美国特殊农药市场机会

1前言在美国,特殊农药(special pesticide或specialty)又称非农用化学品(non-agrochemi-cal或Non Ag),主要包括家居和花园护理产品、草坪专用护理产品、害物专用护理产品、公共卫生产品、杀鼠剂、园艺及花卉产品。众所周知,美国化学农药登记费用高,费时长,所以很多中国企业不敢     

The effect of three different doses of sodium pentosan polysulphate on haematological and haemostatic variables in adult horses

OBJECTIVE: To evaluate the effects of three different doses of sodium pentosan polysulphate (PPS) on haematological and haemostatic variables in adult horses. DESIGN: Eight adult standardbred horses were used. All horses received a single injection of 0, 3, 6, and 10 mg/kg of PPS at the beginning of each treatment week for 4 weeks so that by the end of the study all horses had received all four doses of PPS. Blood samples were collected at 0, 1, 2, 3, 4, 6, 8, 12, 24, 48, and 168 h after each weekly injection of PPS. Variables measured were packed cell volume, haemoglobin, red blood cell count, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, platelet count, white cell count, neutrophil count, lymphocyte count, eosinophil count, monocyte count, serum protein, fibrinogen, prothrombin time, and activated partial thromboplastin time (PTT). Data were analysed using an ANOVA. Significance was set at P < 0.05. RESULTS: There was a dose-dependent increase in PTT. A significant increase in PTT occurrred in all treatment groups when compared to horses receiving 0 mg/kg in which there was no change over time. The PTT values all returned to baseline by 48 h after treatment. The mean neutrophil count was higher 3 h after treatment when compared to time 0. Horses receiving 3 mg/kg of PPS had a higher lymphocyte count 4 h after injection, and those receiving 6 and 10 mg/kg had higher counts at 3,4,6 and 8 h after injection when compared to time 0. At 8 h after injection horses receiving 6 and 10 mg PPS had higher lymphocyte counts than horses not receiving PPS. CONCLUSIONS: PPS causes a dose-dependent prolongation of PTT in horses. At the dose rates currently recommended for treatment of joint problems in horses this increase was small and remained elevated from baseline for up to 24 h. Based on these findings doses of PPS up to 3 mg/kg should not be administered to horses within 24 h of high stress activities or where physical injury may occur.     

ENDOSCOPIC ULTRASONOGRAPHY FOR THE DIAGNOSIS OF INTRATHORACIC LESIONS IN TWO DOGS

Endoscopic ultrasound was developed initially in humans to overcome limitations of conventional ultrasound in examining certain internal organs due to intervening bone or air-filled structures. Endoscopic ultrasound has been used most widely in investigation of the gastrointestinal tract in humans, but many intrathoracic applications as well as endoscopic ultrasound-guided techniques have recently been described. Mediastinal and pulmonary structures can be examined with endoscopic ultrasound since a high frequency ultrasound probe can be brought into close contact with the areas of interest via a transesophageal approach. The purpose of this report is to describe the application of endoscopic ultrasound as an aid in the diagnosis of intrathoracic disease in the dog. Two dogs, one with a history of prior esophageal foreign body extraction, the other with apathy, weakness and dyspnea were referred for further investigation. Both dogs had caudal intrathoracic soft tissue opacities diagnosed radiographically, but their origin and nature were difficult to determine. Conventional ultrasound was limiting in both dogs due to their location and superimposition of gas-filled structures. With endosonography lesions were characterized more completely. We have found endoscopic ultrasound to be an elegant diagnostic tool for the investigation of radiographically detected intrathoracic lesions in the dog whose origins are difficult to determine or do not lend themselves to investigation by conventional ultrasound. Endoscopic ultrasound provides valuable diagnostic information complementary to that provided radiographically which aids in therapeutic planning. Endoscopic ultrasound was also more sensitive for detecting mediastinal lymphadenomegaly than radiography in one of the dogs. An additional advantage of endoscopic ultrasound is the fact that US-guided tissue sampling can be performed during the examination.     

Trace element concentrations in fish from three Adirondack lakes with different pH values

Concentrations of 29 elements were detected in the axial muscle, and 44 elements were detected in the gut contents of white suckers (Catostomus commersoni) and yellow perch (Perca favescens) from three lakes located in the New York State Adirondack Preserve. The study lakes were acidic Darts Lake, variable pH Lake Rondaxe, and circumneutral Moss Lake. For the majority of the elements, there were no clear differences in the muscle concentrations among fish inhabiting the three types of lakes. Two notable exceptions were Hg and Pb. With some exceptions, the highest muscle tissue Pb concentrations were found in fish from the acidic lake. For both species, the Hg was higher in the muscle than in the gut regardless of lake acidity. Other elements potentially toxic to humans (As, Cd, Ga, Pb, Se, and TI) were not accumulated in the muscle relative to the gut.     

Forest clearcutting effects on trace metal concentrations: Spatial patterns in soil solutions and streams

Increased concentrations of solutes in drainage waters following forest clearcutting may affect downstream water quality. The objective of this study was to evaluate some of the processes regulating concentrations of trace metals and Fe in soil solutions and streamwater in a clearcut watershed by determining changes in metal release by soil horizon, stand vegetation and elevation. Commercial whole-tree harvesting of a watershed at the Hubbard Brook Experimental Forest, NH, U.S.A. resulted in increased loss of NO _inf3 ^sup? from the study watershed. This N0 _inf3 ^sup? loss resulted in acidification of soil solutions, which was associated with release of Mn and Zn from mineral soil to soil solutions and streamwater. Significant correlations of Pb and Fe with dissolved organic C (DOC) suggested that mobilization of these metals was linked to DOC transfer. However, there was little evidence of increased release of DOC, Fe, or Pb following the whole-tree harvest, except in a high elevation spruce-fir zone with shallow soils.     

Laboratory investigations of the deposition of oxidation products of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) to aqueous solutions

Laboratory experiments were conducted to investigate the deposition to aqueous media of the gas phase oxidation products of the following hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs): HCFC-22 (CClF₂H), HFC-41 (CH₃F), HCFC-123 (CCl₂HCF₃), HCFC-124 (CClFHCF₃), HFC-125 (CF₃CF₂H), HFC-134a (CF₃CFH₂), HCFC-141b (CCl₂FCH₃), HCFC-142b (CClF₂CH₃), and HFC-152a (CF₂HCH₃). Single component experiments were conducted were the oxidation products CF₃CFO, COF₂, CF₃C(O)Cl were exposed under laminar flow conditions to alkaline, acidic, and neutral solutions in a aluminum exposure trough. The anionic composition of the exposure solutions were used to determine the effective deposition velocity. Exposures to neutral solutions were also conducted for irradiated HFC and HCFC/Cl₂/air mixtures. The combined single component and irradiated mixture experiments were used to measure the effective deposition velocities of C(O)F₂, C(O)FCl, HFC(O), CF(O)OOCF(O), CF₃CCl(O), CF₃CF(O). The deposition velocities differed by as much as a factor of two with the largest velocities found for C(O)F₂ and CF₃CF(O). The data were insufficient to determine the extent to which gas and liquid phase resistance controlled the overall deposition. However, the data were used to estimate lower limits for the laboratory aqueous resistance and the results were found to be consistent with the recent conclusions of Wine and Chameides who reported the deposition of the oxidation products to oceans and cloudwater was sufficiently fast that there was little likelihood that the products would be transported to the stratosphere.     

Seasonal and long-term temporal patterns in the chemistry of Adirondack lakes

There is considerable interest in the recovery of surface waters from acidification by acidic deposition. The Adirondack Long-Term Monitoring (ALTM) program was established in 1982 to evaluate changes in the chemistry of 17 Adirondack lakes. The ALTM lakes exhibited relatively uniform concentrations of SO₄ ^2?. Lake-to-lake variability in acid neutralizing capacity (ANC) was largely due to differences in the supply of basic cations (Ca²⁺, Mg²⁺, K⁺, Na⁺; C_B) to drainage waters. Lakes in the western and southern Adirondacks showed elevated concentrations of NO₃ ^?, while lakes in the central and eastern Adirondacks had lower NO₃ ^? concentrations during both peak and base flow periods. The ALTM lakes exhibited seasonal variations in ANC. Lake ANC was maximum during the late summer or autumn, and lowest during spring snowmelt. In general Adirondack lakes with ANC near 100 Μeq L^?1 during base flow periods may experience decreases in ANC to near or below 0 Μeq L^?1 during high flow periods. The ALTM lakes have exhibited long-term temporal trends in water chemistry. Most lakes have demonstrated declining SO₄ ^2?, consistent with decreases in SO₂ emissions and SO₄ ^2? in precipitation in the eastern U.S. Reductions in SO₄ ^2? have not coincided with a recovery in ANC. Rather, ANC values have declined in some ALTM lakes. This pattern is most likely due to increasing concentrations of NO₃ ^? that occurred in most of the ALTM drainage lakes.     

A chloride budget for Onondaga Lake,New York,U.S.A.

A Cl budget is presented for a 12 yr period (1970–1981) for Cl enriched (approximate volume-weighted average concentration of 1500 mg Cl L^?1) Onondaga Lake, New York. The budget utilizes continuous discharge and lake and stream water chemistry data, collected at an interval of approximately 2 weeks, over the 12 yr study period. Budget calculations are supplemented by high frequency water chemistry data from the lake and the tributary carrying the major portion of the loading. More than 85% of the external load of Cl (approximately 9 × 10⁸ kg yr^?1) to the lake originates from an alkali manufacturer. Export of Cl from the lake was highly correlated to outflow from the lake (R = 0.915, for a resolution of 1 mo). A good balance between estimated external loads and lake export was obtained (within 7%) for the 12 yr period, indicating that lake concentrations are consistent with external loading of this conservative substance. The results of this analysis contradict previous calculations that indicated 40 to 50% of the Cl in the lake originated from natural internal sources.     

REVIEW OF DIAGNOSTIC IMAGING OF EAR DISEASES IN THE DOG AND CAT

Diagnostic imaging techniques (conventional radiography, computed tomography and magnetic resonance imaging) are an essential tool in the diagnostic work-up of ear diseases. Conventional radiography is commonly used, but often lacks sensitivity. Computed tomography (CT) and magnetic resonance (MR) are complementary imaging studies of the middle ear, labyrinth, internal auditory canal and their contents. CT provides excellent images of bony structures and is indicated where osseous changes are of greatest diagnostic importance. MR is superior in imaging soft tissue components including intralabyrinthine fluid. Therefore, more than one of these imaging techniques may be required in order to make a diagnosis.