On the use of stereodynamical effects to control cold chemical reactions: The H + D2 ⟷ D + HD case study.

Quantum calculations are reported for the stereodynamic control of the H + D2 ↔ D + HD chemical reaction in the energy range of 1-50 K. Stereodynamic control is achieved by a formalism similar to that reported by Perreault et al. [Nat. Chem. 10, 561 (2018)] in recent experimental works in which the alignment of the molecular bond axis relative to the incident relative velocity is controlled by selective preparations of the molecule in a specific or superposition of magnetic projection quantum numbers of the initial molecular rotational level. The approach presented here generalizes the experimental scheme of Perreault et al. and offers additional degree of control through various experimental preparations of the molecular alignment angle. Illustrative results presented for the H + D2 and D + HD reactions show significant control with the possibility of turning the reaction completely on or off with the appropriate stereodynamic preparation of the molecular state. Various scenarios for maximizing and minimizing the reaction outcomes are identified with the selective preparation of molecular rotational states.

Salt stress differentially regulates mobilisation of carbon and nitrogen reserves during seedling establishment of Pityrocarpa moniliformis.

Seedling establishment is a critical step in environment colonisation by higher plants that frequently occurs under adverse conditions. Thus, we carried out an integrated analysis of seedling growth, water status, ion accumulation, reserve mobilisation, metabolite partitioning and hydrolase activity during seedling establishment of the native Caatinga species Piptadenia moniliformis (Benth.) Luckow & R.W. Jobson under salinity. Two-day-old seedlings were cultivated in vitro for 4 days in water agar (control) or supplemented with 50 or 100 mm NaCl. Biochemical determinations were performed according to standard spectrophotometric protocols. We found that 100 mm NaCl stimulated starch degradation, amylase activity and soluble sugar accumulation, but limited storage protein hydrolysis in the cotyledons of P. moniliformis seedlings. Although Na+ accumulation in the seedling affected K+ partitioning between different organs, it was not possible to associate the salt-induced changes in reserve mobilisation with Na+ toxicity, or water status, in the cotyledons. Remarkably, we found that starch content increased in the roots of P. moniliformis seedlings under 100 mm NaCl, probably in response to the toxic effects of Na+ . The mobilisation of carbon and nitrogen reserves is independently regulated in P. moniliformis seedlings under salt stress. The salt-induced delay in seedling establishment and the resulting changes in the source-sink relationship may lead to storage protein retention in the cotyledons. Possibly, the intensification of starch mobilisation in the cotyledons supported starch accumulation in the root as a potential mechanism to mitigate Na+ toxicity.

A new species of Astyanax (Characiformes: Characidae) from Dolina Água Milagrosa, Rio Paraguai basin, Mato Grosso, Brazil.

A new species of Astyanax is described from the upper Rio Paraguai basin, Mato Grosso State, Brazil. The new species can be distinguished from congeners by having the body intensely yellowish in life (v. silvery, reddish or lightly yellow) and by morphometric and meristics traits. Astyanax dolinae n. sp. cannot be assigned to any of the Astyanax species complex currently recognized for the genus. It is only known from the Dolina Água Milagrosa, a karstic sinkhole lake, entirely fed by groundwater, surrounded by Cerrado, the savannah-like vegetation of central South America.

Rotationally inelastic collisions of H2+ ions with He buffer gas: Computing cross sections and rates.

We present quantum calculations for the inelastic collisions between H2+ molecules, in rotationally excited internal states, and He atoms. This work is motivated by the possibility of experiments in which the molecular ions are stored and translationally cooled in an ion trap and a He buffer gas is added for deactivation of the internal rotational population, in particular at low (cryogenic) translational temperatures. We carry out an accurate representation of the forces at play from an ab initio description of the relevant potential energy surface, with the molecular ion in its ground vibrational state, and obtain the cross sections for state-changing rotationally inelastic collisions by solving the coupled channel quantum scattering equations. The presence of hyperfine and fine structure effects in both ortho- and para-H2+ molecules is investigated and compared to the results where such a contribution is disregarded. An analysis of possible propensity rules that may predict the relative probabilities of inelastic events involving rotational state-changing is also carried out, together with the corresponding elastic cross sections from several initial rotational states. Temperature-dependent rotationally inelastic rates are then computed and discussed in terms of relative state-changing collisional efficiency under trap conditions. The results provide the essential input data for modeling different aspects of the experimental setups which can finally produce internally cold molecular ions interacting with a buffer gas.

Regulation of reserve mobilisation in sunflower during late seedling establishment in continuous darkness.

Reserve mobilisation, metabolite partitioning and reserve-degrading enzyme activity were studied in sunflower seedlings cultivated in vitro under a 12-h photoperiod or in the dark to investigate the involvement of source-sink relation and carbon starvation in the regulation of reserve mobilisation under continuous darkness. Reserves, metabolites and enzyme activity were determined with standard spectrophotometric methods. At the first 24 h of treatment (acclimation phase), darkness did not affect growth, but restricted carbon and nitrogen use, as indicated by sugar and amino acid accumulation in the different seedling parts. After 5 days of treatment (survival phase), extended darkness limited growth and retarded storage lipid mobilisation due to carbon starvation, as evidenced by the depletion of carbohydrates in cotyledons and hypocotyl, as well as the consumption of amino acids in hypocotyls and roots. Alterations in the source-sink relationship might have been a response to prolonged darkness, instead of a mechanism used to regulate reserve mobilisation, as these alterations cannot be associated with negative feedback mediated by metabolite accumulation. Storage lipid degradation depends, at least in part, on mechanisms that co-ordinately regulate the activities of lipases and isocitrate lyase. Taking these results together, it is possible that reserve mobilisation in sunflower seedlings cultivated in the dark might be regulated by mechanisms that perceive the absence of light and predict carbon starvation, adjusting reserve use according to future energy demands to allow, at least in the short term, seedling survival.

Gingival crevicular fluid levels of protease-activated receptors type 1 and type 2 in diabetic patients with periodontitis.

BACKGROUND AND OBJECTIVE: Protease activated receptor type 1 (PAR1 ) seems to play a role in periodontal repair, while PAR2 is associated with periodontal inflammation. As diabetes is a known risk factor for periodontal disease, the aim of this study was to evaluate the influence of type 2 diabetes on PAR1 and PAR2 mRNA expression in the gingival crevicular fluid of patients with chronic periodontitis before and after non-surgical periodontal treatment. MATERIAL AND METHODS: Gingival crevicular fluid samples and clinical parameters consisting of measuring probing depth, clinical attachment level, bleeding on probing and plaque index were collected from systemically healthy patients and patients with type 2 diabetes and chronic periodontitis, at baseline and after non-surgical periodontal therapy. PAR1 and PAR2 , as well as the presence of the proteases RgpB gingipain and neutrophil proteinase-3 were assessed by quantitative polymerase chain reaction in the gingival crevicular fluid. RESULTS: The periodontal clinical parameters significantly improved after periodontal therapy (p < 0.01). Diabetes led to increased expression of PAR1 in gingival crevicular fluid, and in the presence of chronic periodontitis, it significantly decreased the expression of PAR1 and PAR2 (p < 0.05). Moreover, non-surgical periodontal treatment in diabetics resulted in increased expression of PAR1 and PAR2 (p < 0.05), and decreased expression of RgpB gingipain and proteinase-3 (p < 0.05). CONCLUSION: The present data demonstrated that diabetes was associated with an altered expression of PAR1 and PAR2 in the gingival crevicular fluid cells of subjects with chronic periodontitis. Future studies are necessary to elucidate the effects of PAR1 upregulation in periodontally healthy sites and PAR2 downregulation in chronic periodontitis sites on the increased susceptibility and severity of periodontitis in diabetes.

Does previous chemotherapy-induced nausea and vomiting predict postoperative nausea and vomiting?

BACKGROUND: Postoperative nausea and vomiting (PONV) remains a problem in the postoperative period. Previous PONV in oncology patients has recently been associated with chemotherapy-induced nausea and vomiting (CINV). We assessed if CINV could improve Apfel's heuristic for predicting PONV. METHODS: We conducted a retrospective study of 1500 consecutive patients undergoing intermediate or major cancer surgery between April and July 2011. PONV was assessed in the first postoperative day during post-anaesthesia care. The assigned anaesthetist completed an electronic medical record with all of the studied variables. Multiple logistic regression analyses were performed to assess whether any of the variables could add predictive ability to Apfel's tallying heuristic, and receiver operating characteristic (ROC) curves were modelled. The areas under the curve (AUC) were used to compare the model's discriminating ability for predicting patients who vomited from those who did not vomit. RESULTS: The overall incidence of PONV was 26%. Multiple logistic regressions identified two independent predictors for PONV (odds ratio; 95% CI), Apfel's score (1.78; 1.23-2.63) and previous chemotherapy-induced vomiting (3.15; 1.71-5.9), Hosmer-Lemeshow's P < 0.0001. Previous CINV was the most significant predictor to be added to Apfel's heuristic in this population. CONCLUSIONS: A history of chemotherapy-induced nausea vomiting was a strong predictor for PONV and should be investigated as an added risk factor for PONV in the preoperative period of oncology surgery in prospective studies.

Inhaled beclomethasone in pregnant asthmatic women--a systematic review.

The aim of this study was to systematically review the safety and efficacy of inhaled beclomethasone for asthma treatment in pregnant women. We performed a systematic review in Medline, LILACS and SciELO electronic databases in December 2012. A total of 3433 articles were found by using the keywords asthma, pregnancy and beclomethasone. Among these, 1666 were from Medline, via PubMed, and 1767 were from LILACS and SciELO. Nine of these articles were selected. Only one paper suggested an increased foetal risk for congenital malformations, and one other for offspring endocrine and metabolic disturbances. Data are mostly reassuring, supporting the use of glucocorticoid inhalants during pregnancy, and we found no evidence of inferiority in relation to efficacy and safety of beclomethasone compared to other drugs used in pregnant asthmatic women.

MSX1 gene polymorphisms in non-syndromic cleft lip and/or palate.

OBJECTIVE: The aim of this study was to investigate the contribution of 6 polymorphic variants of the MSX1 gene in non-syndromic cleft lip and/or palate (NSCL/P). METHODS: Three hundred and fifty-eight individuals (158 NSCL/P cases and 200 controls) were genotyped by TaqMan allelic discrimination using predesigned SNP assays. Statistical analyses were conducted using the software spss 15.0 and the r statistical suite. Haplotype block structure and haplotype frequencies were determined using the Haploview. A P-value of 0.05 and confidence interval of 95% were used for all of statistical tests. RESULTS: The patients with non-syndromic cleft lip and/or palate were characterized by similar distribution of MSX1 genotypes and allele in comparison to subjects without oral clefts (P > 0.05). Two haplotype blocks were constructed with polymorphisms of MSX1 gene and haplotypes formed showed a similar frequency in patients with and without oral clefts. CONCLUSIONS: The present study provides no evidence that MSX1 polymorphisms (rs3775261, rs1042484, rs12532, rs6446693, rs4464513 and rs1907998) play a major role in NSCL/P.

Nutritional assessment associated with length of inpatients' hospital stay.

OBJECTIVE: To evaluate the nutritional status of patients on hospital admission, identify the length of hospital stay and identify the parameters of nutritional assessment that are most closely related with the length of stay (LOS). METHODS: A cross-sectional study of 278 hospitalized patients evaluated patients' nutritional status in the 48 hours after admission and their LOS after discharge. Anthropometric and biochemical parameters, related to nutrition status were analyzed, such as: weight, height, arm circumference (AC), waist circumference (WC), triceps skinfold thickness (TST), mild arm muscle circumference (MAMC), albumin (Alb) and hemoglobin (HB). Body mass index (BMI) was used to classify the nutritional status. All the nutritional factors except type of disease, gender and age were associated with LOS. The chi-square, Student-t, Mann-Whitney, Kruskal-Wallis and binary logistic multivariate tests were used in the statistical analyses. RESULTS: The majority of patients was male (53%), elderly (56%) and had neoplasm (19.4%). Undernutrition was higher in the elderly (p < 0.05) and neoplasm patients (p < 0.05), overweight or obese patients were more likely to suffer from cardiovascular diseases (p = 0.001). Average LOS was 14.7 days (± 12.5), longer in neoplasm patients (p < 0.05) and in elderly ones (p < 0.05), and also was 3 times longer in males (p < 0.0001). Among the nutritional parameters, patients with AC under 25 cm had higher LOS (p < 0.05), but only in women could it be considered a marker, increasing LOS 2.8 times. BMI less than 20 kg/m(2) increased LOS 2.1 times, and biochemical data (Alb and HB) do not contribute. In the multivariate analyses, male gender and TST depletion were the significant factors, which together best explained the lengths of hospital stay. CONCLUSION: LOS was associated with disease, gender, age and nutritional status. We can highlight two anthropometric analyses: first, AC can be used in women as a marker of longer LOS and second TST is the best overall predictor of longer hospital stay.

Importance of dynamic culture for evaluating osteoblast activity on dense silicon-substituted hydroxyapatite.

This paper reports an investigation on human osteoblast-like cells (SaOs-2) seeded onto pure hydroxyapatite (HA) and silicon-substituted HA (SiHA) tablets under static and dynamic culture conditions. The biological characterizations were conducted in classical static conditions in multi-wells plates, and in a perfusion bioreactor that permits continuous circulation of culture medium at 2 mL/h. The morphology, proliferation and differentiation of osteoblastic cells were examined for the two types of samples in the both culture conditions after 1, 3 and 8 days. Under dynamic conditions, cells cultured on SiHA surfaces showed a faster adhesion process and the formation of longer and thinner focal adhesions than in static conditions. The number of cells grown onto both ceramic surfaces was higher in dynamic conditions when compared with static conditions. Moreover, a higher activity of alkaline phosphatase was found for cells seeded under dynamic conditions. Our findings suggest that the application of perfusion culture system on cells cultured on dense substrates is valuable for predicting in vivo behaviour of cells on biomaterials.

Panbiogeographical analysis of the shark genus Rhizoprionodon (Chondrichthyes, Carcharhiniformes, Carcharhinidae).

The distributional patterns of the seven species of Rhizoprionodon were analysed using the panbiogeographical method of track analysis. The individual tracks of Rhizoprionodon suggest that the genus is mainly an Indian-Atlantic Ocean group. Five generalized tracks were found: (1) Caribbean, defined by R. porosus and R. terraenovae; (2) eastern coast of South America, defined by R. porosus and R. lalandei; (3) Indian Ocean, defined by R. acutus and R. oligolinx; (4) north-western Australia, defined by R. acutus, R. oligolinx and R. taylori; (5) north-north-eastern Australia, defined by R. acutus and R. taylori. Only R. longurio was not included in any generalized track, and its distribution is restricted to the eastern Pacific Ocean. Two biogeographical nodes were found at the intersection of the generalized tracks 1 and 2 (Caribbean Sea) and generalized tracks 4 and 5 (north Australia). The generalized tracks overlap with those found in several unrelated marine taxa. Overall, the generalized tracks are associated with warm currents. The biogeographical nodes found (Caribbean and Australian) are coincident with the global distribution of mangroves.

Surface transformation of silicon-doped hydroxyapatite immersed in culture medium under dynamic and static conditions.

A comparative study of in vitro bioactivity of hydroxyapatite (HA) and silicon-doped hydroxyapatite (SiHA) has been carried out by immersion in a cell culture medium with or without fetal bovine serum during 14 days in static and dynamic conditions. A specific bioreactor was developed for the experiments in dynamic conditions. Ceramic surface transformations were characterized by electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy before and after immersion. The monitoring of calcium, phosphate and proteins in immersion medium was also done during the experiment. The two hydroxyapatite surfaces immersed in cell culture medium under dynamic conditions were found to be more probably covered by a new Mg-enriched Ca-deficient apatite layer than surfaces immersed under static conditions. These results suggest that dynamic procedure and medium with serum macromolecules seem to be more adequate to predict the in vivo activity of bioceramics. Moreover, SiHA presented a higher capacity of protein adsorption.

The genetic architecture of maize flowering time.

Flowering time is a complex trait that controls adaptation of plants to their local environment in the outcrossing species Zea mays (maize). We dissected variation for flowering time with a set of 5000 recombinant inbred lines (maize Nested Association Mapping population, NAM). Nearly a million plants were assayed in eight environments but showed no evidence for any single large-effect quantitative trait loci (QTLs). Instead, we identified evidence for numerous small-effect QTLs shared among families; however, allelic effects differ across founder lines. We identified no individual QTLs at which allelic effects are determined by geographic origin or large effects for epistasis or environmental interactions. Thus, a simple additive model accurately predicts flowering time for maize, in contrast to the genetic architecture observed in the selfing plant species rice and Arabidopsis.

Bioactivation of alumina by surface modification: a possibility for improving the applicability of alumina in bone and oral repair.

OBJECTIVES: In regenerative medicine, surface engineering of bioinert synthetic materials is often required in order to introduce bioactive species that can promote cell adhesion, proliferation, viability and enhanced ECM-secretion functions. The aim of this work is to study cell interaction with alumina-modified surfaces. MATERIAL AND METHODS: In this work, chemical properties of alumina surface were changed by a reaction at the surface of alumina with low molecular weight dicarboxylic acid, which produced carboxyl groups. RESULTS: These carboxyl groups were able to complex with Ca2+ on the surface, forming sites of precipitation for calcium phosphates that make alumina biocompatible, as indicated by cell culture of pre-osteoblasts (MC3T3-E1 cell line). CONCLUSIONS: The procedure presented in this work shows that the insertion of specific functional groups on the surface of alumina increases cell interaction with the surface of alumina. This knowledge can be important in oral science and orthopedics, for the construction of prosthesis.

Genetic and QTL analysis of maize tassel and ear inflorescence architecture.

Maize (Zea mays L.) ear inflorescence architecture is directly relevant to grain yield components, and tassel architecture is relevant to hybrid seed production. The objectives of this study were to (1) determine heritabilities and correlations of a comprehensive set of tassel and ear inflorescence architecture traits in a set of (Illinois Low ProteinxB73) B73 S1 families, (2) identify chromosomal positions of QTL affecting tassel and ear architecture, and (3) identify possible candidate genes associated with these QTL. For tassel traits, the number of detected QTL ranged from one to five, and explained between 6.5 and 35.9% of phenotypic variation. For ear traits, the number of detected QTL ranged from one to nine and phenotypic variation explained by those QTL varied between 7.9 and 53.0%. We detected QTL for tassel architecture traits that required calculation of ratios from measured traits. Some of these calculated traits QTL were detected in regions that did not show QTL for the measured traits, suggesting that calculation of ratios may reveal developmentally relevant patterns of tassel architecture. We detected a QTL on chromosome 7 for tassel branch number near the gene ramosa1 (ra1), which is known to control tassel branch number, making ra1 a candidate gene for tassel branch number. We detected QTL for several traits on chromosomes 6, 8, and 9, where no inflorescence architecture genes have been mapped, thus providing initial information towards new gene discovery for control of inflorescence architecture.

Critical flicker frequency in migraine. A controlled study in patients without prophylactic therapy.

The critical flicker frequencies (CFF) of individuals with migraine with and without aura were determined and compared to those of normal controls. Twenty-six migraine patients, 12 with aura and 14 without aura and 30 healthy controls were included. Migraineurs were tested during a migraine-free period, through both the continuous flicker method (CFM) and the forced choice method (FCM). Migraineurs presented a mean flickering fusion threshold lower than healthy controls with the CFM (40.45 vs. 44.33, respectively; P = 0.019) and with the FCM (34.16 Hz vs. 38.5 Hz, respectively, P = 0.019). Both groups of migraineurs had significantly lower thresholds as compared to controls, migraineurs with aura presenting the lowest thresholds for the fusion of flickering (P = 0.008 and P = 0.0001 with the CFM and the FCM, respectively). Results confirmed and extended previous observations of abnormal flicker fusion thresholds in migraineurs. We hypothesize that this finding might be related to a shorter cortical stimulation silent period.

Headache related to a specific screen flickering frequency band.

The case of a 25-year-old white male, who had migrainous headaches each time he sat in front of his personal computer screen, is described. Changing the screen frequency from 60 to 75 Hz through a Windows command could abolish the headaches. In several surveys, computer screens have been reported to be a migraine trigger. We hypothesize that this environmental trigger may be related to the abnormal flicker fusion thresholds that have been described in migraineurs. It may be that modifying the frequencies of light sources, such as computer screens, could become a non-pharmacological approach to prevent migraine attacks.