogen bonding. An updated reaction mechanism is proposed based on the study of the stoichiometric reaction conditions at variable temperature, and on the investigation of products with cis–trans configuration transformation.

A wide variety of β-enaminonitriles, 4-aminopyrimidines and 4-amidinopyrimidines were simply synthesized from organonitriles by controlling the reaction temperature.     

S-doped porous carbon anode with superior capacity for high-performance sodium storage

Heterogeneous carbon-based materials with high porosity are attracting increased attention for energy storage due to their enhanced capacity and rate performance. Herein, we report a sulfur-doped porous carbon material, which is achieved by spray-drying and subsequent sulfuration. The porous structure can provide vast diffusive tunnels for the fast access of electrolytes and sodium ions. Also, the S–C bond increases the electrical conductivity of the carbon frameworks and offers excessive reaction sites for sodium-ion storage. The elaborated carbon architecture enables a high capacity of 370 mA h g⁻¹ at 0.5 A g⁻¹ and provides an excellent rate performance for long-term cycling (197 mA h g⁻¹ at 2.0 A g⁻¹ for 650 cycles). Considering the scalable and facile spray-pyrolysis preparation route, this material is expected to serve as a low-cost and environmentally friendly anode for practical sodium-ion batteries.

A novel S-doped porous carbon material with superior sodium storage performance was obtained through spray-drying and subsequent sulfur doping treatment.     

C1–2 transarticular screws combined with C1 laminar hooks fixation: a modified posterior atlantoaxial fixation technique and outcome in 72 patients

Purpose

To retrospectively evaluate the outcome of C1–2 transarticular screws combined with C1 laminar hooks fixation.

Methods

All patients underwent atlantoaxial fixation during a 5-year period. The surgical technique and treatment procedures were intensively reviewed and clinical symptoms, neurological function and imaging appearance were retrospectively evaluated.

Results

The clinical and radiology follow-up indicated a stable arthrodesis and clinical relief from symptoms for all patients. All patients with neurological defects improved an average of 1.33 grade at their most recent clinical assessment, P < 0.05; their average admission ASIA motor score, pin prick score and light touch score improved to an average follow-up ASIA score of 99.80 (99.83 ± 0.38), 111.83 (111.83 ± 0.45), and 111.89 (111.89 ± 0.32), respectively. No neurovascular impairment and case of implant failure were observed.

Conclusions

The C1–2 transarticular screws combined with C1 laminar hooks fixation is a reliable technique for atlantoaxial instability.     

后腹腔镜离断式肾盂成形术的改良及应用效果

目的：探讨后腹腔镜离断式肾盂成形术中输尿管吻合及双J管置人方法的改良及应用效果。方法：2010年6月～2013年1月,对32例肾盂输尿管连接部梗阻（ureteropelvicjunctionobstruction,UPJO）患者实施后腹腔镜离断式肾盂成形术,吻合方法采取两针固定连续缝合法,双J管放置采取Trocar外推置法。观察手术时间、吻合时间、置双J管时间、住院时间、并发症发生率、引流管放置时间等,总结手术技巧,并与前期18例采用间断缝合和双J管经Trocar内放置的后腹腔镜离断式肾盂成形术进行比较。结果：两组手术均获成功。改良手术组和对照组平均手术时间分别为（78．2±16．3）min、（114．7±17．5）min（P〈0．05）,输尿管吻合时间分别为（24．2±4．9）min、（49．4±7．5）min（P〈0．05）,双J管置入时间分别为（3．6±1．0）min、（9．1±2．2）min（P〈0．05）,两组引流管放置时间、住院时间和并发症发生率比较差异无统计学意义（P〉O．05）。改良手术组随访3～30个月,平均9．2个月,B超提示肾积水消失11例,肾积水不同程度减轻21例。结论：后腹腔镜离断式肾盂成形术中采取两针固定连续缝合法吻合,可以降低输尿管吻合难度,缩短手术时间;经Trocar外推置法放入双J管,简便快速。     

Effect of endoplasmic reticulum stress on the activation of high glucose-induced monocytes

Objective To observe the effects of endoplasmic reticulum stress (ERS) on the activation of monocytes induced by high glucose and explore the underlying mechanism. Methods The monocyte cell line THP-1 was stimulated with high glucose, and then treated with molecular chaperone betaine. The levels of glucose regulation protein 78 (GRP78) and p-JNK, which were associated with ERS were detected by real-time PCR and Western blotting. The proliferation of the cell line was detected by MTT method. Transwell and immunofluorescence were applied to observe the chemotaxis and phenotype of cells respectively. Results The levels of GRP78 and p-JNK of THP-1 cells stimulated by high glucose were significantly increased compared with the normal control group (all P＜0.05). The proliferation and chemotactic were also enhanced (all P＜0.05). The number of cells in M1 phenotype was increased remarkably (P＜0.05). All the indexes above could be rescued by betaine. Conclusion The activation of THP-1 cells can be induced by high glucose through ERS, while molecular chaperone betaine can reverse the activation.     

吻合掌侧静脉及保留指甲的指尖再植

目的: 探讨手指指尖离断的治疗方法及临床效果。方法: 2007年10 月至2011年6月治疗13例18指指尖离断患者,其中男9例,女4例;年龄17～45岁,平均26岁。伤后至就诊时间30 min～5 h,断指缺血时间1.5～7 h,均为常温保存。采用吻合掌指静脉及保留指甲的方法进行再植。结果: 13例18 指断指均成活并获随访,术后无血管危象发生。随访时间为3～24个月,平均14个月。患指外形及长度与健指相似,指甲平整,关节活动良好,触、痛觉恢复,两点辨别率3～6 mm,平均5 mm.根据中华医学会手外科学会断指再植功能评定标准评定,优14指,良3指,差1指。结论: 采用吻合掌侧静脉及保留指甲的方法进行指尖再植,不仅可以提高断指成活率还可以恢复良好的外观及功能,是一种理想的方法。     

消积排通散联合手术及电子线治疗瘢痕疙瘩的临床研究

目的：探讨应用消积排通散联合手术及电子线治疗瘢痕疙瘩的,陆床效果。方法：对120例瘢痕疙瘩分3组对比研究,A组行手术＋注射治疗,B组行手术＋电子线治疗,c组行手术＋电子线＋中药治疗。三组患者均经过I～2月一个疗程的治疗,随访观察临床疗效。用统计学方法比较三组患者临床疗效。结果：手术＋电子线＋中药方法治疗的患者疗效稳定,复发几率最低。结论：对于瘢痕疙瘩,消积排通散联合手术及电子线治疗的方法明显优于其他方法,且复发几率降低,患者满意度更好。