Chitosan-Genipin Microspheres for the Controlled Release of Drugs: Clarithromycin,Tramadol and Heparin     

Ruth Harris  Elena Lecumberri  Angeles Heras 《Marine drugs》2010,8(6):1750-1762

The aim of this study was to first evaluate whether the chitosan hydrochloride-genipin crosslinking reaction is influenced by factors such as time, and polymer/genipin concentration, and second, to develop crosslinked drug loaded microspheres to improve the control over drug release. Once the crosslinking process was characterized as a function of the factors mentioned above, drug loaded hydrochloride chitosan microspheres with different degrees of crosslinking were obtained. Microspheres were characterized in terms of size, morphology, drug content, surface charge and capacity to control in vitro drug release. Clarithromycin, tramadol hydrochloride, and low molecular weight heparin (LMWH) were used as model drugs. The obtained particles were spherical, positively charged, with a diameter of 1–10 μm. X-Ray diffraction showed that there was an interaction of genipin and each drug with chitosan in the microspheres. In relation to the release profiles, a higher degree of crosslinking led to more control of drug release in the case of clarithromycin and tramadol. For these drugs, optimal release profiles were obtained for microspheres crosslinked with 1 mM genipin at 50 ºC for 5 h and with 5 mM genipin at 50 ºC for 5 h, respectively. In LMWH microspheres, the best release profile corresponded to 0.5 mM genipin, 50 ºC, 5 h. In conclusion, genipin showed to be eligible as a chemical-crosslinking agent delaying the outflow of drugs from the microspheres. However, more studies in vitro and in vivo must be carried out to determine adequate crosslinking conditions for different drugs.  相似文献   

Occurrence, Distribution and Epidemiology of Grapevine Yellows in Spain     

Assumpció Batlle  M. Angeles Martínez  Amparo Laviña 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(9):811-816

The main viticultural production areas in Spain were surveyed in 1994, 1995 and 1996 for the occurrence and incidence of Grapevine Yellows diseases associated to phytoplasmas. Samples from 300 plants showing symptoms of phytoplasma infection were collected from grapevine fields in the Spanish regions of Aragón, Catalonia and Navarra and analysed by PCR with specific primers for a non-ribosomal DNA of stolbur/Bois Noir (BN) and of Flavescence dorée (FD) phytoplasma. Nested PCR with universal primers P1/P7 and fU5/rU3 was also used. In the survey conducted in 1994 and 1995 only BN/stolbur phytoplasma was detected. The incidence of symptomatic plants was low in five plots of Catalonia from 3% to 18% in 1994 and 1995, respectively, and high in two plots of Navarra, from 60% to 80%. In the survey conducted in 1996 the incidence of symptomatic plants in Catalonia increased (6–80%) due to the presence of FD in five plots in the Northeastern Catalonia. An epidemiological study was carried out in two BN-affected plots of two regions from 1994 to 1997, with the evaluation of potential vectors and of host plants. The stolbur phytoplasma was found in individuals from different insect species belonging to the families Cicadellidae and Delphacidae. Some wild plants naturally infected with stolbur phytoplasma around the infected grapevines were: Convolvulus arvensis, Lavandula officinalis, Polygonum convolvulus, Solanum nigrum, and Thymus officinalis. The incidence of the disease in one BN-infected grapevine plot increased from 3.4% in 1994 to 18.40% in 1997.  相似文献   

The significance of a major outbreak of quarantinable disease to the Australian horse industries     

RF CLEMENT  KA DOYLE  JG MURRAY 《Australian veterinary journal》1990,67(2):77-78

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Protective effect of cobalt against apparent liver damage in sheep exposed to toxic annual ryegrass     

SC DAVIES  IH WILLIAMS  CL WHITE  JG ALLEN  JA EDGAR  PA COCKRUM  P. STEWART 《Australian veterinary journal》1993,70(5):186-187

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Government Animal Health Laboratory Services in Western Australia   总被引：1，自引：1，他引：0  

RB RICHARDS  TM ELLIS  JG ALLEN 《Australian veterinary journal》1993,70(9):321-323

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Effect of new ethyl and methyl carbamates on biological parameters and reproduction of the cattle tick Rhipicephalus microplus     

M.G. Prado-Ochoa  M.A. Muñoz-Guzmán  V.H. Abrego-Reyes  A.M. Velázquez-Sánchez  M. Lara-Rocha  C. Cuenca-Verde  E. Angeles  F. Alba-Hurtado 《Veterinary parasitology》2013

The effect of carbamates on engorged female Rhipicephalus microplus ticks and larvae was evaluated using the adult immersion test (AIT) and the larval packet test (LPT), respectively. Seventeen synthetic carbamates different from current commercial acaricides were synthesised at the National Autonomous University of Mexico. None of the carbamates had an effect on the percentage of females laying eggs. Six of the compounds inhibited egg laying up to 65.4% and inhibited egg hatching by up to 100% (p < 0.05). Compared to untreated females, eggs produced by treated females had a dark, dry, opaque appearance and were less adherent. Carbamates LQM 934 and LQM 938 had an effect on larval mortality (p < 0.05). Carbamate LQM 934 showed lethal concentrations (LC) of LC₉₀ = 0.76% and LC₉₉ = 0.87%, while LQM 938 showed concentrations of LC₉₀ = 0.267% and LC₉₉ = 0.305%. The compounds were distributed into three classes of acaricidal activity using the AIT or the LPT. These three classes were as follows: (1) compounds having no apparent effect; (2) compounds that inhibit egg laying and embryo development or (3) compounds that exhibit acaricidal activity to larval ticks.  相似文献   

Successful rehabilitation and release of a powerful owl chick with suspected rodenticide poisoning     

R Cooke  N Carter  J Groves  N Scarfe  P Mason  JG White 《Australian veterinary journal》2023,101(11):453-459

The successful rehabilitation and release of raptor chicks can be challenging, especially when the chicks are still in the post-fledging dependency period. Here, we report on a recently fledged powerful owl chick that was held in care for 33 days before being successfully reunited with its parents. We document the steps undertaken during the entire process from collection from the wild to post-release monitoring and recommend clinical procedures for treatment of raptors entering veterinary facilities. Success of this rehabilitation was facilitated by early care and treatment for potential rodenticide poisoning, as well as the integration of citizen scientists monitoring the family unit in the field while the chick was in care and during the post-release period. Given the emerging evidence of widespread rodenticide poisoning in raptors both in Australia and globally, it is critical to suspect all raptors may have been exposed to anticoagulant rodenticides and commence treatment with vitamin K immediately. Routine treatment for rodenticides early increases the probability of successful recovery post-trauma as well as reducing the time in treatment as much as possible.  相似文献   

Stand structure, competition and growth of Scots pine (Pinus sylvestris L.) in a Mediterranean mountainous environment     

Antonio García-Abril  Susana Martin-Fernández  M. Angeles Grande  Jose A. Manzanera 《Annals of Forest Science》2007,64(8):825-830

The relationship between competition and tree growth was studied in four stands of Pinus sylvestris L. occurring in a continental Mediterranean mountain area (in the Guadarrama range, Spain), i.e., an uneven-aged stand, a stand with oak (Quercus pyrenaica Willd.) understorey, a plantation, and a mature even-aged stand. Competition was measured by a simple size-ratio distance-independent index and was negatively associated with tree diameter. This negative association was stronger in the uneven-aged, plantation and mature even-aged stands than in the stand with oak understorey. Competition was also negatively associated with current diameter increment. This relationship was moderately strong in the mature even-aged stand and weak in the uneven-aged stand and the plantation. In the uneven-aged and the mature even-aged stands, a weakly significant relationship was found between diameter growth and tree size, whereas these parameters were not associated in the stand with oak understorey. The competition index provided a better prediction of growth rate than the alternative use of diameter. Both diameter and basal area growth were greater in the uneven-aged than in the even-aged stands.  相似文献   

Effects of Biochar and Marble mud on Mine Waste Properties to Reclaim Tailing Ponds     

Maria Angeles Muoz  Jose German Guzman  Raul Zornoza  Fabian Moreno  Angel Faz  Rattan Lal 《Land Degradation \u0026amp; Development》2016,27(4):1227-1235

The effects of biochar addition in improving soil physical properties are not clearly understood in mining tailings. The objective of this study was to determine the effects of three different types of biochars, in addition to marble mud (MM) and their mixtures, on the structural stability and water retention of mine wastes in Cartagena, Spain. Biochars were produced at 500 °C from pig manure (PM), cotton (Gossipium hirsutum L.) crop residues (CR) and municipal solid waste (MSW). Biochars were added to the mine waste (MW) along with MM and a control (no amendments added). These mixtures were incubated in cores for 90 days (25 °C). PM and CR mixed with MM decreased soil bulk density (from 0 · 98 g cm^‐3 to 0 · 89 and 0 · 84 g cm⁻³, respectively). Amendments had no significant effect on total porosity whereas they increased gas diffusion by 100%, except for MSW. MM improved the plant available water from 0 · 59 to 2 · 56 cm as its combination with biochars, extremely relevant in water scarce climates. The micropores were likely replaced by mesopores when application of PM, CR, MM, and biochars + MM and they improved water retention. Total carbon (TC) and total nitrogen (TN) increased by using biochars and MM and no significant effects were assessed on aggregates. In general, MM mixed with PM and CR derived biochar improved the structural stability and exhibited a strong impact in reclaiming physical quality on mine tailings. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Anaerobic digestion of wastewater derived from the pressing of orange peel generated in orange juice production     

Siles JA  de Los Angeles Martín M  Martín A  Raposo F  Borja R 《Journal of agricultural and food chemistry》2007,55(5):1905-1914

A study of the anaerobic digestion of wastewater from the pressing of orange peel generated in orange juice production was carried out in a laboratory-scale completely stirred tank reactor at mesophilic temperature (37 degrees C). Prior to anaerobic treatment the raw wastewater was subjected to physicochemical treatment using aluminum sulfate as a flocculant and to pH reduction using a solution of sulfuric acid. The reactor was batch fed at COD loads of 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 g of COD. The process was very stable for all of the loads studied, with mean pH and alkalinity values of 7.5 and 3220 mg of CaCO3/L, respectively. The anaerobic digestion of this substrate was found to follow a first-order kinetic model, from which the specific rate constants for methane production, K(G), were determined. The K(G) values decreased considerably from 0.0672 to 0.0078 L/(g h) when the COD load increased from 1.5 to 5.0 g of COD, indicating an inhibition phenomenon in the system studied. The proposed model predicted the behavior of the reactor very accurately, showing deviations of <5% between the experimental and theoretical values of methane production. The methane yield coefficient was found to be 295 mL of CH4 STP/g of COD removed, whereas the mean biodegradability of the substrate (TOC) was 88.2%. A first-order kinetic model for substrate (TOC) consumption allowed determination of the specific rate constants for substrate uptake, K(C), which also decreased with increasing loading, confirming the above-mentioned inhibition process. Finally, the evolution of the individual volatile fatty acid concentrations (acetic, C2; propionic, C3; butyric, C4; isobutyric, iC4; valeric, C5; isovaleric, iC5; and caproic, C6) with digestion time for all loads used was also studied. The main acids generated were acetic and propionic for all loads studied, facilitating the conversion into methane.  相似文献