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Caffeine intake by patients with autosomal dominant polycystic kidney disease
(Associação Brasileira de Divulgação Científica, 2012) Vendramini, L.C.; Nishiura, J.L.; Baxmann, A.C.; Heilberg, I.P.
Because caffeine may induce cyst and kidney enlargement in autosomal dominant polycystic kidney disease (ADPKD), we evaluated caffeine intake and renal volume using renal ultrasound in ADPKD patients. Caffeine intake was estimated by the average of 24-h dietary recalls obtained on 3 nonconsecutive days in 102 ADPKD patients (68 females, 34 males; 39 ± 12 years) and compared to that of 102 healthy volunteers (74 females, 28 males; 38 ± 14 years). The awareness of the need for caffeine restriction was assessed. Clinical and laboratory data were obtained from the medical records of the patients. Mean caffeine intake was significantly lower in ADPKD patients versus controls (86 vs 134 mg/day), and 63% of the ADPKD patients had been previously aware of caffeine restriction. Caffeine intake did not correlate with renal volume in ADPKD patients. There were no significant differences between the renal volumes of patients in the highest and lowest tertiles of caffeine consumption. Finally, age-adjusted multiple linear regression revealed that renal volume was associated with hypertension, chronic kidney disease stage 3 and the time since diagnosis, but not with caffeine intake. The present small cross-sectional study indicated a low level of caffeine consumption by ADPKD patients when compared to healthy volunteers, which was most likely due to prior awareness of the need for caffeine restriction. Within the range of caffeine intake observed by ADPKD patients in this study (0-471 mg/day), the renal volume was not directly associated with caffeine intake.
Low concentration fertigation solution allows greater macronutrient use efficiency in coffee seedlings
(Editora UFLA, 2021) Rosa, Kelly Martins; Paiva, Paulo Eduardo Branco; Coelho, Victor Peçanha de Miranda; Carvalho, Mychelle; Assis, Henrico Luis Bizão de
Coffee seedling production in cone-shaped containers and substrate results in lower sanitary risk and costs. With the use of small containers and sub strates with low fertilizer levels, fertigation is necessary for seedling development. An experiment was carried out with three macronutrient concentra tions (electrical conductivities of 1.0, 2.0 and 3.0 dS m-1) and a non-fertilized control using Coffea arabica cv. Topázio seedlings in 50 cm3 cone-shaped containers and composted pine bark-based substrate. The following fertilizers (expressed in g m-3 of water) were used in the nutrient solution with EC of 1.0 dS m-1: Ca(NO3)2 (400), KNO3 (250), MgSO4 (175), (NH4)PO4 (50) and ConMicros Standard® (25). In the solutions with 2.0 and 3.0 dS m-1, macronutrient concentration was doubled and tripled, while micronutrients remained the same. At four months we assessed EC and pH of the solution drained, shoot dry mass, shoot nutrient concentration and accumulation and macronutrient use efficiency. Fertigation with 1.0 and 2.0 dS m-1 produced seedlings with greater mass (+10%) than fertigation with 3.0 dS m-1, while higher macronutrient supplies increased shoot N, P, K, Mg and S concentration. Fertigation with 2.0 dS m-1 caused greater shoot N, P, K and Ca accumulation and this conductivity also resulted in higher accumulation of B, Fe, Mn and Zn without increasing the micronutrient supply. The response to the increase in Ca in the nutrient solution is evident in the accumulation of this nutrient in the plant but not its concentration, possibly due to the dilution effect. Micronutrient accumulation in this species is also more adequate for determining nutritional status than the concentration in the plant. The least concentrated macronutrient solution increases nutrient use efficiency in C. arabica seedlings as well as being economically and environmentally more sustainable.
Concentration and accumulation of micronutrients in robust coffee
(Editora da Universidade Estadual de Maringá - EDUEM, 2019) Dubberstein, Danielly; Partelli, Fabio Luiz; Espindula, Marcelo Curitiba; Dias, Jairo Rafael Machado
Knowledge on the dynamics of micronutrients in coffee tree assists nutritional diagnosis and fertilization management. Therefore, the objective of this study was to evaluate the concentration and accumulation of micronutrients in the leaves and fruits of Coffea canephora. The experiment was managed in crops propagated for 2.5 years in a split-plot-in-time scheme in which the main plots consisted of fertilized and not-fertilized plants, and the subplots stipulated the evaluation periods. The berries and leaves were collected every 28 days, starting from the first flowering to full maturity. The micronutrient content was determined by laboratory chemical analysis, and the accumulation of nutrients in the fruit (mg) was calculated by multiplying the dry matter of the berry (g) × nutrient concentration (mg kg−1). The results showed that fertilization infers the zinc concentration in the fruits and the concentration for manganese, iron and zinc in the leaves in the determined periods. Micronutrient accumulation curves followed the simple sigmoidal model, with accumulation increasing considerably as a function of fruit growth. Thus, fertilization based on micronutrients must be divided over stages with higher accumulation rates, considering the specific requirement of each nutrient.

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