Mass Growth Rate Research Articles

Resilience and phenotypic plasticity of Arctic char (Salvelinus alpinus) facing cyclic hypoxia: insights into growth, energy stores and hepatic metabolism.

Arctic char (Salvelinus alpinus) is facing the decline of its southernmost populations due to several factors including rising temperatures and eutrophication. These conditions are also conducive to episodes of cyclic hypoxia, another possible threat to this species. In fact, lack of oxygen and reoxygenation can both have serious consequences on fish as a result of altered ATP balance and an elevated risk of oxidative burst. Thus, fish must adjust their phenotype to survive and equilibrate their energetic budget. However, their energy allocation strategy could imply a reduction in growth which could be deleterious for their fitness. Although the impact of cyclic hypoxia is a major issue for ecosystems and fisheries worldwide, our knowledge on how salmonid deal with high oxygen fluctuations remains limited. Our objective was to characterize the effects of cyclic hypoxia on growth and metabolism in Arctic char. We monitored growth parameters (specific growth rate, condition factor), hepatosomatic and visceral indexes, relative heart mass and hematocrit of Arctic char exposed to 30days of cyclic hypoxia. We also measured the hepatic protein synthesis rate, hepatic triglycerides as well as muscle glucose, glycogen and lactate and quantified hepatic metabolites during this treatment. The first days of cyclic hypoxia slightly reduce growth performance with a downward trend in specific growth rate in mass and condition factor variation compared to the control group. This acute exposure also induced a profound metabolome reorganization in the liver with an alteration of amino acid, carbohydrate and lipid metabolisms. However, fish rebalanced their metabolic activities and successfully maintained their growth and energetic reserves after 1month of cyclic hypoxia. These results demonstrate the impressive ability of Arctic char to cope with its changing environment but also highlight a certain vulnerability of this species during the first days of a cyclic hypoxia event.

Partição de fotoassimilados em plantas de quiabo submetidas a doses de nitrogênio

ABSTRACT Nitrogen (N) is the third nutrient more absorbed by okra. Therefore, an adequate supply of this element is essential for okra growth through the accumulation of dry matter in the leaves, stem, root and fruit. The objective was to evaluate the influence of N doses on growth, photoassimilates partition and yield of okra. The experiment was carried out in a Red-Yellow Argisol. A randomized complete block design with four replicates was used. The treatments consisted of N doses applied as topdressing (0, 60, 120, 240, 360 kg/ha). Samples of plants were held at 60, 75, 90, 105, 120, 135, 150 and 165 DAS for determination of the plant’s dry weight. The plant showed slow growth until 70 days, and after that time, intensified its growth until the end of the cycle. Total dry mass and absolute plant growth rate increased with increasing N availability, reaching the maximum marketable fruit yield of 10,665 kg/ha with 346 kg/ha N. The growth and partition of photoassimilates among the organs of the okra plant ‘Santa Cruz’ are altered with increasing nitrogen availability applied in topdressing.

“Growing fibroadenoma”: Are there clinical and pathological features predicting a phyllodes tumor on surgical excision?

In cases of growth of FA on imaging, core needle biopsies (CNB) are often performed to rule out phyllodes tumor (PT). We aim to focus on “growing FAs” and to identify clinical and histopathologic features that are likely to predict a PT on excision. Thirty-four FAs with radiologic documentation of growth were included. Various clinical and pathological features such as age, body mass index (BMI), lesion size, and growth rate were recorded. On excision, 17 cases (50 %) were FAs, whereas 16 (47 %) were re-classified as benign PT despite only 19 % being suspicious for PT on CNB. PT patients were older (mean age 42.6) than those with FAs (mean age 28.2), p = 0.0002. All false negative cases demonstrated intracanalicular growth. Mitotic rate was the most significant histologic feature in PT on excision compared to others, such as lesion circumscription and stromal cellularity. Recognition and careful counting of mitotic rate, especially with intracanalicular patterns in growing FAs, can potentially prevent missing a PT on CNB. In patients with “growing FAs” who are ≥40 years of age, excision may be recommended due to the high likelihood of PT diagnosis on excision and high false negative rate on CNB.

Fruit growth, carbon allocation, and related enzymes in tomato under different irrigation and potassium application regimes

AbstractBackgroundThe increasing concentration of atmospheric CO2 not only affects the growing environment of crops but also aggravates the global greenhouse effect and further aggravates the problem of water shortage. The combined effect of water deficit and potassium (K) application has not been widely studied.AimsA pot experiment was conducted to investigate the effect of deficit irrigation (DI) and K application at different growth stages on carbon allocation and enzyme activities related to sugar metabolism.MethodsTomatoes were transplanted and planted on April 26, 2017 and harvested on August 15, 2017. Four irrigation regimes were implemented with two water levels (full irrigation‐W and DI‐W/2) in different growth stages, and each water treatment was equally divided into two subgroups: with K (K1) and without K (K0). Fruits from the first to fourth trusses of the tomato plants were sampled. Tomato growth, carbon allocation, and related enzyme activities were measured.ResultsThe fresh weight (FW), dry weight, and relative growth rate of dry mass were sensitive to irrigation amount under K fertilization, enhancing the promotion effect of irrigation on fruit. Meanwhile, carbon allocation was sensitive to irrigation amount under K regime. Sucrose synthase (SuSy), acid invertase (AI), and sucrose phosphate synthase (SPS) were also highly sensitive to irrigation amount under K application condition. Starch phosphorylase displayed a quadratic parabola for irrigation amount, and adenosine diphosphate glucose pyrophosphorylase (AGPase) was highly sensitive to irrigation amount without K fertilization. Carbon in the form of other carbohydrates, carbon in the form of soluble sugar (Csol), and fruit water content were the factors that had the greatest influence on the principal components. Classification by K‐means algorithm and canonical correlation analysis showed that FW, fructose, sucrose, and starch could be used as significant indicators of the dry matter components of the fruit for the treatment without K. In the case of K regime, SuSy, AGPase, AI, and Csol could be used as a significant indicator of the correlation analysis of carbon metabolism activity.ConclusionsThe factors related to the improvement of fruit quality and carbon allocation by deficient irrigation and K application were explored. Water stress changed the distribution of photosynthetic carbon between starch and soluble sugar. K application further changed the balance between soluble sugars and other compounds. In particular, it significantly increased the carbon content of soluble sugars and decreased that of other compounds. AI and SuSy are key enzymes affecting carbon metabolism under water‐deficient conditions.

SYNERGISTIC EFFECT OF HONEY AND LEMON JUICE-ENRICHED MULBERRY DIETS ON THE GROWTH OF SILKWORM, BOMBYX MORI DURING METAMORPHOSIS

Synergistic impact of honey and lemon juice-enriched mulberry diets on the growth of Bombyx mori was studied. The body size progressively increased during larval stage, but declined during pupal and adult stages. The nutrient diets promoted larval growth and positively modulated pupal and adult growth. The larval growth curves are typical Gompertz trajectories that reected the growth promoting nature of honey and lemon juice. The log-based growth curves were used to derive critical larval body size determinants that control molting and metamorphosis. The nutrient diets improved critical body size determinants without affecting their time schedules. The compound periodical growth rates showed instar-specic and stage-specic variations. The size specic growth rates in body mass, length and perimeter dimensions indicated the prevalence of an effective mass management mechanism as dened in the Hutchinson's investment principle. The silkworm recorded either higher or lower growth ratios indicating deviation from the Dyar's constancy rule.

Changes in the structure of synaptic intercellular contacts in focal brain lesions

Purpose: to evaluate changes in the structure of synaptic contacts in various types of focal brain pathology. Materials and methods. The results of treatment of 40 cases of supratentorial focal lesions of the brain (FLB) were retrospectively evaluated. The cases are divided into groups: 30 gliomas of various degrees of malignancy and 5 consequences of TBI, 5 epilepsy. All patients underwent surgical interventions. The synaptic plasticity of axo-dendritic and axo-spiny asymmetric synapses of neurons of the VI-VII layers of the frontotemporal cortex was studied by electron microscopy. Morphometric analysis was carried out on a computer image analyzer САИ-01АВН using the software "Kappa opto-electronics GmbH" using the STATISTICA 7 program package. The results. It was established that the density of synapses decreased in glioblastomas (GB) and craniocerebral injury (ССІ). Qualitative changes demonstrate the plasticity of architectonics of synapse, in particular due to the increase in the number of perforated synaptic contacts. Maximum thickening and diffuse stratification of the postsynaptic seal indicates a violation of the functional capacity of the postsynaptic component of the contacts. A decrease in the number of synaptic vesicles was revealed in ССІ and GB, with their rearrangement, which is probably a manifestation of synaptic dysfunction. The latter proves the irreversibility of destructive local changes and is unfavorable criterion. The risk of the formation of destructive-degenerative changes in the synaptic apparatus is 7.64 times higher in DA, 3.17 times higher in GB, and 17.31 times higher in ССІ compared to cases of epilepsy, with GB significantly increases by 13.5 times compared to DA. Therefore, the assessment of the structural features of neuroplasticity should take into account the morphogenesis of the BM in comparison with clinical data Conclusions. In the zones of invasive growth of gliomas of various degrees of malignancy and in ССІ and epilepsy, the indicators of synaptic plasticity differ statistically significantly. The density of placement of synapses is lower in GB and ССІ. The probability of non-reversibility of destructive-degenerative changes of synapses according to the number of SVs in FLB correlates with the degree of glioma differentiation with a sensitivity of 81.0% and a specificity of 76.0%. According to the structural changes of synaptic connections in tumors, probable differences between the variants have been proven: GB and DA, the sensitivity of the discriminant model is 85.0%, the specificity is 74.0%, which is an indirect evidence of the growth rate of the tumor mass and its destructive effect on the surrounding brain matter. The obtained results are important in assessing the prognosis of the further course of the disease.

An Edible and Quick-Dissolving Film from Cassia Gum and Ethyl Cellulose with Improved Moisture Barrier for Packaging Dried Vegetables.

A quick-dissolving edible film was made from cassia gum (CG) incorporated with ethyl cellulose (EC). Mechanical results show that addition of 5% EC based on CG gave rise to the highest tensile strength (TS) of the composite film. Scanning electron microscopy revealed that excess addition of EC slightly decreased the homogeneousness of films. Fourier transform infrared spectroscopy showed that the compatibility between CG and EC was good and the incorporation of EC changed the original interaction of molecules by forming hydrogen bonds with CG. Although film light transmittance decreased, it is transparent enough for packaging. The film water vapour barrier property improved dramatically by blending CG and EC, although they showed dissolution rates over 80% in boiling water after 5 min. The dried carrot cube packaged by CG-EC films showed lower mass growth rates in 53% RH. Therefore, the film presents a potential application in packaging of dried vegetables in convenience foods.

Effects of chemical potential differences on methane hydrate formation kinetics

To underpin the increasing interest in practical applications of gas hydrates, for gas storage and separation for instance, the formation and growth of hydrates at liquid-gas interfaces are of fundamental importance. Although the thermodynamics of hydrate formation has been widely studied and is well understood, the kinetics of these processes is not well characterised. In this work, a high-pressure, low-temperature stirred reactor was used to conduct hydrate formation kinetic studies in a temperature range from 276.5 to 283.5 K and a pressure range from 5 to 10.5 MPa, with a special focus on 1) the impact of agitation conditions on the available water-gas interfacial surface area for mass transfer and growth rate during hydrate formation, and 2) the effect of the chemical potential driving force on the formation rate. Five hydrate growth regimes were identified, with varying degrees of gas mass transfer control across the gas-water interface depending on the extent to which hydrate layers built up at this interface, gas needed to move through solid hydrate layers, and the extent to which the gas was entrained within the water phase. The formation rate in the initial linear growth regime, before the onset of solid hydrate gas mass transfer effects, was found to depend in an essentially exponential manner on the chemical potential difference from the equilibrium state. Semi-empirical models related to Arrhenius-type kinetic models were used to correlate the data, the best of which reproduced the formation rates from the chemical potential differences to within ± 5 %. The approach has general applicability to help determine the balance between kinetic and thermodynamic factors in identifying the optimum pressure-temperature conditions for processes for gas storage, gas separation and other hydrate applications.

SDSS-IV MaNGA: Cannibalism Caught in the Act—On the Frequency of Occurrence of Multiple Cores in Brightest Cluster Galaxies

Although it is generally accepted that massive galaxies form in a two-phased fashion, beginning with a rapid mass buildup through intense starburst activities followed by primarily dry mergers that mainly deposit stellar mass at outskirts, the late time stellar mass growth of brightest cluster galaxies (BCGs), the most massive galaxies in the universe, is still not well understood. Several independent measurements have indicated a slower mass growth rate than predictions from theoretical models. We attempt to resolve the discrepancy by measuring the frequency of BCGs with multiple cores, which serve as a proxy of the merger rates in the central region and facilitate a more direct comparison with theoretical predictions. Using 79 BCGs at z = 0.06–0.15 with integral field spectroscopic data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) project, we obtain a multiple-core fraction of 0.11 ± 0.04 at z ≈ 0.1 within an 18 kpc radius from the center, which is comparable to the value of 0.08 ± 0.04 derived from mock observations of 218 simulated BCGs from the cosmological hydrodynamical simulation IllustrisTNG. We find that most cores that appear close to the BCGs from imaging data turn out to be physically associated systems. Anchoring on the similarity in the multiple-core frequency between the MaNGA and IllustrisTNG, we discuss the mass growth rate of BCGs over the past 4.5 Gyr.

DNA G-quadruplex structure participates in regulation of lipid metabolism through acyl-CoA binding protein.

G-quadruplex structure (G4) is a type of DNA secondary structure that widely exists in the genomes of many organisms. G4s are believed to participate in multiple biological processes. Acyl-CoA binding protein (ACBP), a ubiquitously expressed and highly conserved protein in eukaryotic cells, plays important roles in lipid metabolism by transporting and protecting acyl-CoA esters. Here, we report the functional identification of a G4 in the promoter of the ACBP gene in silkworm and human cancer cells. We found that G4 exists as a conserved element in the promoters of ACBP genes in invertebrates and vertebrates. The BmACBP G4 bound with G4-binding protein LARK regulated BmACBP transcription, which was blocked by the G4 stabilizer pyridostatin (PDS) and G4 antisense oligonucleotides. PDS treatment with fifth instar silkworm larvae decreased the BmACBP expression and triacylglycerides (TAG) level, resulting in reductions in fat body mass, body size and weight and growth and metamorphic rates. PDS treatment and knocking out of the HsACBP G4 in human hepatic adenocarcinoma HepG2 cells inhibited the expression of HsACBP and decreased the TAG level and cell proliferation. Altogether, our findings suggest that G4 of the ACBP genes is involved in regulation of lipid metabolism processes in invertebrates and vertebrates.

Long-term observation of the effect of atlantoaxial fusion on the growth and development of children's cervical spine

Objective: To explore the effect of atlantoaxial fusion on the growth and development of children's cervical spine. Methods: The clinical data of 12 children with atlantoaxial dislocation who underwent posterior atlantoaxial fusion at Department of Orthopaedics,the 909th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army from June 2002 to September 2013 were retrospective analyzed. There were 7 males and 5 females,with age of (8.1±3.1)years (range:3 to 13 years).Nine cases were traumatic and 3 cases were congenital malformations,1 of the children had Down syndrome. All children underwent posterior atlantoaxial fusion. Furthermore,the information of the height and anteroposterior width of the cervical vertebral bodies and vertical growth rate of the fusion mass were collected from all patients immediately postoperatively and during the follow-up.The range of motion in cervical spine were collected preoperatively and during follow-up period. Data were compared using independent sample t test, paired sample t test and repeated-measurement. Results: All 12 children had regular follow-up within (122.4±25.3)months(range:65 to 163 months). The height and anteroposterior width of the cervical vertebral bodies were similar to these results with those in published reports of growth in normal children of the same age(all P<0.01). At the last follow-up,atlantoaxial fusion of 11 cases had substantial growth (vertical growth rate of the fusion mass:11 cases ≥10%, 1 case <10%);the range of motion in cervical spine was close to the normal level (flexion(55.2±5.0)°,extension (65.3±4.9)°,left bending (41.7±4.5)°,right bending (42.4±4.4)°,left rotation (66.4±5.6)°,right rotation (68.5±5.8)°). Conclusions: Atlantoaxial fusion surgery is satisfactory in the treatment of pediatric atlantoaxial dislocation.During the follow-up,the growth and development of the cervical spine is close to that of normal children of the same age.In long-term observation,it has been found that the operation has no negative effect on the growth and development of the children's cervical spine.

Co-depositing polyvinylamine and dopamine to enhance membrane performance for concentration of KAc solutions via sweeping air pervaporation

Polydopamine (PDA) has been used as a tool for engineering surfaces due to its good adhesive characteristics onto various surfaces and abundant functional groups for further improvement. However, its weak hydrophilicity and long term stability in an alkaline environment were a concern for membrane applications. To address the issues, we proposed to use polyvinylamine (PVAm) as a co-depositant with dopamine to fabricate thin film composite (TFC) membranes in order to take advantage of the covalent bonding between polydopamine (PDA) and PVAm and the adhesive properties of PDA oligomers. The membranes were investigated for concentrating KAc solutions via sweeping air pervapoation. It was shown that both the hydrophilicity and stability of the membrane were improved by incorporating PVAm into the membrane during the coating/deposition process. It was shown that a PVAm content of 20–30 wt% (solvent free basis) in the PVAm/dopamine depositing solution (i.e., PVAm/dopamine ratio in the range of 2:8 to 3:7) was appropriate for fabricating TFC pervaporation membranes for concentrating aqueous KAc concentrations. At a high salt concentration of 70 wt% in the feed solution, the membrane showed a water flux of 1.2–1.4 kg/m2.h and essentially a complete retention of the salt when tested over a period of over 200 h. The membranes were characterized in terms of surface hydrophilicity, permeance and activation energy for water permeation. In addition, the mass growth rate of the membrane skin layer during membrane buildup was determined as well to provide an insight into the general behavior of dopamine adhesion and polymerization in surface engineering.

Study on the Dynamic Splitting Mechanical Properties of Annular Sandstone Specimens with Temperature–Water Coupling in a Coal Mine

With the gradual deepening of mine excavation depth, the strong disturbance of deep strata becomes more and more obvious. Rock’s failure under blasting mainly depends on its dynamic tensile strength. The changes in rock’s dynamic properties are obviously affected by temperature and water. In order to study the dynamic tensile properties of annular sandstone specimens under the influence of temperature and water, deep sandstone was drilled, followed by water bath tests at eight temperatures (25~95 °C). It can be seen from the analysis of test results that the mass and volume growth rates of the annular and the intact sandstone specimens first increased and then decreased, while the density growth rate first decreased and then increased. The mass and volume growth rates of the annular sandstone specimens were smaller, but the density growth rate was larger. Because of the increase in water temperature, the dynamic compressive strength first increased and then decreased. The dynamic tensile strength of the annular sandstone specimen was lower. The average strain rate and peak strain also showed a quadratic function relationship of first decreasing and then increasing with the increase in water temperature. The average strain rate of the annular sandstone specimen was smaller, but the peak value changed greatly. The Brazilian disc validity condition is applicable to two failure conditions of sandstone specimens. Through XRD and SEM analysis, we found that the changes in the dynamic properties of sandstone specimens were not due to their own material composition, but to the damage to their structure caused by the temperature–water coupling effect.

Characteristics of potato (Solanum tuberosum) genotypes for resistance to abiotic environmental stress factors

The optimal variety choice for each specific region is one of the main factors influencing the productivity increase and improving the quality of the table and seed potato. It is necessary to cultivate varieties that combine the maximum adaptability to abiotic environmental factors and high field resistance or immunity to various phytopathogens. Therefore, the present study aimed to identify varieties and hybrid material of potatoes of various genetic and geographical origin with high resistance to high air temperatures and insufficient moisture. The research was conducted during April and May 2021 at the laboratory of biotechnology of agricultural plants of the Samara Scientific Research Agriculture Institute named after N. M. Tulaykov - branch of the SamSC RAS, Bezenchuk vil., Russia. The maximum average productivity was characterized by medium-early varieties Krasa Meschery (32.3 t/ha), Debut (27.8 t/ha) and Sudarynya (26.2 t/ha) and medium-ripe varieties Utro (29.4 t/ha), Siversky (32.2 t/ha) and Alaska (31.0 t/ha). It is shown that in conditions of arid climate, medium-early and medium-ripe potato varieties with genotypes of intensive and neutral type have an advantage in yield over varieties of other varieties. The interrelation of morphological features of the aboveground part of the potato plant with the yield of tubers is established. It is shown that in conditions of high air temperature and insufficient humidification, varieties with a high rate of green mass growth in the period from 50 to 60 days from planting and with a high number of stems per plant can have an advantage. he obtained results can be used in breeding work for heat resistance and drought resistance for a quick preliminary assessment of a significant amount of hybrid potato material at the initial stages of the breeding process, as well as one of the stages of a comprehensive study of new varieties.

Effect of initial curing period on the behavior of mortar under sulfate attack

The infrastructures in the ocean and salt lake areas are usually subjected to sulfate attack shortly after casting. But the influence of early exposure is unclear yet. This study aims to evaluate the influence of early exposure on mortar properties under sulfate attack and to identify the degradation mechanism under this condition. The mortar specimens with different initial curing periods (1, 3, 7, 14 and 28 days) were immersed in 10% Na2SO4 solution for equal time periods (60, 90, 150, 240 and 360 days). Evaluation of the influence of early exposure on mortar behavior under sulfate attack was based on changes in physical properties and mechanical strengths. The degradation mechanism of the mortar specimens was analyzed by X-ray diffraction (XRD), and scanning electron microscopy (SEM) with energy-dispersive spectrometry (EDS). The results showed that the shortening of the initial curing period led to more sulfate ions penetrating into the specimen, resulting in more serious surface spalling, higher expansion rate and mass growth rate, lower mechanical strength. Microscopic images showed that the cement matrix of the early exposed specimen was much looser. In addition, the relationships between compressive strength and other mechanical strengths considering the initial curing period were established and fitted reasonably well with other data sources.

Preparing Mg(OH)2-based materials by electro-deposition method from magnesium- and calcium-rich brine simulant

Pollution to the ocean caused by the disposal of reject brine is a serious environmental concern. Recycling the ions in reject brine for materials manufacturing can mitigate this environmental burden and create new value streams. This paper presents a way of preparing Mg(OH)2-based building materials from magnesium- and calcium-rich solutions through electro-deposition. The validity of this method in two scenarios, namely brine simulant and seawater simulant, was assessed by comparing the efficiency of deposition; and the properties of the deposits were investigated by X-ray diffractometry (XRD), thermo-gravimetric (TG), mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM), and atomic force microscope (AFM). It was found that a Mg(OH)2-based material mixed with CaCO3 and Ca(OH)2 could be electrically deposited on the surface of the cathode. The mass growth rate, mechanical performance, and compactness of the deposits prepared from the brine simulant were better relative to those of the deposits prepared from the simulated seawater. On the micro-scale, the particles grown from the brine simulant showed a higher packing density and smaller size, which could have a positive effect on the mechanical property of the deposits. Overall, magnesium- and calcium-rich brines can be more promising for preparing Mg(OH)2-based building materials relative to seawater.

Декарбонизация выхлопных газов установок производства водорода и использование диоксида углерода в тепличном хозяйстве

The influence of carbon dioxide on the environment, including the impact on humans and plants, is considered.22The dependence of the growth rate of the green mass of plants on the concentration of CO was revealed.The methods of carbon dioxide capture possible for use at refineries are considered. The most optimal method of carbon dioxide capture was selected, sorbents for this process were also selected based on their selectivitywith respect to carbon dioxide. The method of using carbon dioxide in greenhouses is considered, and the economic effect of the introduction of this technology into production is also calculated.

Growth, leaf gas exchange and mycorrhizal colonization of three medicinal species submitted to different irradiance levels

ABSTRACT: This study o evaluated growth, leaf gas exchange and arbuscular mycorrhizal fungi root colonization in three medicinal plant species under different irradiance intensities. Fridericia chica (Bonpl.) L.G.Lohmann, Mikania laevigata Sch.Bip. ex Baker and Varronia curassavica Jacq. were propagated by cutting and cultivated for 120 days in artificially shaded environments using black shade-type screens, obtaining four irradiance levels: 100%, 70%, 50% and 30%. The experimental design was completely randomized in a 3 x 4 factorial scheme (three plant species and four irradiation levels) with seven replicates. The three medicinal species showed higher liquid assimilation, mass growth and arbuscular mycorrhizal fungi root colonization rates when exposed to environments with 70% light availability. In relation to physiological responses, V. curassavica presented higher photosynthetic rate, stomatal conductance and transpiration when submitted to 70% irradiance, being able to be cultivated in more open environments with higher irradiation levels. Conversely F. chica and M. laevigata presented shade tolerance characteristics. At the initial growth phase, the results obtained can be used as indicators to recommend the ideal cultivation environment for these species in agroforestry systems.

Influence of drug properties on loadings and release kinetics of drugs from silica aerogels loaded in supercritical CO2

The present work investigates influence of drug properties on drug loadings in silica aerogels from supercritical carbon dioxide (scCO2) and their release. Benzoic acid (BA) and fenofibrate (FF) with different molecular mass and solubilities in water and scCO2 are selected as drugs for comparison of loadings by two modes: adsorption and adsorption plus precipitation, in pores and on outer surface of aerogels. Modeling of precipitation during depressurization predicts lower nucleation rates for FF due to its higher molecular mass and higher growth rates due to its higher supersaturation compared to BA. Higher drug solubility in scCO2 facilitates higher loadings by adsorption and precipitation. Experiments confirm that larger amounts of FF adsorb and precipitate compared to BA; precipitation occurs mostly on the outer surface of aerogels, in much shorter time than adsorption. The precipitated drugs are amorphous and release much faster than crystalline forms, though FF releases slower than BA.

Can morpho-physiological responses to natural light conditions in Cybistax antisyphilitica (Mart.) Mart. explain its widespread occurrence in Brazilian Savannas?

Cybistax antisyphilitica (Bignoniaceae) is extensively distributed in the Cerrado biome, from typical savannas to forest formations. In these areas, light varies widely in both time and space. The aim of this study was to investigate the initial growth and physiological responses of potted C. antisyphilitica seedlings to natural light conditions. To this end, we cultivated one group of seedlings under full sunlight (FS), a second group under a small gap with medium transmittance (MT) and a third group under canopy shade with low transmittance (LT), in an urban fragment of a tropical semideciduous forest. The daily course of chlorophyll a fluorescence was measured at the beginning, middle and end of the dry season. Also, at the end of the experiment, measurements of leaf gas exchange and growth were carried out. Dynamic photoinhibition was found in seedlings under FS. The photosynthetic rates, stomatal conductance and transpiration rates were higher under FS compared to seedlings under LT conditions. Overall, the stem diameter, the dry mass of leaves and stem, total dry mass and relative growth rate were higher in plants under FS and MT than plants under LT. Cybistax antisyphilitica allocated less biomass to stems and leaves and more to the roots, independent of growth conditions. The plasticity at leaf level suggests that C. antisyphilitica can exploit the heterogenous light environment of the semideciduous forest, but the massive development of the roots can contribute to its tolerance to dry periods typical of the Cerrado biome.