Divalent metal nanoparticles     

Devries GA  Brunnbauer M  Hu Y  Jackson AM  Long B  Neltner BT  Uzun O  Wunsch BH  Stellacci F 《Science (New York, N.Y.)》2007,315(5810):358-361

Nanoparticles can be used as the building blocks for materials such as supracrystals or ionic liquids. However, they lack the ability to bond along specific directions as atoms and molecules do. We report a simple method to place target molecules specifically at two diametrically opposed positions in the molecular coating of metal nanoparticles. The approach is based on the functionalization of the polar singularities that must form when a curved surface is coated with ordered monolayers, such as a phase-separated mixture of ligands. The molecules placed at these polar defects have been used as chemical handles to form nanoparticle chains that in turn can generate self-standing films.  相似文献   

Mothers' transitions from welfare to work and the well-being of preschoolers and adolescents     

Chase-Lansdale PL  Moffitt RA  Lohman BJ  Cherlin AJ  Coley RL  Pittman LD  Roff J  Votruba-Drzal E 《Science (New York, N.Y.)》2003,299(5612):1548-1552

Results from a longitudinal study of 2402 low-income families during the recent unprecedented era of welfare reform suggest that mothers' transitions off welfare and into employment are not associated with negative outcomes for preschoolers (ages 2 to 4 years) or young adolescents (ages 10 to 14 years). Indeed, no significant associations with mothers' welfare and employment transitions were found for preschoolers, and the dominant pattern was also of few statistically significant associations for adolescents. The associations that did occur provided slight evidence that mothers' entry into the labor force was related to improvements in adolescents' mental health, whereas exits from employment were linked with teenagers' increased behavior problems.  相似文献   

NITROGEN ACCUMULATION IN SHOOTS AS A FUNCTION OF GROWTH STAGE OF CORN AND WINTER WHEAT     

Kefyalew Girma  Starr Holtz  Brenda Tubaña  John Solie  William Raun 《Journal of plant nutrition》2013,36(2):165-182

Midseason fertilizer nitrogen (N) rates based on predicted yields can be projected if the quantity of N accumulated in winter wheat (Triticum aestivum L.) and corn (Zea mays L.) is known especially early in the growing season. This study was conducted in 2006 and 2007 to establish the amount of N accumulated in corn and winter wheat over the entire growing season. Plots representing three N fertilization rates 0, 45, and 90 kg ha^?1 at Stillwater and 0, 67, and 112 kg ha^?1 at Lahoma were selected from two long-term wheat experiments located at research stations in Stillwater and Lahoma, Oklahoma. For corn, three N fertilization rates 0, 112 and 224 kg ha^?1 at Lake Carl Blackwell and 0, 56 and 112 kg ha^?1 at Perkins were selected from N studies, located at research stations near Lake Carl Blackwell and Perkins, Oklahoma. Sequential aboveground biomass samples were collected from 1 m² area of wheat and 1.5 m long row (0.76 cm spacing) for corn throughout their respective growing seasons. In general, this work showed that more than 45% of the maximum total N accumulated could be found in corn plants by growth stage V8 (8th leaf collar fully unfolded). For winter wheat, more than 61% of the maximum total N accumulated at later stages of growth could be accounted for by Feekes growth stage 5 (F5, leaf strongly erected). Our findings are consistent with those of others showing that yield potential can be predicted at mid-season since such a large percentage of the total N accumulated was accounted for early on in the growing cycle of either wheat or corn.  相似文献   

Sheep immunoglobulins and their transmission to the neonatal lamb     

M.J. Siegel  Brenda J. Knowlton 《New Zealand veterinary journal》2013,61(12):361-365

Extract

In the past decade great strides have been made in clarifying the types of immunoglobulins found in various species of domestic animals. This review summarizes the information presently* * This review cites material published up to the end of 1976. available on sheep immunoglobulins — their classes, quantity and distribution in serum and colostrum. the review also highlights recent studies of fetal immunological competence, presucking lamb serum immunoglobulins, the process by which colostral immunoglobulins are passively transferred to the neonate, and the effects both of colostrum administration and deprivation on the newborn lamb.  相似文献   

Candida peritonitis in dogs: report of 5 cases     

Katy Bradford  Jim Meinkoth  Kelci McKeirnen  Brenda Love 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2013,42(2):227-233

Candida peritonitis is reported in people and is associated with significant morbidity and mortality compared with sterile or bacterial peritonitis. Recognized predisposing risk factors include peritoneal dialysis, hollow viscous organ perforation, abdominal surgery, inflamed intestinal mucosa, antimicrobial administration, and immunosuppression. In this report, we describe 5 cases of dogs with peritonitis complicated by Candida spp; 3 dogs with C albicans, one dog with C albicans and C glabrata, and one dog with C glabrata only. The 3 dogs with C albicans peritonitis presented with duodenal perforation due to NSAID therapy, intestinal resection and anastomosis following postspay‐surgery dehiscence, and intestinal foreign body removal. The 2 dogs with C glabrata peritonitis had undergone cholecystectomy due to gall bladder rupture and dehiscence of intestinal biopsy removal sites following exploratory laparatomy. In all cases, initial diagnosis of fungal peritonitis was made via cytologic examination of peritoneal effusions, which revealed marked pyogranulomatous inflammation with numerous 3–8 μm oval, deeply basophilic yeast organisms with thin clear capsules noted within phagocytes and extracellularly. In addition, germ tube formation, hyphae, and pseudohyphae were rarely seen in some of the cases with pure C albicans. Identity of the organisms was determined by culture in all cases and confirmed by PCR in 3 cases. Candida spp. are commensals normally inhabiting the alimentary, the upper respiratory, and the lower urogenital tracts of mammals. They are opportunistic pathogens that can invade and colonize tissue when a patient is immune‐compromised or there is disruption of the mucosal barrier. Candida peritonitis should be considered in patients with peritoneal contamination with gastrointestinal or biliary contents.  相似文献   

Contribution of street foods to the dietary needs of street food vendors in Kampala, Jinja and Masaka districts, Uganda     

Namugumya BS  Muyanja C 《Public health nutrition》2012,15(8):1503-1511

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Influence of stocking density on the behaviour of juvenile Litopenaeus vannamei (Boone, 1931)          下载免费PDF全文

Felipe P. da Costa  Brenda Suellen Franklin de Farias Gomes  Silvia Dinara do Nascimento Alves Pereira  Maria de Fátima Arruda 《Aquaculture Research》2016,47(3):912-924

Applied ethology can help to improve Litopenaeus vannamei aquaculture. Our purpose was to demonstrate an influence of stocking density on behaviour. The shrimp were first distributed in aquaria and observed via an ad libitum observational method to construct an ethogram of social and feeding behavioural categories. The resulting ethogram consisted of retreat, cannibalism, getting to the feeding tray, occupying the feeding tray and getting feed. We then kept shrimp in aquaria at densities of 50, 75 and 100 animals m^?2 and observed them via a behavioural sampling method using our ethogram as well as focal animal sampling of behaviours derived from the literature. These literature‐derived behaviours consisted of inactivity, feeding, crawling, exploration, burying, swimming and cleaning. We found that stocking density affects the behaviour of the shrimp. Optimal searching and feeding and a low frequency of crawling and swimming occurred at a density of 50 animals m^?2, indicating a higher potential for growth and welfare at this density.  相似文献   

Clopidogrel induced suppression of bovine platelet activation in vitro and a preliminary study of its effect on the development of Mannheimia haemolytica induced pneumonia     

Coomber BL  Mitchell GB  Starr AE  Minhas K  Tamblyn A  Shewen PE  Gentry PA 《Veterinary journal (London, England : 1997)》2006,171(1):126-134

We report here on the influence of the platelet antagonist clopidogrel (Plavix) on bovine platelet function. We first evaluated the capacity of clopidogrel to inhibit adenosine diphosphate (ADP)-stimulated platelet function in the bovine species, using an ex vivo approach with blood from treated animals. Platelets isolated from treated calves displayed rapid and consistent reduction in function (aggregation, thromboxane production) upon ADP, but not platelet activating factor (PAF), stimulation. We then examined the possibility that clopidogrel could influence Mannheimia haemolytica pneumonia pathobiology using an experimental challenge model. We were unable to detect significant differences between clopidogrel treated and untreated animals when challenged with intra-tracheal inoculation of M. haemolytica. There was a trend towards inhibition of platelet degranulation in the affected regions of lungs from clopidogrel treated calves, and pre-treated challenged animals had similar amounts of fibrin deposition and enhanced fibrous tissue formation in their lungs when compared with control counterparts.  相似文献   

ECG of the month. Transvenous pacing of the RVA     

Weissman BL  Estrada AH 《Journal of the American Veterinary Medical Association》2006,228(7):1025-1027

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Evaluation of factors associated with survival in dogs with untreated nasal carcinomas: 139 cases (1993-2003)     

Rassnick KM  Goldkamp CE  Erb HN  Scrivani PV  Njaa BL  Gieger TL  Turek MM  McNiel EA  Proulx DR  Chun R  Mauldin GE  Phillips BS  Kristal O 《Journal of the American Veterinary Medical Association》2006,229(3):401-406

OBJECTIVE: To evaluate factors associated with survival in dogs with nasal carcinomas that did not receive treatment or received only palliative treatment. DESIGN: Retrospective case series. ANIMALS: 139 dogs with histologically confirmed nasal carcinomas. PROCEDURES: Medical records, computed tomography images, and biopsy specimens of nasal carcinomas were reviewed. Only dogs that were not treated with radiation, surgery, chemotherapy, or immunotherapy and that survived > or = 7 days from the date of diagnosis were included. The Kaplan-Meier method was used to estimate survival time. Factors potentially associated with survival were compared by use of log-rank and Wilcoxon rank sum tests. Multivariable survival analysis was performed by use of the Cox proportional hazards regression model. RESULTS: Overall median survival time was 95 days (95% confidence interval [CI], 73 to 113 days; range, 7 to 1,114 days). In dogs with epistaxis, the hazard of dying was 2.3 times that of dogs that did not have epistaxis. Median survival time of 107 dogs with epistaxis was 88 days (95% CI, 65 to 106 days) and that of 32 dogs without epistaxis was 224 days (95% CI, 54 to 467 days). CONCLUSIONS AND CLINICAL RELEVANCE: The prognosis of dogs with untreated nasal carcinomas is poor. Treatment strategies to improve outcome should be pursued.  相似文献