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The synthesis of graphene-like carbon nitride has been a new research hotspot in the field of two-dimensional functional materials due to its similar structural characteristics to graphene and outstanding properties covering photocatalysis and lubrication and so on. Herein, the research progress of the microwave irradiation synthesis of graphene-like carbon nitride was discussed. Based on the comparison to the traditional preparation approaches including high-temperature oxidation corrosion, liquid phase ultrasonic exfoliation and thermal polymerization, etc., the advantages of microwave irradiation synthesis were analyzed. At the same time, one can find that by means of using high-energy microwave instrument and microwave absorbents covering graphite powders and short carbon fibers that possess excellent microwave energy absorption ability, the transferring and absorption efficient of energy as well as the non-steady degree of the synthesis reactions occurred in the microwave electromagnetic field can be enhanced, is consequently beneficial to the achievement of novel products with special morphology and structure.

Microwave synthesis has many advantages covering rapid, high-efficient, environmentally-friendly etc. Herein, graphene-like carbon nitride nanosheets (g-C3N4-NS) were successfully prepared by high-energy microwave heating method using melamine and carbon fibers as precursor and microwave absorber, respectively. The as-synthesized samples were investigated via various analytic techniques including X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and fourier transform infrared spectroscopy (FT-IR). Results show that the g-C3N4-NS sample prepared by microwave heating exhibits the obvious feature of graphene-like ultra-thin nanosheets in comparison with sample synthesized by conventional thermal polycondensation. Meanwhile, compared with graphene-like carbon nitride nanosheets prepared by other approaches including ultrasonic exfoliation and oxidation etching methods, the sample synthesized by microwave heating has smooth, flat and strong rigidity surface.

Background: The aerial parts of Peganum harmala L. (APP) is a well-known and effective herbal medicine in China, and has been commonly used for treating various ailments, including cough and asthma. Objectives: To evaluate the antitussive, expectorant, and bronchodilating effects of the quinazoline alkaloids ([+ or -])-vasicine(VAS), deoxyvasicine (DVAS) (both isolated from the alkaloid fraction of APP) and (±)- vasicinone (VAO) (synthesized from VAS). Methods: The three quinazoline alkaloids were tested as antitussive on cough models in mice and guinea pigs. VAO was synthesized from VAS via the oxidation of hydrogen peroxide. VAS, VAO, and DVAS were orally administered at dosages of 5,15, and 45 mg/kg. Cough in these models was induced by ammonia, capsaicin, and citric acid. Phenol red secretion experiments in mice were performed to evaluate the expectorant activity of the alkaloids. Bronchodilating effects were evaluated by using a bronchoconstrictive induced by acetylcholine chloride and histamine in guinea pigs. Results: In antitussive tests, VAS, VAO, and DVAS significantly inhibited coughing frequency and prolonged the cough latency period in animals. At the highest doses tested (45 mg/kg), they showed antitussive activities similar to codeine phosphate (30 mg/kg) in mice and guinea pigs. Expectorant evaluation showed that VAS, VAO, and DVAS could significantly increase phenol red secretion in mice by 0.54-, 0.79- and 0.97-fold, by 0.60-, 0.99-, and 1.06-fold, and by 0.46-, 0.73-, and 0.96-fold, respectively, at dosages of 5,15, and 45 mg/kg compared with the control (0.5% CMC-Na, 20 ml/kg). Ammonium chloride at 1500 mg/kg increased phenol red secretion in mice by 0.97-fold compared with the control. Bronchodilation tests showed that VAS, VAO, and DVAS prolonged the pre-convulsive time for 28.59%, 57.21%, and 29.66%, respectively, at a dose of 45 mg/kg in guinea pigs, whereas aminophylline prolonged the pre-convulsive time by 46.98% compared with pretreatment. Conclusions: Quinazoline alkaloids VAS, VAO, and DVAS have significant antitussive, expectorant, and bronchodilating activities. VAS, VAO, and DVAS are the active ingredients in APP, which can be used to treat respiratory disease. Keywords: Peganum harmala L Antitussive Expectorant Bronchodilating Quinazoline, Introduction Cough is among the common symptoms associated with many respiratory diseases, such as asthma, chronic bronchitis, and pneumonia (Ce et al., 2009; Irwing and Madison, 2000). These respiratory diseases [...]

Preliminary assessment of rabies virus neutralizing activity, safety and immunogenicity of a recombinant human rabies antibody (NM57) compared with human rabies immunoglobulin (HRIG) in Chinese healthy adults. Subjects were randomly (1:1:1) allocated to Groups A (20 IU/kg NM57), B (40 IU/kg NM57), or C (20 IU/kg HRIG). One injection was given on the day of enrollment. Blood samples were collected on days –7 to 0 (pre-injection), 3, 7, 14, 28, and 42. Adverse events (AEs) and serious AEs (SAEs) were recorded over a period of 42 days after injection. All 60 subjects developed detectable rabies virus neutralizing antibodies (RVNAs) (> 0.05 IU /mL) on days 3, 7, 14, 28, and 42. The RVNA levels peaked on day 3 in all three groups, with a geometric mean concentration (GMC) of 0.2139 IU/mL in Group A, 0.3660 IU/mL in Group B, and 0.1994 IU/mL in Group C. At each follow-up point, the GMC in Group B was significantly higher than that in Groups A and C. The areas under the antibody concentration curve over 0–14 days and 0–42 days in Group B were significantly larger than those in Groups A and C. Fifteen AEs were reported. Except for one grade 2 myalgia in Group C, the other 14 were all grade 1. No SAEs were observed. The rabies virus neutralizing activity of 40 IU/kg NM57 was superior to that of 20 IU/kg NM57 and 20 IU/kg HRIG, and the rabies virus neutralizing activity of 20 IU/kg NM57 and 20 IU/kg HRIG were similar. Safety was comparable between NM57 and HRIG. [ABSTRACT FROM AUTHOR]

Hypoxia-inducible factor l[alpha] (HIF-l[alpha]) transcriptionally activates multiple genes, which regulate metabolic cardioprotective and cross-adaptive mechanisms. Hypoxia and several other stimuli induce the HIF-1[alpha] signaling cascade, although little data exist regarding the stress threshold for activation in heart. We tested the hypothesis that relatively mild short-cycle hypoxia, which produces minimal cardiac dysfunction and no sustained or major disruption in energy state, can induce HIF-1[alpha] activation. We developed a short-cycle hypoxia protocol in isolated perfused rabbit heart to test this hypothesis. By altering cycling conditions, we identified a specific cycle with [O.sub.2] content and duration that operated near a threshold for causing functional injury in these rabbit hearts. Mild short-cycle hypoxia for 46 rain elevated HIF-l[alpha] mRNA and protein within 45 min after reoxygenation. Expression also increased for multiple HIF-1[alpha] target genes, such as VEGF and heme oxygenase 1. After mild hypoxia, VEGF protein accumulation occurred, although HIF-l[alpha] and VEGF protein accumulation were suppressed after more severe hypoxia, which also caused depletion of ATP and nondiffusible nucleotides. In summary, these results indicate that mild near-threshold hypoxia induces HIF-l[alpha] cascade, but more severe hypoxia suppresses protein accumulation for this transcription factor and the target genes. Posttranscriptional suppression of these proteins occurs under conditions of altered energy state, exemplified by ATP depletion. ATP; heine oxygenase; oxygen consumption; reoxygenation; vascular endothelial growth factor