24-Epibrassinolide alleviates drought effects in young Carapa guianensis plants, improving the hydraulic safety margin, gas exchange and antioxidant defence.

Climate change is increasing the frequency of extreme events such as droughts, limiting plant growth and productivity. Exogenous application of plant growth regulators, such as 24-epibrassinolide (EBR), might be a solution as this molecule is organic, eco-friendly, and biodegradable. This is the first research to examine possible roles of EBR on the hydraulic safety margin, physiological behaviour, and metabolism in Carapa guianensis Aubl. (Meliaceae) exposed to drought. C. guianensis is a widely distributed tree in tropical forests of the Amazon. The objective was to determine whether EBR can improve tolerance to water deficit in young C. guianensis by measuring hydraulic traits, nutritional, biochemical and physiological responses, and biomass. The experiment had four randomized treatments: two water conditions (control and water deficit) and two concentrations of EBR (0 and 100 nM EBR). EBR increased the water potential and hydraulic safety margin, increased CO2 fixation, and improved stomatal performance. EBR also stimulated antioxidant defences (SOD, CAT, APX, and POX). Overall, tretreatment with EBR improved drought tolerance of young C. guianensis plants.

Ionic homeostasis and redox metabolism upregulated by 24-epibrassinolide are crucial for mitigating nickel excess in soybean plants, enhancing photosystem II efficiency and biomass.

Nickel (Ni) excess often generates oxidative stress in chloroplasts, causing redox imbalance, membrane damage and negative impacts on biomass. 24-Epibrassinolide (EBR) is a plant growth regulator of great interest to the scientific community because it is a natural molecule extracted from plants, is biodegradable and environmentally friendly. This study aimed to determine whether EBR can improve ionic homeostasis, antioxidant enzymes, PSII efficiency and biomass by evaluating nutritional, physiological, biochemical and morphological responses of soybean plants subjected to Ni excess. The experiment used four randomized treatments, with two Ni concentrations (0 and 200 µm Ni, described as -Ni2+ and +Ni2+ , respectively) and two concentrations of EBR (0 and 100 nm EBR, described as -EBR and +EBR, respectively). In general, Ni had deleterious effects on chlorophyll fluorescence and gas exchange. In contrast, EBR enhanced the effective quantum yield of PSII photochemistry (15%) and electron transport rate (19%) due to upregulation of SOD, CAT, APX and POX. Exogenous EBR application promoted significant increases in biomass, and these results were explained by improved nutrient content and ionic homeostasis, as demonstrated by increased Ca2+ /Ni2+ , Mg2+ /Ni+2 and Mn2+ /Ni2+ ratios.

Comment on "Uncommon structural and bonding properties in Ag16B4O10" by A. Kovalevskiy, C. Yin, J. Nuss, U. Wedig, and M. Jansen, Chem. Sci., 2020, 11, 962.

A thorough systematic study of the Electron Localization Function (ELF) in fcc silver metal, the deficient vacant-type Ag16□4 structure, and the Ag16B4O10 title compound of the Chem. Sci., 2020, 11, 962 edge article leads to a further understanding of the sub-valent characteristics of silver in the silver borate compound. By visualizing the process in three consecutive steps, (fcc)eq-Ag → (fcc)ex-Ag → Ag16□4 → Ag16B4O10, the electron reduction of Ag atoms can be traced to be due to (i) the expansion (ex) of the host metallic array from its equilibrium (eq) geometry and (ii) the vacancy creation and subsequent insertion of guest borate clusters. Our ELF analysis also allows us to identify to what extent metallic features remain in the title compound, providing an alternative explanation of why Ag16B4O10 is not a conductor whereas pure silver is.

Temperature and pressure-induced strains in anhydrous iron trifluoride polymorphs.

Various structural configurations of iron trifluoride appear at the nanoscale and macroscopic size, either in the amorphous or crystalline state. The specific atomic organization in these structures crucially alters the performance of FeF3 as an effective cathode in Li-ion batteries. Our detailed first-principles computational simulations examine the structural strains induced by temperature and stress on the four anhydrous polymorphs observed so far in FeF3 at ambient pressure. A wealth of data covering previous experimental results on their equilibrium structures and extending their characterization with new static and isothermal equations of state is provided. We inform on how porous apertures associated with the six-octahedra rings of the HTB and pyrochlore phases are modified under compressive and expansive strains. A quasi-auxetic behavior at low pressures for the ground state rhombohedral phase is detected, which is in concordance with its anomalous structural anisotropy. In contrast with the effect of temperature, this structure undergoes under negative pressure phase transitions to the other three polymorphs, indicating potential conditions where low-density FeF3 could show a better performance in technological applications.

Controlling the off-center positions of anions through thermodynamics and kinetics in flexible perovskite-like materials.

Due to the network flexibility of their BX3 sub-lattice, a manifold of polymorphs with potential multiferroic applications can be found in perovskite-like ABX3 materials under different pressure and temperature conditions. The potential energy surface of these compounds usually presents equivalent off-center positions of anions connected by low energetic barriers. This feature facilitates a competition between the thermodynamic and kinetic control of the transitions from low to high symmetry structures, and explains the relationship between the rich polymorphism and network flexibility. In the rhombohedral phase of iron trifluoride, our first-principles electronic structure and phonon calculations reveal the factors that determine which of the two scenarios dominates the transition. At the experimentally reported rhombohedral-cubic transition temperature, the calculated fluorine displacements are fast enough to overcome forward and backward a barrier of less than 30 kJ mol-1, leading to an average structure with cubic symmetry. In addition, lattice strain effects observed in epitaxial growth and nanocrystallite experiments involving BX3 compounds are successfully mimicked by computing the phase stability of FeF3 under negative pressures. We predict a transition pressure at -1.8 GPa with a relative volume change around 5%, consistent with a first-order transition from the rhombohedral to the cubic structure. Overall, our study illustrates how, by strain tuning, either a thermodynamic or a kinetic pathway can be selected for this transformation.

Anatomical changes in stem and root of soybean plants submitted to salt stress.

The soybean is a legume that is widely cultivated in many countries due to the high levels of protein and oil contained in its seed, and is used for human and animal nutrition. However, salinity affects more than 800 million hectares worldwide, limiting global agricultural production. The aim of this research was to evaluate the structural behaviour of the roots and stems under progressive salt stress, detailing the possible anatomical modifications to these organs in soybean plants during this stress. The plants were randomized into five treatments (0, 50, 100, 150 and 200 mm NaCl). All the root regions studied and exposed to 100 mm Na+ exhibited increases in the epidermis and endodermis and formation of lysogenic aerenchyma with increasing salinity, revealing the protective roles of these structures in reducing Na+ influx. In the stem, increases in the cortex and pith in the first internode subject to 100 mm Na+ suggest anatomical responses that aim to minimize oxidative stress. Soybean plants subjected to progressive salt stress (>50 mm Na+ ) avoided cavitation and loss of function linked to vessel elements, reducing the metaxylem in all the root and stem regions analysed. Finally, our results confirm anatomical changes to the roots and stems.

Chemical pressure-chemical knowledge: squeezing bonds and lone pairs within the valence shell electron pair repulsion model.

The valence shell electron pair repulsion (VSEPR) model is a demanding testbed for modern chemical bonding formalisms. The challenge consists in providing reliable quantum mechanical interpretations of how chemical concepts such as bonds, lone pairs, electronegativity, or hypervalence influence (or modulate) molecular geometries. Several schemes have been developed thus far to visualize and characterize these effects; however, to the best of our knowledge, no scheme has yet incorporated the analysis of the premises derived from the ligand close-packing (LCP) extension of the VSEPR model. Within the LCP framework, the activity of the lone pairs of the central atom and ligand-ligand repulsions constitute the two key features necessary to explain certain controversial molecular geometries that do not conform to the VSEPR rules. Considering the dynamical picture obtained when electron local forces at different nuclear configurations are evaluated from first-principles calculations, we investigate the chemical pressure distributions in a variety of molecular systems, namely, electron-deficient molecules (BeH2, BH3, BF3), several AX3 series (A: N, P, As; X: H, F, Cl), SO2, ethylene, SF4, ClF3, XeF2, and nonequilibrium configurations of water and ammonia. Our chemical pressure maps clearly reveal space regions that are totally consistent with the molecular and electronic geometries predicted by VSEPR and provide a quantitative correlation between the lone pair activity of the central atom and electronegativity of ligands, which are in agreement with the LCP model. Moreover, the analysis of the kinetic and potential energy contributions to the chemical pressure allows us to provide simple explanations on the connection between ligand electronegativity and electrophilic/nucleophilic character of the molecules, with interesting implications in their potential reactivity. NH3, NF3, SO2, BF3, and the inversion barrier of AX3 molecules are selected to illustrate our findings.

Urban weather data and building models for the inclusion of the urban heat island effect in building performance simulation.

This data article presents files supporting calculation for urban heat island (UHI) inclusion in building performance simulation (BPS). Methodology is used in the research article "From urban climate to energy consumption. Enhancing building performance simulation by including the urban heat island effect" (Palme et al., 2017) [1]. In this research, a Geographical Information System (GIS) study is done in order to statistically represent the most important urban scenarios of four South-American cities (Guayaquil, Lima, Antofagasta and Valparaíso). Then, a Principal Component Analysis (PCA) is done to obtain reference Urban Tissues Categories (UTC) to be used in urban weather simulation. The urban weather files are generated by using the Urban Weather Generator (UWG) software (version 4.1 beta). Finally, BPS is run out with the Transient System Simulation (TRNSYS) software (version 17). In this data paper, four sets of data are presented: 1) PCA data (excel) to explain how to group different urban samples in representative UTC; 2) UWG data (text) to reproduce the Urban Weather Generation for the UTC used in the four cities (4 UTC in Lima, Guayaquil, Antofagasta and 5 UTC in Valparaíso); 3) weather data (text) with the resulting rural and urban weather; 4) BPS models (text) data containing the TRNSYS models (four building models).

Brassinosteroids improve photosystem II efficiency, gas exchange, antioxidant enzymes and growth of cowpea plants exposed to water deficit.

Water deficit is considered the main abiotic stress that limits agricultural production worldwide. Brassinosteroids (BRs) are natural substances that play roles in plant tolerance against abiotic stresses, including water deficit. This research aims to determine whether BRs can mitigate the negative effects caused by water deficiency, revealing how BRs act and their possible contribution to increased tolerance of cowpea plants to water deficit. The experiment was a factorial design with the factors completely randomised, with two water conditions (control and water deficit) and three levels of brassinosteroids (0, 50 and 100 nM 24-epibrassinolide; EBR is an active BRs). Plants sprayed with 100 nM EBR under the water deficit presented significant increases in ΦPSII, qP and ETR compared with plants subjected to the water deficit without EBR. With respect to gas exchange, PN, E and gs exhibited significant reductions after water deficit, but application of 100 nM EBR caused increases in these variables of 96, 24 and 33%, respectively, compared to the water deficit + 0 nM EBR treatment. To antioxidant enzymes, EBR resulted in increases in SOD, CAT, APX and POX, indicating that EBR acts on the antioxidant system, reducing cell damage. The water deficit caused significant reductions in Chl a, Chl b and total Chl, while plants sprayed with 100 nM EBR showed significant increases of 26, 58 and 33% in Chl a, Chl b and total Chl, respectively. This study revealed that EBR improves photosystem II efficiency, inducing increases in ΦPSII, qP and ETR. This substance also mitigated the negative effects on gas exchange and growth induced by the water deficit. Increases in SOD, CAT, APX and POX of plants treated with EBR indicate that this steroid clearly increased the tolerance to the water deficit, reducing reactive oxygen species, cell damage, and maintaining the photosynthetic pigments. Additionally, 100 nM EBR resulted in a better dose-response of cowpea plants exposed to the water deficit.

[Intravenous regional anesthesia with long-acting local anesthetics. An update]. / Anestesia regional intravenosa con anestésicos locales de larga duración. Actualización.

Intravenous regional anesthesia is a widely used technique for brief surgical interventions, primarily on the upper limbs and less frequently, on the lower limbs. It began being used at the beginning of the 20th century, when Bier injected procaine as a local anesthetic. The technique to accomplish anesthesia has not changed much since then, although different drugs, particularly long-acting local anesthetics, such as ropivacaine and levobupivacaine in low concentrations, were introduced. Additionally, drugs like opioids, muscle relaxants, paracetamol, neostigmine, magnesium, ketamine, clonidine, and ketorolac, have all been investigated as adjuncts to intravenous regional anesthesia, and were found to be fairly useful in terms of an increased onset of operative anesthesia and longer lasting perioperative analgesia. The present article provides an overview of current knowledge with emphasis on long-acting local anesthetic drugs.

Genetic epidemiology of Charcot-Marie-Tooth in the general population.

BACKGROUND AND PURPOSE: the frequency of different Charcot-Marie-Tooth (CMT) genotypes has been estimated in clinic populations, but prevalence data from the general population are lacking. METHODS: our population-based genetic epidemiological survey included persons with CMT residing in eastern Akershus County, Norway. The participants were interviewed and examined by one geneticist/neurologist and classified clinically, neurophysiologically and genetically. RESULTS: two hundred and forty-five persons from 116 families had CMT. This corresponds to 1 per 1214 persons (95% CI 1062-1366) have CMT in the general population. CMT1 (motor conduction velocity (MCV) <38 m/s), CMT2 (MCV >38 m/s) and CMT intermediate (MCV 25-45 m/s) were found in 48.2%, 49.4% and 2.4% of the families. A total of 27.2% of the families and 28.6% of the affected had a mutation in the investigated CMT genes. The prevalence of the peripheral myelin protein 22 (PMP22) duplication and point mutation in the connexin32 (Cx32), myelin protein zero (MPZ) and mitofusin2 (MFN2) genes was found in 13.6%, 6.2%, 1.2%, 6.2% of the families, and in 19.6%, 4.8%, 1.1%, 3.2% of the affected, respectively. None of the families had point mutations in the early growth response 2 (EGR2), PMP22 or small integral membrane protein of lysosome/late endosome (SIMPLE) genes. CONCLUSIONS: CMT is the most common inherited neuropathy. At present, 43 CMT genes are known, and an examination of all known genes would probably only identify mutations in approximately 50% of those with CMT. Thus, it is probable that at least 30-50 CMT genes are yet to be identified.

Digestion of cattle manure: thermogravimetric kinetic analysis for the evaluation of organic matter conversion.

Anaerobic digestion of cattle manure was studied under thermophilic and mesophilic conditions with the purpose of evaluating the effect of temperature on the quality of the final digestate. Non-isothermal thermogravimetric kinetic analysis was applied for assessing organic matter conversion of biological stabilization. The mathematical approximation proves to be a useful tool for evaluating the differences attained during biological degradation. The anaerobic digestion of the organic substrate resulted in a reduction of the activation energy value obtained from the different applied kinetic models. Results obtained from thermal kinetic analysis were in accordance with those from the monitoring of the anaerobic digestion process. The higher values of methane yield reported for the mesophilic digestion in comparison to that of the thermophilic indicated a greater capability of the former process in the utilization of substrate and thus a higher conversion of organic matter which can be quantified by the activation energy value.

Digestion of cattle manure under mesophilic and thermophilic conditions: characterization of organic matter applying thermal analysis and 1H NMR.

Digestion of cattle manure collected from a livestock farm together with bedding material (straw) has been studied under mesophilic and thermophilic conditions in batch reactors. The digestion was carried out for a prolonged period with the aim of evaluating the changes undergone by the organic matter. The mesophilic digestion carried out revealed a greater capacity to produce gas and transform organic matter, while a higher conversion rate, but a lower gas yield, was obtained under thermophilic conditions. Degradation of the organic matter was evaluated by means of thermal analysis and (1)H NMR. Stabilisation through anaerobic digestion (either mesophilic or thermophilic) resulted in an increase in the quality of the organic matter, as characterised by an enrichment in thermostable compounds, and an accumulation of long chain aliphatic materials. The experiments performed demonstrated the transformation of organic matter into complex materials under anaerobic conditions with an accumulation of aliphatic components under both types of conditions tested. Degradation through mesophilic digestion, in comparison to the thermophilic process, resulted in a greater destruction of straw particles.

Epidemiology of chronic inflammatory bowel disease in the Northern area of Huelva.

OBJECTIVE: To know the different epidemiologic aspects of chronic inflammatory bowel disease (IBD) in the Northern area of the province of Huelva. MATERIAL AND METHODS: we carried out a retrospective (1980-1996) and prospective (1996-2003) study of all patients diagnosed with IBD in the Northern area of Huelva, with 77,856 inhabitants. The distribution of Crohn s disease (CD) and ulcerative colitis (UC) was analyzed, as well as sex, age and smoking habit at the time of diagnosis, familial aggregation, appendicectomy rate, phenotype (anatomical site and clinical types), extraintestinal manifestations, and immunosuppressive therapy or surgical requirements. RESULTS: 70 patients with IBD were studied, 40 with UC and 30 with CD. Sex distribution was 39 (55.7%) males (55% with CD vs 56.6% with UC; NS) and 31 (44.3%) females (45% with CD vs 43.3% with UC; NS). Mean age at presentation was 44.7 +/- 19.32 years in UC vs 32.3 +/- 16.43 in CD; p < 0.001. Familial association was 7.1%. Previous appendicectomy was referred in 2.5% of patients with UC vs 36.7% of those with CD (p < 0.001), and the percentage of smokers was also higher in CD 66.7% vs CU 12.5% (p < 0.001). Anatomical site in UC was: proctitis, 20%; proctosigmoiditis/left colon, 42.5%; extensive colitis, 25%; and pancolitis, 12.5%; in CD was: terminal ileum, 43.3%; colon, 20%; and ileo-colon, 36.7%. The disease patterns were: inflammatory 56.7%, obstruction 26.7%, and fistulization 16.7%. Extraintestinal manifestations were diagnosed in 7.5% of patients with UC vs 16.6% patients with CD; surgery was performed in one patient with UC vs 10 with CD, and one patient with UC required immunosuppressive treatment vs 12 with CD. A multivariant analysis showed that younger age and smoking habit were risk factors for CD vs advanced age in UC, in which case, the smoking habit was a protective factor. The mean incidence rate of IBD starting from 1996 and expressed in cases/100,000 inhabitants/year was 5.2 for UC and 6.6 for CD. CONCLUSIONS: The mean incidence of UC in our area was 5.2 cases/100,000/inhabitants/year, and 6.6 for CD. Patients presenting with CD are diagnosed at a significantly younger age that those with UC; the smoking habit is a risk factor for CD while it protects from UC. The characteristics of IBD in our geographical area do not differ substantially from those in other regions of Spain.

Predictors of mortality in patients undergoing surgery for ruptured aortic aneurysm.

BACKGROUND: A study was designed to determine significant variables that could be used to predict survival in patients with ruptured abdominal aortic aneurysm. PATIENTS AND METHODS: Data of 106 unselected consecutive patients with ruptured abdominal aortic aneurysm undergoing operation between 1989 and 1998 were identified from a prospective hospital-based registry. A total of 32 variables were analyzed including demographic characteristics, vascular risk factors, coexisting conditions, preoperative findings, intraoperative variables, and postoperative complications. Preoperative and intraoperative variables related to vital status (alive, death) in the univariate analysis were subjected to stepwise linear regression analysis to determine whether a combination of variables would predict death. Of 99 evaluable patients, 48 died (mortality rate 48.5%). RESULTS: At univariate analysis, age, serum creatinine, hemoglobin, electrocardiographic ischemia, loss of consciousness on admission, preoperative shock, supra-renal rupture, and transfusion requirements were significantly associated with 30-day operative mortality. Postoperative complications except sepsis, mesenteric ischemia, and neurologic events were significantly associated with mortality. Electrocardiographic ischemia, shock, and supra-renal rupture appeared to be independent predictors of mortality in the multivariate analysis. The cumulative effect of 0, 1, and > or = 2 risk factors on mortality was 29%, 39%, and 90%, respectively. CONCLUSIONS: Electrocardiographic ischemia, preoperative shock, and supra-renal rupture were predictors of death in patients with ruptured abdominal aortic aneurysm.

Impact of endovascular repair for abdominal aortic aneurysms in octogenarians.

A total of 50 consecutive patients (86% male; median age, 82 years) underwent endovascular repair of abdominal aortic aneurysms (AAAs) ranging from 4.0 to 9.0 cm (median, 5.2 cm). Efficacy of aneurysm exclusion was assessed by angiography, duplex scan, and/or contrast-enhanced computed tomography (CT). Acute technical success was 82%. Access failed in one patient, and immediate conversion to open operation was required in two patients. Improper deployment of the endoluminal graft (ELG) across the renal arteries occurred in one patient. The median operation time, estimated blood loss, packed red blood cells received, contrast volume, and length of intensive care and hospital stay were 128 min, 200 mL, 0.1 unit, 297 mL, 0.9 days, and 3 days, respectively. ELG limb thrombosis was seen in one patient. There were 4 (8%) early endoleaks, and 2 endoleaks were discovered in other patients at 3 and 6 months. Local/vascular and remote/systemic postoperative complications were seen in 13 (26%) and 9 (18%) patients, respectively. At a median follow-up of 11 months (range 2 to 36 months), clinical success was 78%. The aneurysm sac diameter (n = 49) decreased from a preoperative median of 5.2 to 4.7 cm (p = 0.0001). Technical success was high, and results at 11 months were satisfactory. Long-term outcomes require further study.

Transrenal fixation of aortic endografts: intermediate follow-up of a single-center experience.

PURPOSE: To examine the fate of the renal ostia following transrenal fixation of endovascular aortic stent-grafts. METHODS: Thirty-five patients (29 men; mean age 75 years) undergoing endovascular repair for abdominal aortic aneurysms (AAAs) had transrenal fixation of the uncovered proximal stent due to a short (< 1.5 cm long) or conical neck or a periprocedural endoleak. Eighteen (51%) patients were hypertensive; 7 (20%) had renal artery stenoses (RAS). Outcome measures included blood pressure, serum creatinine, computed tomography, and renal artery duplex scans. RESULTS: Two patients with > or = 60% RAS had renal stents placed during the endograft procedure; the other 5 RAS patients were normotensive and their renal lesions were not treated. Overall technical success was 82.9% (29/35). One (2.9%) case was converted due to graft twisting. There were 5 (14.2%) early endoleaks. Transient postoperative creatinine elevations were observed in 5 (14.2%) cases. Over a median 11-month period (range 2-24), no secondary endoleaks or silent renal artery occlusions were seen. One normotensive patient with an untreated > or = 60% renal lesion developed hypertension and severe stenosis (99%) at 4 months; stenting through the interstices of the transrenal stent was performed. No disease progression was seen in the other 6 RAS patients. CONCLUSIONS: In the intermediate period, transrenal fixation appears to have no adverse effects on renal blood flow. Moreover, in patients with no evidence of renal disease or preoperative RAS < 60%, it does not precipitate or cause progression of renal stenosis. However, patients with preoperatively documented RAS > or = 60% are a concern and mandate further study.