Thermodynamics of calcite growth: baseline for understanding biomineral formation     

HH Teng  PM Dove  CA Orme  De Yoreo JJ 《Science (New York, N.Y.)》1998,282(5389):724-727

The complexity of biomineralized structures suggests the potential of organic constituents for controlling energetic factors during crystal synthesis. Atomic force microscopy was used to investigate the thermodynamic controls on carbonate growth and to measure the dependence of step speed on step length and the dependence of critical step length on supersaturation in precisely controlled solutions. These data were used to test the classic Gibbs-Thomson relationship and provided the step edge free energies and free energy barriers to one-dimension nucleation for calcite. Addition of aspartic acid, a common component in biomineralizing systems, dramatically affected growth morphology and altered the magnitude of the surface energy.  相似文献   

Effects of lime application and test branch position on 14C-photosynthate partitioning in 3-year-old Sitka spruce (Picea sitchensis plants growing in pots containing peat soils     

Kakei  M; Clifford  PE 《Forestry》1999,72(3):223-235

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Tetraoxanes as a new class of efficient herbicides comparable with commercial products          下载免费PDF全文

Raphael C Cusati  Luiz CA Barbosa  Célia RA Maltha  Antônio J Demuner  Alberto Oliveros‐Bastidas  Antônio A Silva 《Pest management science》2015,71(7):1037-1048

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Natural products for pest control: an analysis of their role,value and future     

B Clifford Gerwick  Thomas C Sparks 《Pest management science》2014,70(8):1169-1185

Natural products (NPs) have long been used as pesticides and have broadly served as a source of inspiration for a great many commercial synthetic organic fungicides, herbicides and insecticides that are in the market today. In light of the continuing need for new tools to address an ever‐changing array of fungal, weed and insect pests, NPs continue to be a source of models and templates for the development of new pest control agents. Interestingly, an examination of the literature suggests that NP models exist for many of the pest control agents that were discovered by other means, suggesting that, had circumstances been different, these NPs could have served as inspiration for the discovery of a great many more of today's pest control agents. Here, an attempt is made to answer questions regarding the existence of an NP model for existing classes of pesticides and what is needed for the discovery of new NPs and NP models for pest control agents. © 2014 Society of Chemical Industry  相似文献   

Impact of 24-h Cooling Prior to Freezing on the Survival of Domestic Cat (Felis catus) Epididymal Sperm     

JLA Martins  AISB Villaverde  AFM Lima  PVM Steagall  JCP Ferreira  CA Taconeli  MD Lopes 《Reproduction in domestic animals》2009,44(S2):366-368

The aim of this study was to investigate the impact of a 24-h cooling period prior to freezing on domestic cat epididymal sperm viability. Fifteen tomcats were submitted to routine orchiectomy and sperm samples were retrieved from both epididymides in a Tris–glucose–20% egg yolk extender. For each tomcat, the diluted sperm was split into two equal volumes and cooled to 5°C at a rate of 0.5°C/min; one sample for 60 min (control) and the other for 24 h (cooled). After the cooling period, samples from both groups were frozen using an identical freezing protocol. Sperm samples were evaluated in three different periods: immediately after harvesting, after cooling at 5°C for 24 h (cooled group) and after freezing–thawing of control and cooled groups. Evaluations consisted of sperm motility and progressive status, sperm morphology and plasma membrane integrity (PMI) using two fluorescent probes. After cooling for 24 h, a decrease (p < 0.05) in sperm motility, progressive status and PMI was observed when compared to sperm samples immediately after collection. Comparing the results obtained after thawing, no difference (p < 0.05) was found regarding sperm motility, progressive status, PMI and sperm morphology between control and cooled groups. The results from the present study show that cooling cat epididymal spermatozoa at 5°C for 24 h prior to freezing does not lead to major damage of spermatozoa impairing the freeze–thaw process.  相似文献   

Are ovine fenugreek (Trigonella foenum‐graecum) staggers and kangaroo gait of lactating ewes two clinically and pathologically similar nervous disorders?   总被引：1，自引：1，他引：0  

CA Bourke 《Australian veterinary journal》2009,87(3):99-101

Fenugreek staggers has occurred in sheep in Victoria, as both an acute and a chronic syndrome. Signs included quadraparesis, a high stepping fore limb gait and a 'bunny-hopping' hind limb gait. Changes consistent with acute oedema were found in the brain and spinal cord of acute cases, and Wallerian degeneration in the peripheral nerves of chronic cases. Kangaroo gait occurred in ewes in New South Wales, and the clinical signs and microscopic changes were remarkably similar to those of fenugreek staggers. Although the diet associated with each is different the causal agent may be the same.  相似文献   

氧化应激与疾病     

Clifford A Adams  武书庚  齐广海  李海涛 《饲料与畜牧》2009,(3):10-12

饲料对动物的作用之一就是通过各组分的氧化提供代谢能,为在细胞线粒体中有效产生能量,每种动物均需要氧气。但氧是一种诱变气体,具有毒性,细胞的过量氧化,会导致系列非传染性病或恶化传染性病。因动物已建立了各种抗氧化体系,且饲料也是重要的抗氧化剂来源,故动物可生活在氧气环境中。因此在饲料与宿主之间还需调控氧化应激。  相似文献   

The effect of dosing with sodium hydroxide (NaOH−) on water pH and growth of Haliotis midae in an abalone serial-use raceway     

Matthew A. Naylor  Horst Kaiser  Clifford L. W. Jones 《Aquaculture International》2013,21(2):467-479

Abalone culture systems are characterised by high water exchange rates as abalone are sensitive to changes in water quality. To reduce the costs of pumping, serial reuse systems have been tested. As water pH can decline in these systems, this study determined the effect of raising pH through the addition of sodium hydroxide (NaOH^?) on weight gain, length gain and feed conversion ratio of H. midae in a serial-use raceway. Dosing with NaOH^? increased pH by 0.3, 0.27 and 0.21 units at positions 1, 2 and 3 of a serial-pass system, respectively. Weight gain (Wg) and length gain (Lg) were correlated with pH (Wg: F _{1, 16} = 16.35, P = 0.0009, r ² = 0.51; Lg: F _{1, 16} = 16.16, P = 0.0009, r ² = 0.50), and using pH, dissolved oxygen and free ammonia nitrogen as independent variables suggested that water pH was the best predictor for abalone growth.  相似文献   

Ontogenetic movements of juvenile blacktip reef sharks: evidence of dispersal and connectivity between coastal habitats and coral reefs     

A Chin  MR Heupel  CA Simpfendorfer  AJ Tobin 《水产资源保护:海洋与淡水生态系统》2013,23(3):468-474

Feline discrete high‐grade gastrointestinal lymphoma treated with surgical resection and adjuvant CHOP‐based chemotherapy: retrospective study of 20 cases          下载免费PDF全文

E. D. Gouldin  C. Mullin  M. Morges  S. J. Mehler  L.‐P. de Lorimier  C. Oakley  R. Risbon  L. May  S. A. Kahn  C. Clifford 《Veterinary and comparative oncology》2017,15(2):328-335

The aim of this retrospective study was to evaluate the outcome of cats treated with surgical intervention for a discrete intermediate‐/high‐grade gastrointestinal lymphoma prior to CHOP‐based chemotherapy. Variables including sex, breed, haematocrit, white blood cell count, serum albumin concentration, clinical stage of disease, gastrointestinal obstruction and peritonitis were assessed for their effect on survival. Twenty cats met the inclusion criteria with three cats still alive at the time of data analysis. The overall median survival time (MST) was 417 days (range: 12–2962 days). The disease‐free interval (DFI) was 357 days (range: 0–1585 days) with six cats still deemed in remission prior to death. Only clinical stage had a significant effect on both MST and DFI. Cats with discrete intermediate/high‐grade gastrointestinal lymphoma that undergo surgical resection followed by adjuvant CHOP chemotherapy may achieve acceptable overall survival times.  相似文献