The Radiocarbon Laboratory of the Universidade Federal Fluminense, in Brazil, has been successfully applying the zinc reduction method for graphitization of carbon samples since the development of ...its early protocols in 2009. Successive methodological research aiming to improve and, ultimately, optimize the precision and accuracy of our results indicates that graphitization temperatures as low as 460°C promote erratic 13C isotopic fractionation, but an approximately constant fractionation of about –5‰ is achieved at 520°C. In this work, we present isotope ratio mass spectrometry (IRMS) δ13C results for 14C reference materials graphitized at 550°C with variable amounts of zinc. Based on the results obtained from the addition of 20, 35, and 50 mg of zinc, we conclude that a slightly lower variation in 13C isotope fractionation during graphitization is obtained with less zinc. Moreover, the average isotopic fractionation is not altered by increasing the graphitization temperature from 520°C to 550°C.
An adult, captive raised male Valley quail (Callipepla californica) acquired by a southern Brazilian aviary suddenly showed severe apathy, dyspnea and diarrhea, and died 18 hours after the onset of ...illness. At necropsy, pale muscles and whitish areas in the heart, splenomegaly, hepatomegaly, and consolidated red lungs were observed. Histological findings were mainly mononuclear inflammation with necrosis of liver, heart, spleen, bone marrow and lung. There were large numbers of Toxoplasma gondii tachyzoitesorganisms in the liver, heart, spleen, bone marrow, lungs, trachea, kidneys, adrenal glands, testes, intestines, and pancreas. These organisms were seen free in the organs' stroma or within macrophages and stained positively with polyclonal antiserum to T. gondii. Genomic DNA was extracted from the tissues and PCR was used to target the B1 gene of T. gondii. The genotypic characterization by PCR-RFLP with 11 markers (SAG1, SAG2 and alt. SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico and CS3) revealed the ToxoDB-PCR-RFLP #87 genotype, the same as previously identified in a backyard chicken (TgCkBr156) in Rio Grande do Sul, Brazil.
Fossil fuel-derived CO2 (Cff) emission patterns and their point sources across the Rio de Janeiro megacity and state were estimated from a single regional-scale Δ14C distribution map based on ...isotopic measurements of ipê leaves (Tabebuia, a popular flowering deciduous perennial tree). Data from multi-year sampling (i.e., 2014–2016) was renormalized to reflect 14C signatures of the 2015 calendar year. Spatial variability in Δ14C ranges from a maximum of 27.1 ± 0.4‰ (city of Petrópolis, a higher-elevation municipality) to a minimum of −43.6 ± 1.4‰ (i.e., approximately 27.6 ± 1 ppm of Cff — Santo Cristo, a district within the Rio de Janeiro city). Overall, higher Δ14C values correlate well with green habitats and high elevation areas, while lower values are associated with Cff emissions in densely populated areas with higher industrial and traffic footprints. Cff emissions are higher where local air circulation is poor, such as the area surrounding Guanabara Bay. Other areas with significantly higher Cff emissions were the Paraíba Valley and Mountain regions. These results may be explained by atmospheric transport of CO2 from neighboring states, such as São Paulo and Minas Gerais, and by the predominant west winds and the limited regional air flow created by large topographic features. Lower Cff emissions were observed in the Northwest and Lakes regions, which are dominated by agriculture and tourism activities. Our results highlight the potential of directly estimating Cff for studying urban landscapes in the southern region of Brazil through 14C time-integrated distribution mapping of ipê leaves. The method could also be used to augment greenhouse gas (GHG) emissions inventory studies trends in partitioning Cff from CO2 of bio-template sustainable sources.
•Ipê leaves have been successfully used to assess the emission of 14C-depleted CO2ff.•CO2ff was associated with traffic footprint, industrial processes and prevalent winds.•Deciduous tree leaf analysis is important for mitigating local CO2ff emissions.
•Erg6 is required for Cryptococcus neoformans high temperature growth.•ERG6 deletion impairs susceptibility to stress and antifungal agents.•Sterol membrane composition affects virulence of human ...fungal pathogen.
Ergosterol is the most important membrane sterol in fungal cells and a component not found in the membranes of human cells. We identified the ERG6 gene in the AIDS-associated fungal pathogen, Cryptococcus neoformans, encoding the sterol C-24 methyltransferase of fungal ergosterol biosynthesis. In this work, we have explored its relationship with high-temperature growth and virulence of C. neoformans by the construction of a loss-of-function mutant. In contrast to other genes involved in ergosterol biosynthesis, C. neoformans ERG6 is not essential for growth under permissive conditions in vitro. However, the erg6 mutant displayed impaired thermotolerance and increased susceptibility to osmotic and oxidative stress, as well as to different antifungal drugs. Total lipid analysis demonstrated a decrease in the erg6Δ strain membrane ergosterol content. In addition, this mutant strain was avirulent in an invertebrate model of C. neoformans infection. C. neoformans Erg6 was cyto-localized in the endoplasmic reticulum and Golgi complex. Our results demonstrate that Erg6 is crucial for growth at high temperature and virulence, likely due to its effects on C. neoformans membrane integrity and dynamics. These pathogen-focused investigations into ergosterol biosynthetic pathway components reinforce the multiple roles of ergosterol in the response of diverse fungal species to alterations in the environment, especially that of the infected host. These studies open perspectives to understand the participation of ergosterol in mechanism of resistance to azole and polyene drugs. Observed synergistic growth defects with co-inhibition of Erg6 and other components of the ergosterol biosynthesis pathway suggests novel approaches to treatment in human fungal infections.
This study investigated the potential use of topically and orally administered propolis extracts to prevent UV irradiation-induced oxidative stress in skin. The results illustrated that green ...propolis extract (GPE) contained greater amounts of polyphenols, coumaric acid, drupanin, baccharin and artepillin C than did brown propolis extract (BPE). GPE showed higher antioxidant activity than BPE when the IC50 (concentration that caused 50% inhibition) values were compared. Interesting, the oral treatment of hairless mice demonstrated a recovery of 30.0% for GPE and 22.8% for BPE with respect to UV irradiation-induced GSH depletion. The topical pretreatment of animals with both propolis extract solutions recovered around 14.0% of the depleted GSH. However, the employed treatments did not inhibit the increase of cutaneous proteinase secretion/activity caused by irradiation. These findings indicate that despite differences in composition and antioxidant properties, GPE and BPE both successfully prevent UV-induced GSH depletion in vivo and are both promising antioxidant systems against oxidative stress in skin. Based on these findings, complementary studies should be performed to enhance our understanding of the protective effects of propolis extracts in skin.
Memory is an important cognition function, being fundamental to the development and independence of individuals. Our aim was to investigate the influence apolipoprotein E (APOE) and angiotensin ...I-converting enzyme (ACE) polymorphism and ACE inhibitors use, besides their interaction on memory performance of healthy subjects over 50 years. The sample consisted of 205 subjects assessed for five types of episodic memory, using Wechsler Memory Scale-Revised (WMS-R), who answered a questionnaire about drug use and were assessed for the
ACE
insertion/deletion polymorphism and
APOE
polymorphism. We found no influence of the
APOE
gene. The use of ACE inhibitors beneficially influenced learning ability scores (
p
= 0.02). Besides, I allele carriers of
ACE
polymorphism showed higher verbal memory scores compared with homozygous DD. Also, we observed an interaction influencing learning ability between the
ACE
polymorphism and the use of inhibitors, the beneficial influence of the I allele was present only in individuals who make use of ACE inhibitors. We conclude that the
ACE
gene has influence on memory performance, and that this influence is modulated by ACE inhibitors use.
Evidence shows that sunscreens undergo degradation processes induced by UV irradiation forming free radicals, which reduces skin protection. In this regard, the biological effects of three commercial ...sunscreen formulations upon UVB irradiation in the skin were investigated. The three formulations had in common the presence of benzophenone-3 added with octyl methoxycinnamate or octyl salycilate or both, which are regular UV filters in sunscreens. The results show that formulations F1 and F2 presented partial degradation upon UVB irradiation. Formulations F1 and F2 presented higher skin penetration profiles than F3. None of the formulations avoided UVB irradiation-induced GSH depletion, but inhibited reduction of SOD activity, suggesting the tested formulations did not present as a major mechanism inhibiting all UVB irradiation-triggered oxidative stress pathways. The formulations avoided the increase of myeloperoxidase activity and cytokine production (IL-1β and TNF-α), but with different levels of protection in relation to the IL-1β release. Concluding, UVB irradiation can reduce the stability of sunscreens, which in turn, present the undesirable properties of reaching viable skin. Additionally, the same SPF does not mean that different sunscreens will present the same biological effects as SPF is solely based on a skin erythema response. This found opens up perspectives to consider additional studies to reach highly safe sunscreens.
•None of the tested formulations avoided UVB irradiation-induced GSH depletion.•The formulations inhibited reduction of SOD activity.•The formulations avoided the increase of MPO activity and cytokine production.•The same SPF does not mean that different sunscreens will present the same protection.
Lemes, S, Simões, HG, Moreira, SR, Lima, RM, Almeida, JA, Ribeiro, F, Puga, GM, and Campbell, CSG. Physiological responses to a tap dance choreographycomparisons with graded exercise test and ...prescription recommendations. J Strength Cond Res 24(7)1954-1959, 2010-The aim of this study was to analyze the physiological responses to a tap dance choreography and to compare with those observed during a maximal treadmill exercise test, in tap dancers. Eight women (19.6 ± 2.4 years; 162.3 ± 4.4 cm; 54.0 ± 2.3 kg; 20.5 ± 1.4 kg·m; and 5.1 ± 2.6 years of tap dance training) were submitted to the following procedures(a) graded exercise test (GXT) on a treadmill until volitional exhaustion with 0.8 km·h of increment at each 3 and 1 minute of interval between stages and (b) tap dance choreography (TAP)-“The Shim Sham Shimmy”-consisting of 9 stages of 3 minutes with 1-minute rest between stages. Expired gas analyses were performed in all experimental sessions, providing breath-by-breath values for respiratory exchange rate (RER), oxygen uptake ( o2), and carbon dioxide production (CO2). Heart rate (HR) and rate of perceived exertion (RPE) were also measured. During the rest period between stages, blood samples (25 μl) were collected from the ear lobe for lactate threshold (LT) determination. It was observed that at the end of the TAP, subjects achieved an average of 83.8 ± 6.2% of the HRmax and 68.9 ± 11.3% of the o2max, both previously identified in the GXT. The choreography demanded 204.7 ± 31.3 kcal, an average RER of 0.88 ± 0.05 and mean RPE of 13 ± 2. The o2, HR, and RPE values did not significantly differ from those at the LT intensity identified during the GTX. Based on the present results, it was concluded that the TAP performance in the “The Shim Sham Shimmy” choreography elicited acute physiologic responses similar to those observed at the LT intensity, thus suggesting that Tap Dance constitutes a useful exercise modality for aerobic fitness and cardiovascular health improvements.
Swelling, pain and trismus are undesirable consequences of impacted mandibular third-molar extraction. The authors conducted a study to evaluate the effectiveness of cryotherapy, the therapeutic use ...of cold, in reducing undesirable consequences after surgery.
Fourteen patients aged 20 to 28 years comprised the sample. The authors extracted two impacted mandibular third molars at different times from each patient. Immediately after surgery, the patient underwent cryotherapy on one side for 30 minutes every one and one-half hours for 48 hours when he or she was awake. The patient did not receive cryotherapy on the other side. The authors performed clinical examinations to measure trismus and swelling before surgery, immediately after surgery and 24 and 48 hours after surgery.
The authors compared both sides for differences in swelling, pain and trismus in each patient. The results showed significant statistical differences in two of the five points that were used to measure the swelling (Wilcoxon nonparametric signed rank test of linear distances between the angle of the mandible to the pogonion and to the tragus). They found statistical differences between the two sides in relation to the pain; however, they found no significant differences in relation to trismus.
Cryotherapy was effective in reducing swelling and pain in this sample. Despite playing no role in the reduction of trismus, cryotherapy was effective in reducing swelling and pain in this sample, and the authors still recommend it be used.
Cryotherapy is helpful after third-molar extraction. Further studies need to be conducted that use larger samples of patients and other types of therapy, such as low-level laser therapy.
Several scientific expeditions surveyed the ocean during the 19th century, gathering a wealth of interdisciplinary data as well as samples of different kinds. The latter are currently held by museums ...worldwide, and are the subject of study in different sciences, offering a unique opportunity to access information which is not readily available elsewhere. This is the case for research involving the offset in 14C (or radiocarbon) activity between the ocean and the atmosphere, termed the Marine Reservoir Effect (MRE), which is responsible for apparent 14C ages in marine material. The quantification of this discrepancy is crucial for the 14C dating tool since corrections must be applied for the accurate calibration of marine 14C ages. Nevertheless, the difficulty of finding suitable material for assessing the MRE contributes to the current scenario of scarce and patchy data. Here we propose the use of samples collected during well-documented 19th-century scientific expeditions in order to overcome the lack of information that prevents the use of many museum specimens in MRE studies. Approximately 60 mollusk shells and a sea urchin, collected from the coast of Brazil, were analysed for their radiocarbon age, δ13C and δ18O. The MRE is variable, with considerably high values occurring at specific spots along the shoreline. The data indicate a rather large area of upwelling influence on the southeastern coast of Brazil and possible dissolution of 14C-free limestone in the northeast. The results shed light on processes affecting the 14C concentration of Brazilian coastal waters, bearing implications for palaeoenvironmental and archaeological studies performed in the region. Moreover, the data generated in this study will be useful for the validation of 14C simulations in numerical models. Finally, this paper offers a discussion of the importance of natural history collections which looks beyond the preservation of our biodiversity.
PDF
