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Background:Plant-derived natural compounds have a unique molecular structure and rich biological activity, hence, they are treated as important raw materials for the development of drugs.Methods:A natural compound (-)-β-pinene was used as a raw material, and twenty-six novel derivatives with amide or acylthiourea groups were synthesized based on the molecular hybridization method. In vitro antitumor activity of these derivatives on human breast cancer cell line MCF7 and human colon cancer cell line SW1116 were tested by MTT method. The effects of the synthesized derivatives on the morphology of MCF7 and SW1116 were observed by fluorescent inverted microscope.Results:The preliminary structure-activity relationship analysis demonstrates that the position and species of substituents on the aromatic ring of derivatives have an effect on the antitumor activity of derivatives. Observation of the cell morphology reveals that derivatives with antitumor activity can lead to rounding of the cell morphology, a decrease in cell volume and cell density, and ultimately inhibition of the proliferation of MCF7 and SW1116 cells. The antitumor activity evaluation results show that among these derivatives, compounds 5c, 5e, 5h, 7c, 7b and 7e exhibit good antitumor activity against MCF7, and compounds 5c, 5e, 5h and 7j exert moderate antitumor activity against SW1116.Conclusion:This study hopes to promote the high value-added utilization of natural compounds β-pinene and the development of novel antitumor drugs.

Summary Background The management of latent Mycobacterium tuberculosis infection is a new priority action for the WHO End Tuberculosis (TB) Strategy. However, national guidelines on latent tuberculosis infection testing and treatment have not yet been developed in China. Here, we present the results from the 2-year follow-up of a study that aimed to track the development of active disease in individuals with latent tuberculosis infection, identify priority populations for latent infection management, and explore the most suitable latent infection diagnostic approach. Methods A population-based multicentre prospective study was done in four sites in rural China, between 2013 and 2015. The baseline survey in 2013 measured the prevalence of latent tuberculosis infection using QuantiFERON-TB Gold In-Tube (QFT) and tuberculin skin test (TST) in eligible participants. During the follow-up phase between 2014–15, we assessed individuals who had tuberculosis infection at baseline (QFT-positivity or TST tuberculin reaction size [induration] of ≥10 mm) for the development of active disease through active case finding. Eligible participants included in follow-up survey had a birth date before June 1, 2008 (5 years or older in 2013), and continuous residence at the study site for 6 months or longer in the past year. Participants with current active tuberculosis at baseline survey were excluded. Findings Between Sept 1, 2013, and Aug 31, 2015, 7505 eligible participants (aged 5 years or older) were included in tuberculosis infection test positive cohorts (4455 were QFT positive, 6404 had TST induration ≥10 mm, and 3354 were positive for both tests) after baseline examination. During the 2-year follow-up period, 84 incident cases of active tuberculosis were diagnosed. Of participants who developed active tuberculosis, 75 were diagnosed with latent infection by QFT, 62 were diagnosed by TST, and 53 were diagnosed by both tests. An incidence rate of 0·87 (95% CI 0·68–1·07) per 100 person-years was observed for individuals who tested positive with QFT, 0·50 (0·38–0·63) per 100 person-years for those who tested positive with TST (p Interpretation Our results suggest that high-risk populations in communities in rural China, such as individuals at a high risk of disease reactivation from previous tuberculosis, should be targeted for latent infection screening and treatment with an interferon-γ releasing assay rather than a TST. Funding National Science and Technology Major Project of China, Program for Changjiang Scholars and Innovative Research Team in University of China, CAMS Innovation Fund for Medical Sciences, and Sanming Project of Medicine in Shenzhen.

Rationale Boride compounds hold promise for broad applications in the field of optoelectronics due to their high-temperature resistant, corrosion resistant and antioxidant properties. In order to reveal the formation mechanism of alkali and alkaline earth metal doped boron clusters, theoretical studies of these systems are required. Methods All the possible geometrical structures of BeBn+ clusters (n = 1–8) were optimized at the B3LYP/6–311+G(d) level; the harmonic vibration frequencies were obtained to examine the true stability and give the zero-point vibration energy at that theoretical level. The single point energies of all the structures were computed at the CCSD(T)/aug-cc-pVDZ level. For the most stable structures, the average binding energy (Eb), the fragmentation energy (EF) and second-order difference of total energy (Δ2E) were used to evaluate the relative stability of clusters. Results Most of the BeBn+ clusters are planar in structure; the B atoms tend to aggregate to form a boron ring, and the coordinating Be atoms are on the periphery of the clusters. The fragmentation energy and second-order difference of total energy show that there is an obvious odd-even alteration as n increases, and local-maxima when n is odd. Conclusions A systematic theoretical investigation on the geometries, stabilities and electronic properties of BeBn+ clusters has been carried out where n = 1–8. The results provide a useful reference for understanding the formation mechanism and stability of these clusters, as well as guidance for finding larger size clusters.

An anionic polyol (MPP) dispersion was prepared by introducing maleopimaric acid (MPA) into polyester polyol chain through esterification reaction. The influences of catalyst content, molar ratio of alcohol to acid, 5-sulfoisophtalic acid sodium salt (5-SSIPA) content and MPA content on particle size, stability and rheological property of MPP dispersion were investigated. The optimized conditions for the synthesis of stable MPP dispersion were identified as 1 wt% catalyst content, 1.4:1 molar ratio of alcohol to acid, 2.86 wt% 5-SSIPA content, and 15 wt% MPA content. The MPP dispersion was then applied to the preparation of a novel maleopimaric acid-based two-component waterborne polyurethane (2K-WPU) coating. Incorporating MPA into MPP dispersion leaded to the maleopimaric acid-based 2K-WPU coating with improved tensile strength, gloss, pencil hardness, water resistance and ethanol resistance. The results suggested that MPP dispersion provided a potential application in the field of 2K-WPU coating.

Twelve (+)-nopinone-based 2-amino-3-cyanopyridines 4a—l were synthesized from (—)-β-pinene. The structures of these compounds were characterized by FT-IR, 1H NMR, and ESI-MS. All the compounds were tested for their anticancer activity against lung cancer cell line A549, gastric cancer cell line MKN45 and breast cancer cell line MCF7 by MTT method, respectively. The results showed that compounds 4f, 4j and 4k had promising anticancer activity against these cancer cell lines, in particular, compound 4f exhibited broad-spectrum and highly efficient anticancer activity against cell lines A549, MKN45 and MCF7 with IC50 of 23.78, 67.61 and 53.87 μmol·L-1, respectively. The preliminary analysis of the structure activity relationship implied that the Br or Cl substituted group of the benzene ring in these derivatives significantly contributed to the anticancer activity.

Degradation mechanisms of substituted phenyltrimethylammonium cations were investigated through density functional theory (DFT) calculations performed at the B3LYP/6-311++G (2d, p) level. Several substituents and their positions on the benzene ring were changed in order to explore the relation between the orientation effect and the stability of the substituted phenyltrimethylammonium cations. The results of the DFT calculations indicated that the calculated energy barriers are raised when the electron-donating substituents are at the ortho and para positions of the benzene ring. Specifically, the calculations showed that the double-(CH 3 ) 2 N-substituted phenylTMA+ is more stable than the double-(CH 3 ) 2 N-substituted benzylTMA+. The highest increase in ΔG ≠ was 3.7 kcal/mol and resulted from the triple (CH 3 ) 2 N-substitution of phenylTMA+. These results elucidate the effects of substituents on the degradation of model cations and provide a reference for their potential use in anion-exchange membranes.

Summary Background Prophylactic treatment of individuals with latent Mycobacterium tuberculosis infection is an essential component of tuberculosis control in some settings. In China, the prevalence of latent tuberculosis infection, and preventive interventions against this disease, have not been systematically studied. We aimed to assess the prevalence of latent tuberculosis and its associated risk factors in rural populations in China. Methods Between July 1, and Sept 30, 2013, we undertook a baseline survey of a population-based, multicentre, prospective cohort study of registered residents (≥5 years old) at four study sites in rural China. Eligible participants were identified by door-to-door survey with a household sampling design. We screened participants for active tuberculosis and history of tuberculosis then used a tuberculin skin test and an interferon-γ release assay (QuantiFERON [QFT]) to test for latent infection. We used odds ratios (ORs) and 95% CIs to assess variables associated with positivity of QFT and tuberculin skin tests. Findings 21 022 (90%) of 23 483 eligible participants completed a baseline survey. Age-standardised and sex-standardised rates of skin-test positivity (≥10 mm) ranged from 15% to 42%, and QFT positivity rates ranged from 13% to 20%. Rates of positivity for the tuberculin skin test and the QFT test were low in study participants younger than 20 years and gradually increased with age (p for trend Interpretation On the basis of findings showing that the performance of the tuberculin skin test might be affected by various factors including BCG vaccination and age, our results suggest that the prevalence of latent tuberculosis in China might be overestimated by skin tests compared with interferon-γ release assays. Funding The National Science and Technology Major Project of China, the Program for Changjiang Scholars and Innovative Research Team in University of China.

The radical–radical reaction mechanisms of CH 3 O 2 + F have been investigated theoretically at the CCSD (T)//B3LYP/6-311++G (3df, 3pd) level. The calculations reveal that the reaction should be taking place both on the singlet and triplet potential surfaces. On the singlet potential surface, the most favorable channel starts with a barrierless addition of F to CH 3 O 2 leading to 1 im2 (CH 3 OOF), and then the adduct 1 im2 goes through an H transfer forming the products CH 2 OO and HF. On the triplet potential surface, DFT calculations show that the dominant products are CH 2 OO and HF.

The preparation, characterization, and environmental application of β-cyclodextrin/citric acid/wood flour (β-CD/CA/WF) graft copolymer wood-based biosorbent for methylene blue (MB) biosorption were investigated in this paper. The Fourier transform infrared spectroscopy and the technique of phenolphthalein probe were used to characterize the grafting β-CD. Furthermore, the biosorption behavior of MB on β-CD/CA/WF graft copolymer was studied under various conditions of pH, contact time, and initial MB concentration. The results indicated that the biosorption of MB was dependent on both the initial MB concentration and the initial pH. Langmuir isotherm model fitted the isotherm data better than the Freundlich model. The adsorption kinetics followed the pseudo-second-order kinetic model, and intraparticle diffusion was one of the effective rate-controlling steps for the entire biosorption period. Equilibrium and kinetic results have implied that β-CD/CA/WF graft copolymer could be considered as a promising material for the adsorption of dye from aqueous solutions.

Prospective population data on the incidence of tuberculosis (TB) infection has been sparsely reported in the global literature.A population-based prospective study was conducted in rural China to investigate the annual risk of TB infection, and its persistence using serial tuberculin skin tests (TSTs) and an interferon-γ release assay. In total, 13 580 eligible participants from four rural sites, identified as TST negative (The annual conversion rate of QFT among the study sites ranged between 2.1% and 4.9% (average 3.1%), and the incidence of TST conversion ranged between 6.0% and 31.1% (average 14.5%). During the second year's follow-up, infection persistence was investigated using 390 subjects with QFT conversions. Among them, 49.7% (164 out of 330) were found to be consistently QFT positive. Both the conversion and the persistence of QFT positivity were found to be significantly increased with increasing age.In conclusion, the annual TB infection rate was suggested to be ∼1.5% based on persistent positive results after QFT conversion in rural China. Therefore, infection control among those high-risk populations, including the elderly, should be prioritised for TB control in China.

Poplar wood flour, a low-cost and abundantly available material, was modified by grafting β-cyclodextrin (β-CD) in the presence of citric acid or 1,2,3,4-Butanetetracarboxylic acid, aiming to expand the application of wood flour. The products were characterized by Fourier transform infrared spectroscopy and the technique of phenolphthalein probe. The grafting conditions of β-CD onto wood flour including curing temperature, β-CD concentration in impregnation solution and catalyst were also evaluated by the technique of phenolphthalein probe. Besides, eugenol (EG), an antibacterial fragrant guest molecule, was loaded on the modified wood flour by lyophilization, and its release characteristics were investigated by Thermo-gravimetric. The results revealed that the modified wood flour material had a thermo-protective effect on the volatilization of EG and the encapsulated EG content was reached to 1.31 %, which could demonstrate a potential application in the finishing and packing areas.

Maleopimaric acid (MPA), an important rosin derivative, was used to partially substitute isophthalic acid for the preparation of an anionic polyol (MPP) dispersion. The MPP dispersion was then applied to prepare a novel maleopimaric acid-modified two-component waterborne polyurethane (MPP-2K-WPU). The influences of NCO:OH molar ratio on the thermal properties, water absorption, surface free energy, and application properties of MPP-2K-WPU films were investigated. With increasing NCO:OH molar ratio, the thermal stability, pencil hardness, and ethanol resistance of MPP-2K-WPU films were improved, but the water resistance was enhanced firstly and then weakened. The surface free energy of MPP-2K-WPU films mainly depended on the dispersion interaction which was related to the structure of macromolecules. In addition, compared with the control sample of PP-2K-WPU(1.5:1) film, the MPP-2K-WPU(1.5:1) film exhibited improved thermal stability, water resistance, gloss, pencil hardness, and ethanol resistance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43292.

The binding constants (Ka) of phenolphthalein/β-cyclodextrin, phenolphthalein/(2-hydroxypropyl)-β-cyclodextrin, and phenolphthalein/(2,6-dimethyl)-β-cyclodextrin complexes were measured by ultraviolet-visible spectrophotometer. By regression of van't Hoff plot, thermodynamic parameters (ΔH° and ΔS°) of these complexes' formation were obtained. Based on these parameters, steric hindrance influence, spontaneous and enthalpically driven process for the interaction of phenolphthalein with cyclodextrins were further proved, and phenolphthalein, as a probe molecule, was used to determinate cyclodextrins' content due to less than 0.6% relative standard deviation of these quantifications and recoveries with the range of 90 ∼ 103%. Using microfiltration technique, the detection phenolphthalein probe technique was applied on the determination of surface activity of cyclodextrins grafting cellulose beads by different polycarboxylic acids, and the results exhibit the real encapsulation activity of the cyclodextrins containing these spherical functional biomaterials. Copyright © 2011 John Wiley & Sons, Ltd.

A solid state eugenol/β-cyclodextrin inclusion complex (EG/β-CD) was prepared by lyophilization method and characterized by Powder X-ray Diffraction (XRD) and Fourier Fransform Infrared Spectroscopy (FTIR). UV–Vis spectrometer was used to determine the EG content encapsulated in the complex. In order to estimate the release characteristics of the EG/β-CD powder, Avrami’s equation and Thermogravimetric (TG) analyzer were, respectively, used. The loss percentage of EG was no more than 10 wt% for 4 week exposing at 25 °C and 75% humidity, and the release of EG is controlled by a combination mechanism of diffusion and first-order mode. TG results not only proved the thermo stability of the EG in EG/β-CD complex, but also clarified the thermal decomposition behaviors of the EG/β-CD. The antibacterial activity of the EG/β-CD complex was investigated using agar cup-plate diffusion method and bacterial strains of Escherichia coli, Salmonella paratyphi B, and Staphyloccocus aureus were used. The results indicated that EG/β-CD had a selective antimicrobial active against Escherichia coli.