Evaluation of Pesticide Toxicity and Chemical Compounds Revealed in Soils of Sikasso and Segou (Mali)

The contaminants of the ground are potentially harmful agents and when they are released in this medium, their persistence becomes an important concern. Because of the expressed interest, a certain number of pesticides and important chemicals and their toxicity are described in this article. The studies went on the determination of the concentration, the lethal amount of the organochlorinated compounds, chemical organophosphates, carbamates and compounds. One summer recorded 3 pesticides in 5 samples of the grounds of Sikasso and Segou (Mali). Their concentration varies from 20 (atrazine) with 45 g/kg of ground. The lethal amounts of the revealed poisons variable from 338 for phtalates to 28.710 mg/kg for hexane (alkane) thus evaluate their impact on the food chain. Organophosphates and the carbamates (insecticidal) involve a reduction of 34.2% of the number of Cyprinus carpio of fresh water. The atrazine contaminates drinking water, but the diuron modifies the behavior and the reproduction of fish by deteriorating their system of olfactive perception of natural substances. Important mortalities of birds are noted around the corn fields of Bougouni treated by the carbofuran. The pesticides involve at the man a reduction in fruitfulness, an increase in the risk of miscarriage of premature birth, congenital malformations and cancers.

Changes in Chemical Composition of Soluble Organic Chemical Compounds during Litters Decomposition into Tropical Forest of Milletia laurentii De Wild

Recent publication attested that in the urban forest of Brazzaville, litter decomposition is faster with almost 45% of initial weight loss than in the dry season, where an average loss of 26% in initial litter weight is noted (Ifo et al., 2018). This study was carried out in the urban forest of Brazzaville to follow the decomposition of some organic compounds/secondary metabolites (reducing Sugars, total Flavonoid and Polyphenols) of the leaves litters of two tropical species Antiaris toxicaria Lesch and Millettia laurentii De Wild. Thin-layer chromatography and spectrophotometric assay of these metabolites were used on the samples of litters collected in the field on various dates of follow-up of the decomposition (0 d, 14 d, 28 d, 42 d, 56 d, 72 d and 84 d). The chromatographic profile of initial litters shows a series of spots on yellow florescence materializing presence of flavonoids, green fluorescence revealing the presence of the acids phenols derived from the cinnamic acid. But the chromatographic profile of the two litters in decomposition after two weeks remains without structural information, being able to characterize the decomposition of the chemical families highlighted in the initial litters. Also, the analysis of quantitative total reducing sugar in the initial litters, gives average concentrations of 64.4, 58.6, 57.5 g EG/kg Ms respectively for the litters of Millettia laurentii De Wild, Antiaris toxicaria Lesch and the mixed litters (Millettia laurentii and Antiaris toxicaria). Comparatively with the other types of litters, the initial average concentrations in phenolic compounds (polyphenols and flavonoids totals) were the highest for the litters of Antiaris toxicaria Lesch (27.3 g EAG/kg Ms and 13.07 g EC/kg Ms) (P = 0.001). The losses of organic chemical compounds are more significant during the first two weeks of experiment than after this period. Antiaris toxicaria Lesch loses on average 43.8 g EG/kg Ms of reducing Sugars, 12.21 g EC/kg Ms of totals flavonoids and 26.4 g EAG/kg Ms of total polyphenols, equivalent to 30% of loss of the initial weight. Average losses of 45.7 g EG/kg Ms were obtained for reducing sugars, 1.5 g EC/kg Ms for totals flavonoids and 8.72 g EAG/kg Ms for totally phenols in for the litters of Millettia laurentii, comparable to 24% in initial weight loss. This study showed on the one hand, the direct link between rainfall and litters decomposition and the losses in weight of the litters resulted in dissolution in the water of the studied compounds.

Cocktail of chemical compounds robustly promoting cell reprogramming protects liver against acute injury

Tissue damage induces cells into reprogramming-like cellular state, which contributes to tissue regeneration. However, whether factors promoting the cell repro- gramming favor tissue regeneration remains elusive. Here we identified combination of small chemical com- pounds including drug cocktails robustly promoting in vitro cell reprogramming. We then administrated the drug cocktails to mice with acute liver injuries induced by partial hepatectomy or toxic treatment. Our results demonstrated that the drug cocktails which promoted cell reprogramming in vitro improved liver regeneration and hepatic function in vivo after acute injuries. The underlying mechanism could be that expression of pluripotent genes activated after injury is further upregulated by drug cocktails. Thus our study offers proof-of-concept evidence that cocktail of clinical com- pounds improving cell reprogramming favors tissue recovery after acute damages, which is an attractive strategy for regenerative purpose.

Technology Development and Production of Certain Chemical Platinum Metals Compounds at JSC ＂Krastsvetmet＂

In recent years JSC "Krastsvetmet" has successfully developed the production of chemically pure compounds of precious metals.Currently methods have been developed and facilities have been provided for industrial production of the following platinum metals compounds:Rhodium(Ⅲ) chloride hydrate,rhodium(Ⅲ) chloride solution,rhodium(Ⅲ) nitrate solution,rhodium(Ⅲ) iodide,rhodium(Ⅲ) sulfate,hydrated rhodium(Ⅲ) oxide,ammonium hexachlororodiate,rhodium(Ⅲ) phosphate solution,rhodium electrolytes;Iridium(Ⅳ) chloride hydrate,iridium(Ⅲ) chloride hydrate,ammonium hexachloroiridate(Ⅳ),hexa chloriridium acid solution,hexachloriridium crystalline acid;Ruthenium(Ⅲ) chloride hydrate,ruthenium(Ⅳ) hydroxide chloride,ruthenium(Ⅳ) hydroxide chloride solution,ammonium hexachlororuthenate,ruthenium(Ⅲ) chloride solution,potassium,diaquaoctachloronitrido diruthenate.The quality of the production meets the requirements of Russian and foreign consumers.

PARTIAL RECONSTITUTION OF BOTANICAL EXTRACT PG102 BY COMBINING CHEMICAL COMPOUNDS KNOWN TO BE PRESENT IN ACTINIDIA ARGUTA: IMPLICATIONS FOR QC OF PHYTOMEDICINES

One of the most important factors limiting the success of plant-derived therapeutics is that these products are generally a mixture containing many different molecules.The compounds responsible for bioactivities and/or clinical effects are also not yet identified.To overcome this hurdle,we investigated whether we can reconstitute bioactivities

MCSPT-A MODIFIED HARD-SPHERE THREE-PARAMETER EQUATION OF STATE FOR THERMODYNAMIC PROPERTIES OF PURE COMPOUNDS

The hard - sphere three - parameter equation of state(CSPT) proposed in the previous paper(Li et al. 1991) was modified by a new temperature relation for the pseudo-critical compressibility ξc and the temperature correction factor α(Tr) of the attractive parameter. Vapor pressures and saturated liquid densities of 105 pure compounds were calculated by the modified version. Results show that correlations of saturated properties at low reduced temperatures and thermodynamic properties in the vicinity of critical region were significantly improved. Furthermore, characteristic parameters of this modified version were generalized by acentric factor ω and critical compressibility Zc to predict saturated liquid densities of 72 polar substances and the latent heat of vaporization for 151 substances including strongly polar compounds with satisfactory results.

Artificial bioconversion of carbon dioxide

CO2 is not only the most important greenhouse gas but also an important resource of elemental carbon and oxygen.From the perspective of resource and energy strategy,the conversion of CO2 to chemicals driven by renewable energy is of significance,since it can not only reduce carbon emission by the utilization of CO2 as feedstock but also store low-grade renewable energy as high energy density chemical energy.Although studies on photoelectrocatalytic reduction of CO2 using renewable energy are increasing,artificial bioconversion of CO2 as an important novel pathway to synthesize chemicals has attracted more and more attention.By simulating the natural photosynthesis process of plants and microorganisms,the artificial bioconversion of CO2 can efficiently synthesize chemicals via a designed and constructed artificial photosynthesis system.This review focuses on the recent advancements in artificial bioreduction of CO2,including the key techniques,and artificial biosynthesis of compounds with different carbon numbers.On the basis of the aforementioned discussions,we present the prospects for further development of artificial bioconversion of CO2 to chemicals.

Occupational exposures and colorectal cancers:A quantitative overview of epidemiological evidence

A traditional belief widespread across the biomedical community was that dietary habits and genetic predisposition were the basic factors causing colorectal cancer.In more recent times,however,a growing evidence has shown that other determinants can be very important in increasing(or reducing) incidence of this malignancy.The hypothesis that environmental and occupational risk factors are associated with colorectal cancer is gaining ground,and high risks of colorectal cancer have been reported among workers in some industrial branches.The aim of this study was to investigate the epidemiologic relationship between colorectal cancer and occupational exposures to several industrial activities,by means of a scientific literature review and meta-analysis.This work pointed out increased risks of colorectal cancer for labourers occupied in industries with a wide use of chemical compounds,such as leather(RR = 1.70,95%CI:1.24-2.34),basic metals(RR = 1.32,95%CI:1.07-1.65),plastic and rubber manufacturing(RR = 1.30,95%CI:0.98-1.71 and RR = 1.27,95%CI:0.92-1.76,respectively),besides workers in the sector of repair and installation of machinery exposed to asbestos(RR = 1.40,95%CI:1.07-1.84).Based on our results,the estimated crude excess risk fraction attributable to occupational exposure ranged from about 11% to about 15%.However,homogeneous pattern of association between colorectal cancer and industrial branches did not emerge from this review.

Polynomials of Degree-Based Indices for Three-Dimensional Mesh Network

In order to study the behavior and interconnection of network devices,graphs structures are used to formulate the properties in terms of mathematical models.Mesh network(meshnet)is a LAN topology in which devices are connected either directly or through some intermediate devices.These terminating and intermediate devices are considered as vertices of graph whereas wired or wireless connections among these devices are shown as edges of graph.Topological indices are used to reflect structural property of graphs in form of one real number.This structural invariant has revolutionized the field of chemistry to identify molecular descriptors of chemical compounds.These indices are extensively used for establishing relationships between the structure of nanotubes and their physico-chemical properties.In this paper a representation of sodium chloride(NaCl)is studied,because structure of NaCl is same as the Cartesian product of three paths of length exactly like a mesh network.In this way the general formula obtained in this paper can be used in chemistry as well as for any degree-based topological polynomials of three-dimensional mesh networks.

Antibacterial enhancement of antibiotic activity by Enterolobium contortisiliquum(Vell.)Morong

Objective: To identify the main chemical classes of compounds from aqueous extract of Enterolobium contortisiliquum(E. contortisiliquum) seed bark and to evaluate its antibacterial activity, as well as its potential to increase the activity of antibiotics against strains of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli.Methods: Different classes of compounds in the aqueous extract of E. contortisiliquum were evaluated based on the visual changes in the coloration and the formation of precipitate after the addition of specific reagents. The antibacterial activity of the extract and its potential to increase of antibiotic activity of antibiotics drugs, gentamicin and norfloxacin was determined by using the microdilution method.Results: Our results demonstrated that the following secondary metabolites were presented in E. contortisiliquum seed bark: flavones, flavonols, xanthones, flavononols,chalcones, aurones, flavones and catechins. The extract itself had very low antibacterial activity against all bacterial strains tested(MIC ≥ 1024 μg/m L), but there was an increase in the antibiotic activity of gentamicin and norfloxacin when combined in the subinhibitory concentration(i.e., MIC/8).Conclusions: Our data suggests that E. contortisiliquum seed bark may be an alternative source for new drugs with the potential to increase antibiotic activity against different strains of bacteria.

Chemical transdifferentiation： closer to regenerative medicine

Cell transdifferentiation, which directly switches one type of differentiated cells into another cell type, is more advantageous than cell reprogramming to generate pluripotent cells and differentiate them into functional cells. This process is crucial in regenerative medicine. However, the cell-converting strategies, which mainly depend on the virus-mediated expression of exogenous genes, have clinical safety concerns. Small molecules with compelling advantages are a potential alternative in manipulating cell fate conversion. In this review, we briefly retrospect the nature of cell transdifferentiation and summarize the current developments in the research of small molecules in promoting cell conversion. Particularly, we focus on the complete chemical compound-induced cell transdifferentiation, which is closer to the clinical translation in cell therapy. Despite these achievements, the mechanisms underpinning chemical transdifferentiation remain largely unknown. More importantly, identifying drugs that induce resident cell conversion in vivo to repair damaged tissue remains to be the end-goal in current regenerative medicine.

Pharmacological potentials of phenolic compounds from Prosopis spp.-a review

The shrub Prosopsis juliflora(Sw.)DC.revealed several medicinal properties due to its different chemical compounds such as alkaloids,flavonoids,terpenoids,saponins and phenolic compounds distributed in different parts of the plant body,such as woody parts(roots,stem,branches and bark)as well as leaves and pollen have been used for the extraction of medically active substances.Prosopsis juliflora containing a diverse group of secondary metabolites has unique and multifactorial medicinal properties.The utilization of this abundant resource provides a viable option for producing bioactive natural products that may serve as lead substances for the chemical and pharmaceutical industries.This review highlights accessible bioactive sources from this plant that are of potential interest for industrial applications.

Comparative analysis of four active compounds of Baikal skullcap and its classical TCM prescriptions according to different clinical curative effects

Objective: A sensitive HPLC-DAD detection method was established for the comparative analysis of the four active compounds(including baicalin, baicalein, wogonoside and wogonin) of Baikal Skullcap and its classical TCM prescriptions according to different clinical curative effects. And analyze the relationship between compatibility of medicines, content and clinical curative effect.Methods: Water extracts were analyzed by high-performance liquid chromatography-diode array detection(HPLC-DAD), using an Agilent extend-C_(18)(4.6 mm×250 mm,5μm) column by using solvent A(0.2% phosphoric acid water) and solvent B(methanol) in the ratio of 52:48(v/v) at a flow rate of 1 ml/min. The column temperature was maintained at 25°C and the detection wavelength was set at 280 nm.Results: In quantitative analysis, the four selected markers showed good regression(R^2>0.999) within test ranges. The average recoveries were between 99.75~100.60% and their RSD values were between 0.97%~1.71%. The proportions of the four chemical compounds for different efficacy were 33.51~35.76: 6.78~6.87: 3.45~3.64: 1; 18.6~23.64: 3.63~4.27: 1.36~1.53: 1; 29.94~31.78: 5.14~5.23: 3.28~3.56: 1; 33.99~41.91:5.83~7.42: 2.83~3.39: 1.Conclusion: Clinical practice of thousands of years have proved that the curative effect of Traditional Chinese Medicine depends on the compatibility of different kinds of medicine material crude slices. According to this study we found that different compatibility of medicines leads to different proportions of the chemical compounds. We assume that there is a certain correlation between therapeutical effect of TCM and compatibility of medicines.

Controlled preparation and self-assembly of NdVO_4 nanocrystals

Phase-pure t-NdVO_4 nanocrystals with different shapes have been synthesized by facile and repeatable hydrothermal methods. The as-synthesized t-NdVO_4 nanoparticles were characterized by various techniques of X-ray diffraction（XRD）. scanning electron microscope（SEM） and transmission electron microscope（TEM）. The growth process and assembly behavior of t-NdVO_4 nanorod arrays were investigated. The results show that the morphology of t-NdV04 nanocrystals is greatly related to the pH value of precursor solution and that strong basic solution is not in favor of the formation of t-NdVO_4 nanoparticles. Due to the strong adhesive action and stabilization of OH^-ions to some crystal faces of NdVO_4, neodymium vanadate crystallite grows into oriented short nanorods and then into nanorod arrays. The shape, crystalline and dimension of NdVO_4 nanocrystals can be effectively governed in our work.

Hydrothermal synthesis and optical properties of Zn_(1-x)Mn_xS nanorods

Zn1-xMnxS （x = 0-0.05） nanorods were successfully synthesized through a hydrothermal route. The morphology, composition and microstructure of Zn1-xMnxS nanorods were characterized respectively by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and Raman spectrometer. The optical properties of Zn1-xMnxS nanorods were determineded by UV-Vis absorption spectroscopy and photo- luminescence （PL） emission spectroscopy. The results show that the introduction of Mn^2＋ on interstitial sites in ZnS lattice has significant influence on the Raman spectra, UV-Vis absorption spectra and PL emis- sion spectra. With the increase of Mn^2＋, the lengths of the sampled nanorods become shorter and the morphologies of the products show disorder accompanied by some nanoparticles. The absorption band edge shifts to longer wavelength. The intensity of the ZnS-related emission gradually becomes weaker, whereas, the Mn^2＋-related broad emission spectra located at 580 nm gradually red-shifts and increases. Occupation of Zn^2＋ sites in the lattice by Mn^2＋ ions results in lattice distortion and influences the energy level structure of ZnS. The Mn doping is found responsible for the changes in the defect-related emission of the ZnS nanorods.