Reconstruction of congenital pseudarthrosis of the radius with a vascularized tibial periosteal transplant: A case report.

Congenital pseudarthrosis of the forearm poses a considerable challenge because of its rarity. The objective of this report is to introduce a novel surgical technique for its treatment. Here, we document a case of congenital pseudarthrosis of the radius in a 3-year-old boy diagnosed with type-1 neurofibromatosis. The surgical treatment involved the excision of approximately 9 cm of native radial periosteum and a bifocal radius osteotomy, which was supplemented with a vascularized tibial periosteal transplant to facilitate bone healing. Anastomosis between the anterior tibial vessels and radial vessels was performed. No immediate or late postoperative complications were observed. After 3 weeks, a robust callus formation was observed, and during a follow-up examination 3 years and 4 months later, a wide range of active forearm rotation was noted. This report suggests that vascularized periosteal flaps show promise as a viable treatment option for congenital pseudarthrosis of the forearm. They offer an alternative to vascularized fibular grafts or single-bone forearm constructs.

WHAT IS THE EPIDEMIOLOGICAL PROFILE OF ACUTE HAND INFECTIONS AT A HOSPITAL IN SAO PAULO?

Objective: To determine the epidemiological profile of patients treated at a philanthropic hospital specialized in Orthopedics and Traumatology, located in a significant urban center, and evaluate the efficacy of initial empirical antibiotic treatment. Methods: Patients diagnosed with hand infections from September 2020 to September 2022 were included, excluding cases related to open fractures or post-surgical infections and those with incomplete medical records. The chi-square test was performed using STATISTICA ® software to correlate various variables. Results: A total of 34 patients participated, including 24 men and 10 women, with an average age of 41.9 years. Most male patients had Diabetes Mellitus, HIV, and drug addiction, and they resided in urban areas. Half of the patients did not report any apparent trauma. The most common infectious agent was Staphylococcus aureus*. Nearly 62% of patients required a change in the initial antibiotic regimen, with Penicillin being the most frequently substituted medication. Beta-lactam antibiotics and Quinolones were the most effective. Conclusion: These results suggest the importance of carefully evaluating the epidemiological profile of patients with acute hand infections and improving initial empirical treatment to ensure appropriate and effective therapy. Level of Evidence IV, Cross-Sectional Observational Study.

Objetivo: Determinar o perfil epidemiológico de pacientes atendidos em um hospital filantrópico referência em Ortopedia e Traumatologia localizado em um centro urbano importante, e avaliar a eficácia do tratamento antibiótico empírico inicial. Métodos: Foram incluídos pacientes com diagnóstico de infecção na mão, atendidos no período de setembro de 2020 a setembro de 2022, excluindo-se casos relacionados a fraturas expostas ou pós-cirúrgicas e aqueles com prontuários incompletos. Realizou-se o teste do qui-quadrado, utilizando o software STATISTICA ® para correlacionar diversas variáveis. Resultados: Participaram do estudo 34 pacientes, sendo 24 homens e 10 mulheres, com média de idade de 41,9 anos. A maioria era de homens, com alta incidência de diabetes mellitus, HIV e drogadição, que residiam em áreas livres. Metade não relatou trauma evidente. O agente infeccioso mais comum foi o Staphylococcus aureus. Aproximadamente 62% dos pacientes precisaram de troca do esquema inicial de antibióticos, sendo a penicilina o medicamento mais frequentemente substituído. Os antibióticos beta-lactâmicos e quinolonas foram os mais eficientes. Conclusão: Esses resultados sugerem a importância de avaliar cuidadosamente o perfil epidemiológico dos pacientes com infecções agudas na mão e aprimorar o tratamento empírico inicial para garantir uma terapia adequada e eficaz. Nível de Evidência IV, Estudo Observacional Transversal.

Study of the degradation in an ultisol of alginate-chitosan complex and its stability and applicability as a soil conditioner.

The present work describes the process of degradation of a polyelectrolytic complex (PEC) based on sodium alginate (ALG) and chitosan (CHI), buried for different time intervals, in a clayey soil (ultisol) collected from the municipality of Campos dos Goytacazes, in the northern region of the state of Rio de Janeiro, Brazil. The influence of PEC on soil moisture was also investigated. The results showed that soil moisture increased with the presence of PEC after 7 days of testing, and remained high until the end of the study. FTIR and Raman spectra showed that the breaking of the glycosidic bond (C-O-C) was responsible for the PEC degradation. Thermogravimetry results revealed that alginate was possibly degraded faster than chitosan. Microscopic analysis of the PEC revealed a fragile and fragmented surface of the samples that were buried, in comparison with those not buried. The microbiological assays of the soil confirmed the biodegradation of the polysaccharides. Chemical analysis of soil indicated that PEC did not significantly influence soil fertility. Therefore, we conclude that the PEC (ALG: CHI), formed only by electrostatic interaction, buried in clayey soil, even being biodegraded, can be a promising soil conditioner for agricultural applications.

Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests.

Tropical forests face increasing climate risk1,2, yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for example, [Formula: see text]50) and hydraulic safety margins (for example, HSM50) are important predictors of drought-induced mortality risk3-5, little is known about how these vary across Earth's largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters [Formula: see text]50 and HSM50 vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both [Formula: see text]50 and HSM50 influence the biogeographical distribution of Amazon tree species. However, HSM50 was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM50 are gaining more biomass than are low HSM50 forests. We propose that this may be associated with a growth-mortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM50 in the Amazon6,7, with strong implications for the Amazon carbon sink.

Ferrihydrite synthesis in the presence of amino acids and artificial seawater.

Ferrihydrite is widespread in clays, soils, and living organisms and was found on Mars. This iron-mineral could be found on the prebiotic Earth, which also contained simple monomeric amino acids. For prebiotic chemistry, it is important to understand how amino acids have an effect on the process of iron oxide formations. There are three important results in this work: (a) preconcentration of cysteine and aspartic acid, (b) formation of cystine and probably the cysteine peptide occurred during ferrihydrite syntheses, and (c) amino acids have an effect on iron oxide synthesis. For samples containing aspartic acid and cysteine, their presence on the surface or mineral structure can be confirmed by FT-IR spectra. Surface charge analysis showed a relatively high decrease for samples synthesized with cysteine. Scanning electron microscopy did not show marked morphological differences among the samples, except for the seawater sample containing cysteine, which had a lamina-shaped morphology surrounded by circular iron particles, indicating the possible formation of a cysteine structure involving iron oxide particles. The thermogravimetric analysis of the samples indicates that the presence of salts and amino acids in the synthesis of ferrihydrite has an effect on the thermal behavior of the iron oxide/amino acids and modifying the water-loss temperature. The heating of the cysteine samples, synthesized in distilled water and artificial seawater, showed several peaks of degradation of cysteine. In addition, heating of the aspartic acid samples produced the polymerization of this amino acid and peaks of degradation of it. FTIR spectra and XRD patterns did not indicate the precipitation of methionine, 2-aminoisobutyric acid, lysine, or glycine with the iron oxide formations. However, the heating of the glycine, methionine and lysine samples, synthesized in artificial seawater, showed peaks that could be attributed to the degradation of them. Then this could be an indication that these amino acids precipitate with the minerals during the syntheses. Also, the dissolution of these amino acids in artificial seawater prevents the formation of ferrihydrite.

Neuroma-in-continuity: a review of pathophysiology and approach to the affected patient.

A neuroma-in-continuity is a neuroma resulting from a nerve injury in which internal neuronal elements are partially disrupted (with a variable degree of disruption to the endoneurium and perineurium) while the epineurium typically remains intact. The portion of injured axons are misdirected and embedded in connective tissue, which may give rise to local neuroma pain and a distal nerve deficit. The lesion may result from a multitude of injury mechanisms, and clinical presentation is often variable depending on the nerve affected. Clinical, electrodiagnostic, and imaging examinations are helpful in assessing the extent and degree of the lesion. If no clear evidence of recovery is identified within 3-4 months post-injury, the patient may benefit from operative exploration. Surgical management options include neurolysis, neuroma resection, nerve grafting, and nerve transfer, or a combination of modalities. A primary consideration of surgery is the possibility of further downgrading nerve function in the pursuit of more, thereby highlighting the need to carefully weigh the advantages and disadvantages prior to surgical intervention. The objective of this review article is to describe the current understanding of the pathophysiology of neuroma-in-continuity lesions, and to review the approach to the affected patient including clinical evaluation, ancillary testing, and intraoperative assessment and treatment options.

Nerve root transfer from C4 to C5 in brachial plexus injuries. Anatomical study and description of the surgical technique.

Objective This is an anatomical study of C4 and C5 roots for nerve transfers in upper brachial plexus injuries, with surgical technique demonstration. Methods Fifteen brachial plexuses from both male and female cadavers were dissected. Morphological features of C4 and C5 roots were recorded and analyzed, followed by a neurotization simulation. Results In all dissections, C4 and C5 roots morphological features allowed their mobilization and neurotization with no need for a nerve graft. The surgical technique spared important regional nerve branches. Conclusion Based on these data, we conclude that C4-C5 nerve transfers are feasible and result in no additional neurological deficit in upper brachial plexus injuries.

The Effect of Goethites on the Polymerization of Glycine and Alanine Under Prebiotic Chemistry Conditions.

After pre concentration of monomers, polymerization is the second most important step for molecular evolution. The formation of peptides is an important issue for prebiotic chemistry and consequently for the origin of life. In this work, goethite was synthesized by two different routes, named goethite-I and goethite-II. Although both samples are goethite, Far-FT-IR spectroscopy and EPR spectroscopy showed differences between them, and these differences had an effect on the polymerization of glycine and alanine. For the amino acid polymerization, three protocols were used, that resembled prebiotic Earth conditions: a) amino acid plus goethite were mixed and heated at 90 °C for 10 days in solid state, b) a wet impregnation of the amino acid in the goethite, with subsequent heating at 90 °C for 10 days in solid state, and c) 10 wet/dry cycles each one for 24 h at 90 °C. Experiments with glycine plus goethite-II, using protocols B and C, produced only Gly-Gly. In addition, for the C protocol the amount of Gly-Gly synthesized was 3 times higher than the amount of Ala-Ala. Goethite-I presented a decrease in the EPR signal, when it was submitted to the protocols with and without amino acids. It is probable the decrease in the intensity of the EPR signal was due to a decrease in the imperfections of the mineral. For all protocols the mixture of alanine plus goethite-I or goethite-II produced c(Ala-Ala). However, for wet/dry cycles, protocol C presented higher yields (p < 0.05). In addition, Ala-Ala was produced using protocols A and C. The c(Ala-Ala) formation fitted a zero-order kinetic equation model. The surface areas of goethite-I and goethite-II were 35 m2 g-1 and 37 m2 g-1, respectively. Thermal analysis indicated that the mineral changes the thermal behavior of the amino acids. The main reactions for the thermal decomposition of glycine were deamination and dehydration and for alanine was deamination.

Magnetite Synthesis in the Presence of Cyanide or Thiocyanate under Prebiotic Chemistry Conditions.

Magnetite is an iron oxide mineral component of primitive Earth. It is naturally synthesized in different ways, such as magma cooling as well as olivine decomposition under hydrothermal conditions. It is probable magnetite played a significant role in biogenesis. The seawater used in the current work contained high Mg2+, Ca2+ and SO42- concentrations, unlike the seawater of today that has high Na+ and Cl- concentrations. It is likely that this seawater better resembled the ion composition of the seas of the Earth from 4 billion years ago. Cyanide and thiocyanate were common molecules in prebiotic Earth, and especially in primitive oceans, where they could act on the magnetite mechanism synthesis via Fe2+ interaction. In this research, magnetite samples that were synthesized under prebiotic conditions in the presence of cyanide or thiocyanate, (both with and without artificial seawater), showed that, besides magnetite, goethite and ferrihydrite can be produced through different Fe2+-ion interactions. Cyanide apparently acts as a protective agent for magnetite production; however, thiocyanate and seawater 4.0 Gy ions produced goethite and ferrihydrite at different ratios. These results validate that Fe3+ oxides/hydroxides were possibly present in primitive Earth, even under anoxic conditions or in the absence of UV radiation. In addition, the results show that the composition of water in early oceans should not be neglected in prebiotic chemistry experiments, since this composition directly influences mineral formation.

Adenine Adsorbed onto Montmorillonite Exposed to Ionizing Radiation: Essays on Prebiotic Chemistry.

Most adsorption and radiolysis experiments related to prebiotic chemistry studies are performed in distilled water or sodium chloride solutions. However, distilled water and sodium chloride solutions do not represent the composition of the primitive seas of Earth. In this work, an artificial seawater with ion abundances Mg2+ > Ca2+ >> Na+ ≈ K+ and SO42- >> Cl- was used, one that is different from the average composition of seawater today. This artificial seawater is named seawater 4.0 Ga, since it better represents the composition of the major constituents of seawater of primitive Earth. The radiolysis of adenine adsorbed onto montmorillonite was studied. The most important result is that adenine is adsorbed onto montmorillonite, when it is dissolved in artificial seawater 4.0 Ga, and the clay protects adenine against gamma radiation decomposition. However, desorption of adenine from montmorillonite was possible only with 0.10 mol L-1 of KOH. This result indicates that adenine was strongly bonded to montmorillonite. Fourier transform infrared spectroscopy showed that NH2 group and electrostatic interactions, between negatively charged montmorillonite and positively charged adenine, are responsible for adsorption of adenine onto montmorillonite. In addition, X-ray diffractograms showed that adenine enters in the interlayer space of montmorillonite.

FUNCTIONAL OUTCOME OF OBERLIN PROCEDURE.

OBJECTIVE: To evaluate the functional outcome of patients with traumatic brachial plexus injury undergoing the Oberlin procedure. METHODS: Eighteen patients were assessed, comprising 17 men (94.4%) and 1 woman (5.6%), mean age 29.5 years (range 17-46 years), with upper traumatic brachial plexus injury (C5-C6 and C5-C7). We assessed active range of motion of the elbow, elbow flexion muscle strength and hand-grip strength, and applied the DASH (Disabilities of the Arm, Shoulder and Hand) questionnaire. RESULTS: Four patients (22.2%) did not achieve effective elbow flexion strength (BMRC Grade 3). Mean active range of motion was 100.2° (±45.6°), and we observed a mean percentage of strength recovery relative to the contralateral limb of 35.5% (0-66.3%). Elbow flexion (p = 0.0001) and hand-grip (p = 0.0001) strength levels were lower on the affected side. CONCLUSION: The surgical technique described by Oberlin for brachial plexus injuries proved effective for restoring elbow flexion and produced no functional sequelae in the hand. Bicep strength outcomes were better when surgery was performed within 12 months of injury. Level of evidence II, retrospective study.

OBJETIVO: Avaliar o resultado funcional dos pacientes com lesão traumática do plexo braquial submetidos à cirurgia de Oberlin. MÉTODOS: Foram analisados 18 pacientes, sendo 17 homens (94,4%), com idade média de 29,5 anos (17 a 46 anos), com lesão traumática alta do plexo braquial (C5-C6 e C5-C7). Avaliamos a amplitude de movimento ativa do cotovelo, a força muscular de flexão do cotovelo e a força de preensão palmar, e aplicamos o questionário Disabilities of the Arm, Shoulder and Hand (DASH). RESULTADOS: Quatro pacientes (22,2%) não obtiveram força eficaz de flexão do cotovelo BRMC (Grau 3). A amplitude de movimentação ativa apresentou média de 100,2° (± 45,6°) e observamos média de 35,5% (0 a 66,3%) de percentual de recuperação da força em relação ao membro contralateral. Foi observada menor força de flexão de cotovelo (p = 0,0001) e de preensão manual (p = 0,0001) no lado acometido. CONCLUSÃO: A cirurgia descrita por Oberlin para lesões do plexo braquial mostrou-se eficiente para a restauração da flexão do cotovelo e não deixou sequelas funcionais para a mão. Os resultados para a força do bíceps são melhores nas cirurgias realizadas com menos de 12 meses de lesão. Nível de evidência II, estudo retrospectivo.

The effect of pH and ionic strength on the adsorption of glyphosate onto ferrihydrite.

Although, glyphosate (N-(phosphonomethyl) glycine) is one of the most widely used herbicides in the world, its interaction with poorly crystalline iron oxides, such as ferrihydrite, is not well studied. In this research, we examined the adsorption of glyphosate onto ferrihydrite using infrared spectroscopy (FT-IR), electron paramagnetic resonance spectroscopy (EPR), adsorption kinetic models and adsorption isotherm models. The effect of pH and sodium chloride concentration on the adsorption of glyphosate onto ferrihydrite as well as the effect of extractors (CaCl2 0.010 mol L-1 and Mehlich) on the desorption of glyphosate were also evaluated. There are two important findings described in this work. First, 84% of adsorbed glyphosate strongly interacted to ferrihydrite as an inner-sphere complex and phosphate and amine groups are involved in this interaction. Second, an increase of sodium chloride salt concentration increased the adsorption of glyphosate onto ferrihydrite. The non-linear Langmuir model and pseudo second order model showed a good agreement of theoretical limit of glyphosate adsorbed onto ferrihydrite, 54.88 µg mg-1 and 48.8 µg mg-1, respectively. The adsorption of glyphosate onto ferrihydrite decreased when the pH increased. Under the conditions used in this work, EPR spectra did not show dissolution of ferrihydrite. Surface area, pore volume and pHpzc of ferrihydrite decreased after adsorption of glyphosate.

ASSESSMENT OF THE RESULTS OF ACCESSORY TO SUPRASCAPULAR NERVE TRANSFER.

OBJECTIVE: Nerve transfers are an alternative in the reconstruction of traumatic brachial plexus injuries. In this study, we report the results of branchial plexus reconstruction using accessory to suprascapular nerve transfer. METHODS: Thirty-three patients with traumatic brachial plexus injuries underwent surgical reconstruction with accessory to suprascapular nerve transfers. The patients were divided into groups in which surgery was performed either within 6 months after the injury or more than 6 months after the injury. Results were assessed using the Constant score. RESULTS: There was no significant difference between the groups with respect to the Constant score. CONCLUSION: Accessory to suprascapular nerve transfer was not an efficient method for recovering active ROM or strength in the shoulder. However, it effectively improved pain control and shoulder stability. Level of evidence II, Retrospective Study.

OBJETIVO: A transferência de nervos é uma alternativa na reconstrução das lesões traumáticas do plexo braquial. Neste estudo, relatamos os resultados da reconstrução do plexo braquial com a transferência do nervo acessório para o nervo supraescapular. MÉTODOS: Trinta e três pacientes com lesões traumáticas do plexo braquial foram submetidos à reconstrução cirúrgica com transferência do nervo acessório para o nervo supraescapular. Os pacientes foram divididos em grupos em que a cirurgia foi realizada dentro de 6 meses a partir da lesão ou mais de 6 meses depois da lesão. Os resultados foram avaliados com o escore Constant. RESULTADOS: Não houve diferença significante entre os grupos com relação ao escore Constant. CONCLUSÃO: A transferência do nervo acessório para o nervo supraescapular não foi um método eficiente para recuperar a ADM ativa ou a força no ombro. No entanto, foi eficiente para melhorar o controle da dor e a estabilização do ombro. Nível de evidência II, Estudo Retrospectivo.

DOES COGNITIVE CAPACITY INTERFERE WITH THE OUTCOME OF OBERLIN TRANSFER?

OBJECTIVE: To determine the relationship between the functional outcome achieved following Oberlin transfer, the cognitive level of the patient, and the time elapsed between the trauma event and surgery. METHODS: Eighteen patients with a traumatic injury to the brachial plexus (C5-C6 and C5-C7) were evaluated. Seventeen (94.4%) patients were males and one (5.6%) was female, with a mean age of 29.5 years (range 17-46 years). We evaluated the active range of motion, elbow flexion strength, and Disabilities of the Arm, Shoulder and Hand (DASH) and determined the correlation between the procedural outcome and the patient's cognitive level, as assessed by the Mini-Mental State Exam (MMSE). RESULTS: We found statistically significant correlations between the MMSE scale and strength recovery (84.4%, p<0.001), which was classified as excellent, and between the MMSE and British Medical Research Council (BMRC) scales (78.4%, p>0.001), which classified cognitive level as good. CONCLUSIONS: We found a positive correlation between cognitive capacity and functional outcome of patients submitted to Oberlin surgery. The time elapsed between trauma and the surgical procedure showed an inversely proportional correlation with the strength of recovery. Level of Evidence II, Retrospective Study.

OBJETIVO: Determinar a relação entre o resultado funcional obtido com a cirurgia de Oberlin, o nível cognitivo do paciente e com o tempo decorrido entre o trauma e a cirurgia. MÉTODOS: Foram analisados dezoito pacientes, sendo 17 homens (94,4%) e uma mulher (5,6%), com idade média de 29,5 anos (17 a 46 anos), com lesão traumática alta do plexo braquial (C5-C6 e C5-C7). Avaliamos a amplitude de movimento ativa, a força muscular de flexão do cotovelo e o questionário DASH (Disabilities of the Arm, Shoulder and Hand) e determinamos a correlação entre o resultado obtido e o nível cognitivo do paciente, avaliado pelo Mini Exame do Estado Mental (MEEM). RESULTADOS: Observamos correlações de significância estatística entre MEEM e recuperação de força (84,4%, p<0,001), classificada como ótima; MEEM e BMRC - British Medical Research Council (78,4%, p> 0,001), classificada como boa. CONCLUSÕES: Verificamos correlação positiva entre a capacidade cognitiva e os resultados funcionais dos pacientes submetidos à cirurgia de Oberlin. O tempo decorrido entre o trauma e o procedimento cirúrgico apresenta uma relação inversamente proporcional com a recuperação da força. Nível de Evidencia II, Estudo retrospectivo.

Differences in xylem and leaf hydraulic traits explain differences in drought tolerance among mature Amazon rainforest trees.

Considerable uncertainty surrounds the impacts of anthropogenic climate change on the composition and structure of Amazon forests. Building upon results from two large-scale ecosystem drought experiments in the eastern Brazilian Amazon that observed increases in mortality rates among some tree species but not others, in this study we investigate the physiological traits underpinning these differential demographic responses. Xylem pressure at 50% conductivity (xylem-P50 ), leaf turgor loss point (TLP), cellular osmotic potential (πo ), and cellular bulk modulus of elasticity (ε), all traits mechanistically linked to drought tolerance, were measured on upper canopy branches and leaves of mature trees from selected species growing at the two drought experiment sites. Each species was placed a priori into one of four plant functional type (PFT) categories: drought-tolerant versus drought-intolerant based on observed mortality rates, and subdivided into early- versus late-successional based on wood density. We tested the hypotheses that the measured traits would be significantly different between the four PFTs and that they would be spatially conserved across the two experimental sites. Xylem-P50 , TLP, and πo , but not ε, occurred at significantly higher water potentials for the drought-intolerant PFT compared to the drought-tolerant PFT; however, there were no significant differences between the early- and late-successional PFTs. These results suggest that these three traits are important for determining drought tolerance, and are largely independent of wood density-a trait commonly associated with successional status. Differences in these physiological traits that occurred between the drought-tolerant and drought-intolerant PFTs were conserved between the two research sites, even though they had different soil types and dry-season lengths. This more detailed understanding of how xylem and leaf hydraulic traits vary between co-occuring drought-tolerant and drought-intolerant tropical tree species promises to facilitate a much-needed improvement in the representation of plant hydraulics within terrestrial ecosystem and biosphere models, which will enhance our ability to make robust predictions of how future changes in climate will affect tropical forests.

Limited acclimation in leaf anatomy to experimental drought in tropical rainforest trees.

Dry periods are predicted to become more frequent and severe in the future in some parts of the tropics, including Amazonia, potentially causing reduced productivity, higher tree mortality and increased emissions of stored carbon. Using a long-term (12 year) through-fall exclusion (TFE) experiment in the tropics, we test the hypothesis that trees produce leaves adapted to cope with higher levels of water stress, by examining the following leaf characteristics: area, thickness, leaf mass per area, vein density, stomatal density, the thickness of palisade mesophyll, spongy mesophyll and both of the epidermal layers, internal cavity volume and the average cell sizes of the palisade and spongy mesophyll. We also test whether differences in leaf anatomy are consistent with observed differential drought-induced mortality responses among taxa, and look for relationships between leaf anatomy, and leaf water relations and gas exchange parameters. Our data show that trees do not produce leaves that are more xeromorphic in response to 12 years of soil moisture deficit. However, the drought treatment did result in increases in the thickness of the adaxial epidermis (TFE: 20.5 ± 1.5 µm, control: 16.7 ± 1.0 µm) and the internal cavity volume (TFE: 2.43 ± 0.50 mm3 cm-2, control: 1.77 ± 0.30 mm3 cm-2). No consistent differences were detected between drought-resistant and drought-sensitive taxa, although interactions occurred between drought-sensitivity status and drought treatment for the palisade mesophyll thickness (P = 0.034) and the cavity volume of the leaves (P = 0.025). The limited response to water deficit probably reflects a tight co-ordination between leaf morphology, water relations and photosynthetic properties. This suggests that there is little plasticity in these aspects of plant anatomy in these taxa, and that phenotypic plasticity in leaf traits may not facilitate the acclimation of Amazonian trees to the predicted future reductions in dry season water availability.

Plasticity in leaf-level water relations of tropical rainforest trees in response to experimental drought.

The tropics are predicted to become warmer and drier, and understanding the sensitivity of tree species to drought is important for characterizing the risk to forests of climate change. This study makes use of a long-term drought experiment in the Amazon rainforest to evaluate the role of leaf-level water relations, leaf anatomy and their plasticity in response to drought in six tree genera. The variables (osmotic potential at full turgor, turgor loss point, capacitance, elastic modulus, relative water content and saturated water content) were compared between seasons and between plots (control and through-fall exclusion) enabling a comparison between short- and long-term plasticity in traits. Leaf anatomical traits were correlated with water relation parameters to determine whether water relations differed among tissues. The key findings were: osmotic adjustment occurred in response to the long-term drought treatment; species resistant to drought stress showed less osmotic adjustment than drought-sensitive species; and water relation traits were correlated with tissue properties, especially the thickness of the abaxial epidermis and the spongy mesophyll. These findings demonstrate that cell-level water relation traits can acclimate to long-term water stress, and highlight the limitations of extrapolating the results of short-term studies to temporal scales associated with climate change.

Computed tomography's influence on the classifications and treatment of the distal radius fractures.

INTRODUCTION: Distal radius fractures are common in emergency centers. The radiographic routine includes at least two radiographic projections used for diagnosing most of these fractures. Computed tomography (CT) is indicated for evaluating complex fractures that affect the articular surface, as well as the fragments' size and position. There are not enough comparative studies on choosing classification and treatment by means of the four radiographic projections and computed tomography (CT) and the association of these with the levels of expertise. METHODS: We conducted a randomized cross-sectional study by observing images from 61 patients with distal radius fractures organized in two phases: the first phase comprising radiographic images alone and the second one with those same images associated with tomograms. Seventeen evaluators with different levels of training and expertise classified the fractures according to the AO and Universal classification systems and proposed treatment guidelines. RESULTS: The agreement between the AO and Universal classification ratings was poor (worse for the former), with smaller Fleiss' kappa resulting from data obtained by orthopedics residents and non-specialist orthopedists. CT influenced the classification choice, with a higher change frequency for more complex patterns in the AO classification system and intra-articular and irreducible fractures in the Universal classification system, especially in the group comprised of orthopedic residents and orthopedic physicians. CT did not influence the treatment choice made by the group comprised of hand surgery residents and hand surgeons. CONCLUSION: The less experienced in hand surgery the observer was, the more important computed tomography was for determining the fracture pattern.

A Prebiotic Chemistry Experiment on the Adsorption of Nucleic Acids Bases onto a Natural Zeolite.

There are currently few mechanisms that can explain how nucleic acid bases were synthesized, concentrated from dilute solutions, and/or protected against degradation by UV radiation or hydrolysis on the prebiotic Earth. A natural zeolite exhibited the potential to adsorb adenine, cytosine, thymine, and uracil over a range of pH, with greater adsorption of adenine and cytosine at acidic pH. Adsorption of all nucleic acid bases was decreased in artificial seawater compared to water, likely due to cation complexation. Furthermore, adsorption of adenine appeared to protect natural zeolite from thermal degradation. The C=O groups from thymine, cytosine and uracil appeared to assist the dissolution of the mineral while the NH2 group from adenine had no effect. As shown by FT-IR spectroscopy, adenine interacted with a natural zeolite through the NH2 group, and cytosine through the C=O group. A pseudo-second-order model best described the kinetics of adenine adsorption, which occurred faster in artificial seawaters.

Anatomical study of sensory anastomoses in the hand.

OBJECTIVE: The aim of this study is to evaluate the prevalence, topography and morphometry of sensitive nervous anastomoses in the hand. METHODS: Thirty anatomic parts irrespective of race, gender and age have been dissected. Measurements of anastomoses' length, origin and terminus regarding the transverse carpal ligament were noted. The anastomoses were classified according to the scheme proposed by Meals & Shaner and modified by Bas & Kleinert. RESULTS: Type 1 anastomosis was the most prevalent. The distance between the origin of the anastomosis to the distal limit of the transverse carpal ligament was 0.7 cm in average. CONCLUSION: This study showed that Berretini anastomosis is high prevalent, usually beginning in the ulnar and distal nerve until the transverse carpal ligament. Level of Evidence IV, Case Series.