Potential of adjuvants to reduce drift in agricultural spraying

The reduction of pesticide spraying drift is still one of the major challenges in Brazilian agriculture. The aim of this study was to evaluate the potential of different adjuvant products, such as surfactants, drift retardants, mineral oil and vegetable oil for reducing drift in agricultural spraying. The experiment consisted of quantifying drift of sprayings of 18 adjuvants dissolved in water under controlled conditions in a wind tunnel. Tests were performed in triplicates with spraying nozzles type Teejet XR8003 VK, pressure of 200kPa and medium drops. Solutions sprayed were marked with Brilliant Blue dye at 0.6% (m v-1). The drift was collected using polyethylene strips transversally fixed along the tunnel at different distances from the nozzle and different heights from the bottom part of the tunnel. Drift deposits were evaluated by spectrophotometry in order to quantify deposits. The adjuvants from chemical groups of mineral oil and drift retardant resulted in lower values of drift in comparison with surfactants and water. The results obtained in laboratory show that the selection of appropriate class and concentration of adjuvants can significantly decrease the risk of drift in agricultural spraying. However, the best results obtained in laboratory should be validated with pesticide under field conditions in the future.

Effect of adjuvants on the amount of air included in droplets generated by spray nozzles

The air included in droplets generated by spray nozzles directly int0erferes in transport, deposition and retention of the droplets after its impact on the target. The objective of this study was to analyze the interference of adjuvants in the amount of air included in droplets generated by spray nozzles. The treatments were composed by four spray solutions containing mineral oil, vegetable oil, surfactant and water, and three spray nozzles, two air induction type and one pre-orifice. The air included was calculated by the difference between the volume of spray mix (air plus liquid) and only the liquid, which was made by means of sprayed samples captured in a funnel and collected in a graduated cylinder. The surface tension was estimated by the gravimetric method using a precision scale and a graduated pipette. The surfactant provided the largest percentage of air included in the spray. For the surface tension, the mineral oil and the surfactant had the lowest values. It was concluded that the use of adjuvants had a direct influence on the percentage of air included. In addition, products with greater ability to reduce surface tension and to form homogeneous solutions provided the increase in the percentage of air included in the droplet.

Microencapsulation of pequi pulp by spray drying: use of modified starches as encapsulating agent

The aim of this study was to evaluate the microencapsulation of pequi pulp by spray drying. A central composite rotational design was used in order to evaluate the effect of the independent variables: inlet air temperature, surfactant concentration and modified starch concentration. The dependent variables were assumed as yield of the process and the product features microencapsulated. A selection of the best process condition was performed to obtain the best condition of a product with the highest vitamin C and carotenoids content. Powders showed moisture content below 2%. The experimental values of hygroscopicity, yield, water activity, total carotenoids and vitamin C powders ranged from 7.96 to 10.67 g of adsorbed water/100g of solids, 24.34 to 49.80%, 0.13 to 0.30, 145.78 to 292.11 mg of ascorbic acid/g of pequi solids and 15.51 to 123.42 mg of carotenoids/g of pequi solids, respectively. The inlet air temperature 140°C, the surfactant concentration of 2.5% and the modified starch concentration of 22.5% was recommended as the selected condition. By the scanning electron microscopy, it was observed that most of the particles had spherical shape and smooth surface.

SPRAY DEPOSITION AT TWO GROWTH STAGES OF CATTAIL

ABSTRACT Surfactant use in spray solutions has a major advantage of reducing droplet surface tension and increasing deposition. We aimed to evaluate droplet deposition on cattail plants (Typha subulata) using food coloring (Brilliant Blue - FD & C-1) as marker added to spray solution at two different growth stages: vegetative (4 leaves) and flowering (5 leaves). The treatments were arranged in a completely randomized design with four replications and five plants per plot (16.2-L tanks). Treatments consisted of adding into spray solutions Brilliant Blue alone (control), Brilliant Blue + 0.5% v/v Aterbane and Brilliant Blue + 0.01% v/v Silwet. Spraying was performed by a pressurized CO2 sprayer at 220 kPa using two Teejet XR 8002 nozzles at a spray volume of 200 L ha-1. We observed that surfactant addition provided uniform deposition of spray solution on T. subulata plants at both growth stages compared to treatments without surfactant. However, this product has not increased spray deposits on cattail leaves at both stages.

Sarcoma sinovial primário do esôfago

Synovial sarcomas are uncommon malignant mesenchymal tumors occurring mainly near the joints of the extremities of young adults. Synovial sarcomas are exceedingly rare neoplasms of the digestive tract. We report the first diagnosed case of esophageal synovial sarcoma, highlighting its diagnostic features surgical management and follow-up.

Improving diquat efficacy on grasses by adding adjuvants to the spray solution before use

The effect of five adjuvants (non-ionic surfactant, paraffinic oil, vegetable oil, mixture of fatty acids methyl esters plus surfactant blend, and organosilicone) on diquat efficacy was assessed on poverty brome, sterile oat, and Italian ryegrass in field and pot experiments. All tank mixtures with diquat increased diquat efficacy from 50-54% to 77-98% as for fresh weight reduction, indicating significant enhancement of diquat efficacy on grasses. The increased efficacy was most likely attributed to better droplet retention and diffusion on the leaf surfaces. When combined with non-ionic surfactant, diquat showed slightly more rapid control of grass weeds (i.e. symptoms were visible within a few hours after application).

Glyphosate Effectiveness in the Control of Macrophytes Under a Greenhouse Condition

The aim of this study was to assess the effectiveness of glyphosate, as Rodeo(r) formulation, to control Eichhornia crassipes, Pistia stratiotes, Salvinia molesta, Salvinia herzogii and Urochloa subquadripara, under greenhouse conditions. The doses assessed were (480, 960, 1440, 1920, 2400, 2880, 3360 and 3840 g ha-1 of glyphosate) with 0.5% of the Aterbane(r) BR surfactant and a control, with no herbicide application. All experiments were conducted in a completely randomized experimental design with ten replications. Applications were carried out by precision backpack sprayer at a CO2 constant pressure of 25 psi and spray solution consumption of 200 L ha-1. Product effectiveness was determined by assessing the growth inhibitions and phytotoxicity signals during the periods of 3, 7, 15, 21, 30 and 45 days after application (DAA). At 45 DAA, the highest glyphosate dose (3840 g ha-1) displayed 100% effectiveness for all four macrophyte species. Under greenhouse conditions, the glyphosate in formulation Rodeo(r) with 0.5% of Aterbarne(r) BR surfactant showed excellent effectiveness, inhibiting the growth of the floating aquatic macrophytes. This procedure can be included on the tillage plans for these species.

Effect of urea on biomimetic aggregates

The effect of urea on biomimetic aggregates (aqueous and reversed micelles, vesicles and monolayers) was investigated to obtain insights into the effect of the denaturant on structured macromolecules. Direct evidence obtained from light scattering (static and dynamic), monolayer maximum isothermal compression and ionic conductivity measurements, together with indirect evidence from fluorescence photodissociation, fluorescence suppression, and thermal reactions, strongly indicates the direct interaction mechanism of urea with the aggregates. Preferential solvation of the surfactant headgroups by urea results in an increase in the monomer dissociation degree (when applied), which leads to an increase in the area per headgroup and also in the loss of counterion affinities

A role for angiogenesis in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic debilitating disease characterized by distinct autoimmune, inflammatory and fibrovascular components which lead to synovial proliferation and joint destruction. However, existing treatments specifically target only autoimmune and inflammatory components despite the fact that neovascularization of the inflamed synovium is a hallmark of rheumatoid arthritis. Angiogenesis may contribute to synovial growth, leukocyte recruitment and tissue remodeling, thus potentiating disease progression. Although no therapies currently target angiogenesis, several existing therapies have anti-angiogenic activity. Recent advances in anti-angiogenic strategies in oncology, including the identification of integrin avß3 as a crucial effector of angiogenesis, suggest a means to assess the role of angiogenesis in rheumatoid arthritis. Synovial endothelial cells have been shown to express integrin avß3, suggesting that these cells may be targeted for angiogenesis inhibition. Prior studies in rat arthritis models have shown benefit after the addition of broad spectrum integrin antagonists. However, formal assessment of integrin-targeted anti-angiogenic activity is now underway. These controlled studies will be important in assessing the efficacy of therapies which target angiogenesis in RA.

Morphologic and biochemical changes in male rat lung after surgical and pharmacological castration

The morphology of the rat lung was studied by light microscopy in different situations: after surgical and pharmacological castration and after administration of testosterone to the castrated rat to determine if the androgen is required to maintain the normal morphology of the lung. We also determined the effect of flutamide on the phospholipid composition of both the surfactant and microsomes of the lung. Rats were separated into five groups: I - control non-castrated rats, II - castrated rats sacrificed 21 days after castration, III - castrated rats that received testosterone daily from day 2 to day 21 after castration, IV - castrated rats that received testosterone from day 15 to day 21 after castration, and V - control rats injected with flutamide for 7 days. The amount of different phospholipids in the surfactant and microsomes of the lung was measured in group I and V rats. At the light microscopy level, the surgical and pharmacological castration provoked alterations in the morphology of the lung, similar to that observed in human lung emphysema. The compositions of surfactant and microsomes of the lung were similar to those previously reported by us for the surgically castrated rats. These results indicate that androgens are necessary for the normal morphology as well as for some metabolic aspects of the lung.

DNA-lipid systems: A physical chemistry study

It is well known that the interaction of polyelectrolytes with oppositely charged surfactants leads to an associative phase separation; however, the phase behavior of DNA and oppositely charged surfactants is more strongly associative than observed in other systems. A precipitate is formed with very low amounts of surfactant and DNA. DNA compaction is a general phenomenon in the presence of multivalent ions and positively charged surfaces; because of the high charge density there are strong attractive ion correlation effects. Techniques like phase diagram determinations, fluorescence microscopy, and ellipsometry were used to study these systems. The interaction between DNA and catanionic mixtures (i.e., mixtures of cationic and anionic surfactants) was also investigated. We observed that DNA compacts and adsorbs onto the surface of positively charged vesicles, and that the addition of an anionic surfactant can release DNA back into solution from a compact globular complex between DNA and the cationic surfactant. Finally, DNA interactions with polycations, chitosans with different chain lengths, were studied by fluorescence microscopy, in vivo transfection assays and cryogenic transmission electron microscopy. The general conclusion is that a chitosan effective in promoting compaction is also efficient in transfection.

Antinociceptive effects of Cremophor EL orally administered to mice

Surfactants are frequently used to improve solubilization of lipophilic drugs. Cremophor EL (CrEL) is a polyoxyethylated castor oil surfactant used to solubilize water-insoluble drugs such as anesthetic, antineoplastic, immunosuppressive and analgesic drugs, vitamins and new synthetic compounds, including potential analgesics. The antinociceptive effect of CrEL (3.2, 6.4 and 10.6 g/kg, in 10 ml/kg body weight, by gavage) on the abdominal writhing response induced by intraperitoneal administration of acetic acid (0.8%, 10 ml/kg body weight) and on the tail immersion test was investigated in mice. Control animals received castor oil (10 ml/kg body weight) or saline (0.9% NaCl, 10 ml/kg body weight). CrEL reduced nociception in a dose-dependent manner in both tests. At 10.6 g/kg, CrEL caused antinociception similar to that induced by dipyrone (300 mg/kg, by gavage) in the abdominal writhing test, and antinociception similar to that induced by morphine (20 mg/kg, by gavage) in the tail immersion test. The effect of castor oil was similar to that of saline in both assays. These data indicate that the appropriate controls should be used when evaluating the effects of potential antinociceptive agents dissolved in CrEL.

RANK, RANKL and osteoprotegerin in arthritic bone loss

Rheumatoid arthritis is characterized by the presence of inflammatory synovitis and destruction of joint cartilage and bone. Tissue proteinases released by synovia, chondrocytes and pannus can cause cartilage destruction and cytokine-activated osteoclasts have been implicated in bone erosions. Rheumatoid arthritis synovial tissues produce a variety of cytokines and growth factors that induce monocyte differentiation to osteoclasts and their proliferation, activation and longer survival in tissues. More recently, a major role in bone erosion has been attributed to the receptor activator of nuclear factor kappa B ligand (RANKL) released by activated lymphocytes and osteoblasts. In fact, osteoclasts are markedly activated after RANKL binding to the cognate RANK expressed on the surface of these cells. RANKL expression can be upregulated by bone-resorbing factors such as glucocorticoids, vitamin D3, interleukin 1 (IL-1), IL-6, IL-11, IL-17, tumor necrosis factor-alpha, prostaglandin E2, or parathyroid hormone-related peptide. Supporting this idea, inhibition of RANKL by osteoprotegerin, a natural soluble RANKL receptor, prevents bone loss in experimental models. Tumor growth factor-ß released from bone during active bone resorption has been suggested as one feedback mechanism for upregulating osteoprotegerin and estrogen can increase its production on osteoblasts. Modulation of these systems provides the opportunity to inhibit bone loss and deformity in chronic arthritis.

Effect of the human leukocyte antigen HLA-DRB1 and anti-cyclic citrullinated peptide on the outcome of rheumatoid arthritis patients

Our objective was to determine whether the presence of the human leukocyte antigen HLA-DRB1 locus is associated with production of anti-cyclic citrullinated peptide antibodies (anti-CCP Abs) and to what extent they are associated with increased susceptibility to and severity of rheumatoid arthritis (RA) in Egyptian patients. Twenty-nine RA patients gave informed consent to participate in a case-control study that was approved by the Ain Shams University Medical Ethics Committee. RA disease activity and severity were determined using the simplified disease activity index and Larsen scores, respectively. We used a wide scale national study on the pattern of HLA typing in normal Egyptians as a control study. Anti-CCP Abs and HLA-DRB1 typing were determined for all subjects. The alleles most strongly associated with RA were HLA-DRB1 [*01 , *04 and *06] (41.4%). RA patients with serum anti-CCP Ab titers above 60 U/mL had a significantly higher frequency of HLA-DRB1*01 (58.3%) and HLA-DRB1*04 alleles (83.3%). Significant positive correlations were found between serum and synovial anti-CCP Ab titer, RA disease activity, and severity (r = 0.87, 0.66 and 0.63, respectively; P < 0.05). HLA-DRB1 SE+ alleles [*01 and *04] were highly expressed among Egyptian RA patients. The presence of these alleles was associated with higher anti-CCP Ab titer, active and severe RA disease. Early determination of HLA-DRB1 SE+ alleles and serum anti-CCP Ab could facilitate the prediction of the clinical course and prognosis of RA when first evaluated leading to better disease control.

Expression of MMP-2 and MMP-9 in the rat trigeminal ganglion during the development of temporomandibular joint inflammation

Orofacial pain is a prevalent symptom in modern society. Some musculoskeletal orofacial pain is caused by temporomandibular disorders (TMDs). This condition has a multi-factorial etiology, including emotional factors and alteration of the masticator muscle and temporomandibular joints (TMJs). TMJ inflammation is considered to be a cause of pain in patients with TMD. Extracellular proteolytic enzymes, specifically the matrix metalloproteinases (MMPs), have been shown to modulate inflammation and pain. The purpose of this investigation was to determine whether the expression and level of gelatinolytic activity of MMP-2 and MMP-9 in the trigeminal ganglion are altered during different stages of temporomandibular inflammation, as determined by gelatin zymography. This study also evaluated whether mechanical allodynia and orofacial hyperalgesia, induced by the injection of complete Freund's adjuvant into the TMJ capsule, were altered by an MMP inhibitor (doxycycline, DOX). TMJ inflammation was measured by plasma extravasation in the periarticular tissue (Evans blue test) and infiltration of polymorphonuclear neutrophils into the synovial fluid (myeloperoxidase enzyme quantification). MMP expression in the trigeminal ganglion was shown to vary during the phases of the inflammatory process. MMP-9 regulated the early phase and MMP-2 participated in the late phase of this process. Furthermore, increases in plasma extravasation in periarticular tissue and myeloperoxidase activity in the joint tissue, which occurred throughout the inflammation process, were diminished by treatment with DOX, a nonspecific MMP inhibitor. Additionally, the increases of mechanical allodynia and orofacial hyperalgesia were attenuated by the same treatment.