Environmental impact of biogenic silver nanoparticles in soil and aquatic organisms

Synthetic silver nanoparticles (AgNPs) are being extensively used in our daily lives; however, they may also pose a risk to public health and environment. Nowadays, biological AgNPs are considered an excellent alternative, since their synthesis occurs by a green technology of low cost and easy scaling. However, studies with these biological nanomaterials (NM) are still limited. Thus, a more careful assessment of their industrial application, economic feasibility and ecotoxicological impacts is crucial. The aim of this study was to investigate the effects of different concentrations of mangrove fungus Aspergillus tubingensis AgNPs on the aerobic heterotrophs soil microorganisms, rice seeds (Oryza sativa) and zebrafish (Danio rerio). Biogenic AgNPs were less harmful for soil microbiota compared to AgNO3. On rice seeds, the AgNPs displayed a dose-dependent inhibitory effect on germination and their subsequent growth and development. The percentage of inhibition of rice seed germination was 30, 69 and 80% for 0.01, 0.1 and 0.5 mM AgNPs, respectively. After 24h of AgNPs exposition at a limit concentration of 0.2 mM, it did not induce mortality of the zebrafish D. rerio. Overall, A. tubingensis AgNPs can be considered as a suitable alternative to synthetic nanoparticles.

Cyclic electron flow, NPQ and photorespiration are crucial for the establishment of young plants of Ricinus communis and Jatropha curcas exposed to drought.

Although plant physiological responses to drought have been widely studied, the interaction between photoprotection, photorespiration and antioxidant metabolism in water-stressed plants is scarcely addressed. This study aimed to evaluate the physiological adjustments preserving photosynthesis and growth in two plant species with different tolerance to drought: Jatropha curcas and Ricinus communis. We measured stress indicators, gas exchange, photochemistry of PSII and PSI, antioxidant enzymes, cyclic electron flow and photorespiration. Physiological stress indicators associated with reduction in growth confirmed R. communis as sensitive and J. curcas as tolerant to drought. Drought induced loss of photosynthesis in R. communis, whereas J. curcas maintained higher leaf gas exchange and photochemistry under drought. In addition, J. curcas showed higher dissipation of excess energy and presented higher cyclic electron flow when exposed to drought. Although none of these mechanisms have been triggered in R. communis, this species showed increases in photorespiration. R. communis displayed loss of Rubisco content while the Rubisco relative abundance did not change in J. curcas under drought. Accordingly, the in vivo maximum Rubisco carboxylation rate (Vcmax ) and the maximum photosynthetic electron transport rate driving RuBP regeneration (Jmax ) were less affected in J. curcas. Both species displayed an efficient antioxidant mechanism by increasing activities of ascorbate peroxidase (APX) and superoxide dismutase (SOD). Overall, we suggest that the modulation of different photoprotective mechanisms is crucial to mitigate the effects caused by excess energy, maintaining photosynthetic apparatus efficiency and promoting the establishment of young plants of these two species under drought.

Produção e qualidade do leite de cabras de torneiros leiteiros / Milk production quality in dairy goats that participate in dairy tournaments in the state of Rio Grande do Norte, Brazil

O objetivo deste trabalho foi avaliar a produção diária, a qualidade microbiológica e físico-químicas do leite das cabras participantes de Torneios Leiteiros no Estado do Rio Grande do Norte, Brasil. Foram analisadas 111 amostras de leite de 106 cabras (39 Saanen, 6 Toggenburg e 61 mestiças) agrupadas em categorias pela ordem de parto (primíparas e pluríparas) e estágio de lactação [inicial (0 a 30 dias), pico (30 a 45 dias) e pós-pico (mais de 45 dias)], utilizando o delineamento inteiramente casualisado. As cabras pluríparas apresentaram maiores médias de produção no início (4,41 kg/dia) e no pico (5,42 kg/dia) de lactação. Entre raças não houve diferença para produção media (4,62 kg/dia), ponto de congelamento (-0,488° C), pH (6,64), densidade (1,030 g/L), gordura (3,60%), proteína (2,90%), lactose (4,89%), extrato seco desengordurado (8,41%) e extrato seco total (12,06%). As análises microbiológicas revelaram a presença de mesófilos e coliformes fecais, sem diferença entre as ordens de parto ou entre raças. Cabras pluríparas apresentaram maiores produções de leite, mas não diferiram das primíparas quanto à composição, características físicas e microbiota do leite. As amostras de leite dos três genótipos (Saanen, Toggenburg e mestiças) analisados mostraram características físico-químicas, microbiológicas e de produção semelhantes.(AU)

The objective of this study was to evaluate the average daily production, the physicochemical components and microbiologicalagents in milk of primiparous and multiparous dairy goats that participate in dairy tournaments in the state of Rio Grande do Norte, Brazil. Analyses were carried out on 111 samples of goat milk from 106 goats (39 Saanen, 6 Toggenburg and 61 crossbred) grouped into categories by number of parity (primiparous and multiparous) and stage of lactation [initial (0 to 30 days), peak (30 to 45 days) and decrease (over 45 days)]. The data were analyzed in a completely randomizeddesign. The multiparous goats had higher average production at the beginning (4.41 kg/day) and peak (5.42 kg/day) of lactation. Between breeds there was no difference for average production(4.62 kg/day), freezing point (-0.488° C), pH (6.64), density (1.030 g/L), fat (3.60%), protein (2.90%) lactose (4.89%), dry extract (8.41%) or total solids (12.06%). Mesophiles (log CFU/mL) and fecal coliforms (log MPN/mL) were found in milk from goats, but no difference was observed between the orders of parity or between breeds. Multiparous goats had higher milk production, but did not differ from the primiparous goats regarding the composition, physical characteristics and microbiology of milk. The milk of 3 breeds (Saanen, Toggenburg and crossbred) presented similar physico-chemical, microbiological and production characteristics.(AU)

Produção e qualidade do leite de cabras de torneios leiteiros

The objective of this study was to evaluate the average daily production, the physicochemical components and microbiological agents in milk of primiparous and multiparous dairy goats that participate in dairy tournaments in the state of Rio Grande do Norte, Brazil. Analyses were carried out on 111 samples of goat milk from 106 goats (39 Saanen, 6 Toggenburg and 61 crossbred) grouped into categories by number of parity (primiparous and multiparous) and stage of lactation [initial (0 to 30 days), peak (30 to 45 days) and decrease (over 45 days)]. The data were analyzed in a completely randomized design. The multiparous goats had higher average production at the beginning (4.41 kg/day) and peak (5.42 kg/day) of lactation. Between breeds there was no difference for average production (4.62 kg/day), freezing point (-0.488º C), pH (6.64), density (1.030 g/L), fat (3.60%), protein (2.90%) lactose (4.89%), dry extract (8.41%) or total solids (12.06%). Mesophiles (log CFU/mL) and fecal coliforms (log MPN/mL) were found in milk from goats, but no difference was observed between the orders of parity or between breeds. Multiparous goats had higher milk production, but did not differ from the primiparous goats regarding the composition, physical characteristics and microbiology of milk. The milk of 3 breeds (Saanen, Toggenburg and crossbred) presented similar physico-chemical, microbiological and production characteristics.

O objetivo deste trabalho foi avaliar a produção diária, a qualidade microbiológica e físico-químicas do leite das cabras participantes de Torneios Leiteiros no Estado do Rio Grande do Norte, Brasil. Foram analisadas 111 amostras de leite de 106 cabras (39 Saanen, 6 Toggenburg e 61 mestiças) agrupadas em categorias pela ordem de parto (primíparas e pluríparas) e estágio de lactação [inicial (0 a 30 dias), pico (30 a 45 dias) e pós-pico (mais de 45 dias)], utilizando o delineamento inteiramente casualisado. As cabras pluríparas apresentaram maiores médias de produção no início (4,41 kg/dia) e no pico (5,42 kg/dia) de lactação. Entre raças não houve diferença para produção media (4,62 kg/dia), ponto de congelamento (-0,488º C), pH (6,64), densidade (1,030 g/L), gordura (3,60%), proteína (2,90%), lactose (4,89%), extrato seco desengordurado (8,41%) e extrato seco total (12,06%). As análises microbiológicas revelaram a presença de mesófilos e coliformes fecais, sem diferença entre as ordens de parto ou entre raças. Cabras pluríparas apresentaram maiores produções de leite, mas não diferiram das primíparas quanto à composição, características físicas e microbiota do leite. As amostras de leite dos três genótipos (Saanen, Toggenburg e mestiças) analisados mostraram características físico-químicas, microbiológicas e de produção semelhantes.

Produção e qualidade do leite de cabras de torneiros leiteiros / Milk production quality in dairy goats that participate in dairy tournaments in the state of Rio Grande do Norte, Brazil

O objetivo deste trabalho foi avaliar a produção diária, a qualidade microbiológica e físico-químicas do leite das cabras participantes de Torneios Leiteiros no Estado do Rio Grande do Norte, Brasil. Foram analisadas 111 amostras de leite de 106 cabras (39 Saanen, 6 Toggenburg e 61 mestiças) agrupadas em categorias pela ordem de parto (primíparas e pluríparas) e estágio de lactação [inicial (0 a 30 dias), pico (30 a 45 dias) e pós-pico (mais de 45 dias)], utilizando o delineamento inteiramente casualisado. As cabras pluríparas apresentaram maiores médias de produção no início (4,41 kg/dia) e no pico (5,42 kg/dia) de lactação. Entre raças não houve diferença para produção media (4,62 kg/dia), ponto de congelamento (-0,488° C), pH (6,64), densidade (1,030 g/L), gordura (3,60%), proteína (2,90%), lactose (4,89%), extrato seco desengordurado (8,41%) e extrato seco total (12,06%). As análises microbiológicas revelaram a presença de mesófilos e coliformes fecais, sem diferença entre as ordens de parto ou entre raças. Cabras pluríparas apresentaram maiores produções de leite, mas não diferiram das primíparas quanto à composição, características físicas e microbiota do leite. As amostras de leite dos três genótipos (Saanen, Toggenburg e mestiças) analisados mostraram características físico-químicas, microbiológicas e de produção semelhantes.

The objective of this study was to evaluate the average daily production, the physicochemical components and microbiologicalagents in milk of primiparous and multiparous dairy goats that participate in dairy tournaments in the state of Rio Grande do Norte, Brazil. Analyses were carried out on 111 samples of goat milk from 106 goats (39 Saanen, 6 Toggenburg and 61 crossbred) grouped into categories by number of parity (primiparous and multiparous) and stage of lactation [initial (0 to 30 days), peak (30 to 45 days) and decrease (over 45 days)]. The data were analyzed in a completely randomizeddesign. The multiparous goats had higher average production at the beginning (4.41 kg/day) and peak (5.42 kg/day) of lactation. Between breeds there was no difference for average production(4.62 kg/day), freezing point (-0.488° C), pH (6.64), density (1.030 g/L), fat (3.60%), protein (2.90%) lactose (4.89%), dry extract (8.41%) or total solids (12.06%). Mesophiles (log CFU/mL) and fecal coliforms (log MPN/mL) were found in milk from goats, but no difference was observed between the orders of parity or between breeds. Multiparous goats had higher milk production, but did not differ from the primiparous goats regarding the composition, physical characteristics and microbiology of milk. The milk of 3 breeds (Saanen, Toggenburg and crossbred) presented similar physico-chemical, microbiological and production characteristics.

Surgical removal of small petroclival meningiomas.

UNLABELLED: Treatment of large petroclival meningiomas causing brain stem compression is surgical removal followed by radiotherapy or radiosurgery if the lesion was partially resected. The management of small petroclival meningiomas is, however, controversial. Clinical observation, radiosurgery and surgical removal are the options of treatment. The natural history of these tumours is not well known. Published series of patients treated with radiosurgery are not comparable with surgical series because the latter also includes large size tumours. In this paper we present a series of 18 patients with small petroclival meningiomas (diameter

Risk of bacterial infection in patients under intravenous iron therapy: dose versus length of treatment.

Some studies have suggested that intravenous iron therapy may be associated with an increased risk of infection. We analyzed the incidence of bacterial infection in 111 hemodialysis patients. Group 1 (n = 39, transferrin saturation <20%) received 10 doses of 100 mg of intravenous iron saccharate, 3 doses per week (28 treatment days); Group 2 (n = 13, transferrin saturation <20%) received 20 doses, 3 doses per week (70 treatment days); and Group 3 (n = 59, transferrin saturation 20-50%) received 10 doses, 1 dose per week (70 treatment days). The follow-up was 150 days for all groups, and all infectious episodes were recorded. Pulmonary infection was the most frequent event observed in all of the groups. In an incidence-density analysis, Group 2, which received a total of 20 doses, presented a significantly higher incidence of infection than Group 3, which received only 10 doses over the same period (0.13 versus 0.06 infections per patient per month, p = 0.04). No difference was observed between Groups 1 and 2 suggesting that the risk of infection during iron therapy is dose dependent rather than time length dependent.