Small Morphological Changes Research Articles

Orientation and Grain Size in MAPbI3 Thin Films: Influence on Phase Transition, Disorder, and Defects

In recent years, record efficiencies of halide perovskite-based devices have been achieved by processing high-quality thin films, where small morphology differences seem to be relevant for optimized optoelectronic functionality. However, a detailed understanding on how small morphological changes in perovskite films affect their structural and optoelectronic properties is still missing. Here, we investigate the influence of small morphology differences (i.e., increased grain size and crystallographic orientation), which are induced by hot-pressing methylammonium lead iodide (MAPbI3) thin films, on the structural properties, phase transition behavior, energetic disorder, and defects. To this end, detailed temperature-dependent photoluminescence (PL) and absorption analyses from 300 K down to 5 K are performed. The morphology differences, confirmed by scanning electron microscopy and X-ray diffractometry analyses, result in an increased phase transition temperature for hot-pressed (HP) films, which we attribute to less strain. Moreover, fluence-dependent and transient PL measurements reveal a lower defect density in HP films. Here, besides grain size, also the degree of orientation appears to enhance the charge carrier lifetimes. The identified interdependence of strain and defect properties with film morphology suggests small differences in the perovskite’s energetic disorder. Our work thus emphasizes the importance that even small structural differences in halide perovskites have on their optoelectronic functionality, spurring their further optimization.

Flight performance and wing morphology in the bat Carollia perspicillata: biophysical models and energetics.

Studies on functional performance are important to understand the processes responsible for the evolution of diversity. Morphological trait variation within species influences the energetic cost of locomotion and impacts life history traits, with ecological and evolutionary consequences. This study examined wing morphology correlates of flight performance measured by energetic expenditure in the Seba's short-tailed bat, Carollia perspicillata. In the flight experiments, nature caught bats (59 females, 57 males) were allowed to fly for 3 min in a room. After each flight, thermographic images were taken to measure body temperature, and biophysical models were used to calculate sensible heat loss as a measure of energetic expenditure. Wing morphological traits were measured for each individual and associated with heat loss and power required to fly on performance surfaces. Wing morphological traits explained 7-10% of flight energetic cost, and morphologies with the best performance would save the energy equivalent to 9-30% of total daily requirements. The optimal performance areas within the C. perspicillata morphospace were consistent with predicted selection trends from the literature. A trade-off between demands for flight speed and maneuverability was observed. Wing loading and camber presented sexual dimorphism. These morphological differences are likely associated with more economical but less maneuverable flight in females, leading them to fly more often in open areas along the forest edge. Our findings demonstrate how small scale changes in wing morphology can affect life history strategies and fitness.

Non‐thermal plasma as an efficient pretreatment to lignocellulosic raw materials

AbstractNon‐thermal plasma is an ecologically correct technique that is increasingly being explored. In this work, plasma was applied as a delignification technique for different lignocellulosic residues (brewery, banana peel, and mango seed peel). The influence of non‐thermal plasma on the physical and chemical characteristics of the residues was also explored by the techniques scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), x‐ray diffraction (XRD), and RAMAN spectroscopy. Delignification of approximately 48% was observed in 5 min of the process for the brewery by‐product, 35% the mango seed shell, and 24% the banana peel. Small changes in morphology (SEM), degradation temperature (DSC), compositional analysis (FTIR, XRD, and RAMAN) after pretreatment with non‐thermal plasma were observed. Thus, we bring unprecedented results using non‐thermal plasma as an alternative pretreatment for different lignocellulosic residues, indicating an attractive technique for subsequent enzymatic hydrolysis and thus obtaining added‐value products, such as bioethanol and xylooligosaccharides.

Numerical study of sediment scour at meander flume outlet of boxed culvert diversion work.

BackgroundSediment scour at downstream of hydraulic structures is one of the main reasons threatening its stability. Several soil properties and initial input data have been studied to investigate its influence on scour hole geometry by both physical and numerical models. However, parameters of resistance affecting sedimentation and erosion phenomena have not been carried out in the literature. Besides, the auxiliary-like wing walls prevalently used in many real applications have been rarely addressed for their effect on morphological change.ResultsIn this study, a 3D Computational Fluid Dynamics model is utilized to calibrate the hydraulic characteristics of steady flow going through the culvert by comparison with experimental data, showing good agreement between water depth, velocity, and pressure profiles at the bottom of the boxed culvert. The results show that a grid cell of 0.015 m gave minimum NRMSE and MAE values in test cases. Another approach is numerical testing sediment scour at a meander flume outlet with a variety of roughness/d50 ratio (cs) and diversion wall types. The findings include the following: cs = 2.5 indicates the close agreement between the numerical and analytical results of maximum scour depth after the culvert; the influence of four types of wing wall on the geometrical deformation including erosion at the concave bank and deposition at the convex bank of the meander flume outlet; and two short headwalls represent the best solution that accounts for small morphological changes.ConclusionsThe influence of the roughness parameter of soil material and headwall types on sediment scour at the meander exit channel of hydraulic structure can be estimated by the numerical model.

Effective thermal conductivity in BCC and FCC lattices for all volume fractions and conductivity ratios: Analyses by microstructural efficiency and morphology factor and analytic models

The effective thermal conductivity of composite materials is of great interest for thermal storage applications demanding rapid charge and discharge behaviour. Open cell porous metal foams filled with phase change material are one class of composite in which small changes in morphology lead to large changes in effective conductivity. Regular lattices can be easily built by additive manufacturing techniques, but are often used as simple analogues of composites materials with randomly distributed particles or irregular foams, that can thus be studied using computational techniques. Through procedural steady state simulation of heat transfer through unit cells, the impact of morphology on the thermal response of spheres upon BCC and FCC lattices is quantified. The indices of normalised effective thermal conductivity, microstructural efficiency and morphology factor are given for all volume fractions and conductivity ratio 10−4 to 104. Simple empirical models are developed and are compared to experimental data. Recommendations are made on the most optimal morphology for combinations of volume fraction and conductivity ratio.

Influence of CNT Length on Dispersion, Localization, and Electrical Percolation in a Styrene-Butadiene-Based Star Block Copolymer.

This study followed the approach of dispersing and localizing carbon nanotubes (CNTs) in nanostructured domains of block copolymers (BCPs) by shortening the CNTs via ball milling. The aim was to selectively tune the electrical and mechanical properties of the resulting nanocomposites, e.g., for use as sensor materials. Multiwalled carbon nanotubes (MWCNTs) were ground into different size fractions. The MWCNT length distribution was evaluated via transmission electron microscopy and dynamic light scattering. The nanostructure of the BCPs and the glass transition temperatures of the PB-rich and PS phases were not strongly affected by the addition of CNTs up to 2 wt%. However, AFM and TEM investigations indicated a partial localization of the shortened CNTs in the soft PB-rich phase or at the interface of the PB-rich and PS phase, respectively. The stress-strain behavior of the solution-mixed composites differed little from the mechanical property profile of the neat BCP and was largely independent of CNT amount and CNT size fraction. Significant changes could only be observed for Young’s modulus and strain at break and may be attributed to CNT localization and small changes in morphology. For nanocomposites with unmilled CNTs, the electrical percolation threshold was less than 0.1 wt%. As the CNTs were shortened, the resistivity increased and the percolation threshold shifted to higher CNT contents. Composites with CNTs ground for 7.5 h and 13.5 h showed no bulk conductivity but significantly decreased surface resistivity on the bottom side of the films, which could be attributed to a sedimentation process of the grind and thereby highly compressed CNT agglomerates during evaporation.

Malabsorption syndrome aggravates calcium homeostasis impairment in chronic kidney disease patients

Abstract. Recent data on the role of digestive pathology in the progression of chronic kidney disease (CKD) remain scarce. Calcium homeostasis plays an important role in the progression of renal pathology, especially in patients with malabsorption syndrome (MAS).
 The research aimed to evaluate calcium homeostasis in CKD patients with MAS.
 Methods. In this cross-sectional observational study, 99 CKD patients with MAS were enrolled. The patients were divided into 4 groups according to the CKD stage and the presence of MAS. Group I included 25 patients with CKD stages 1 and 2 without MAS; Group II consisted of 26 patients with CKD stages 1 and 2, and MAS; Group ІІІ (n = 23) and Group ІV (n = 25) included patients with CKD stage 3 without and with MAS, respectively. According to the morphological study of in vivo biopsies of the small intestinal mucosa, mild and moderate morphological changes were observed among all patients. The levels of calcium, phosphorus, parathyroid hormone, osteocalcin, and calcitonin in the blood, as well as urinary calcium levels, were detected.
 Results. Pathological changes in calcium metabolism were observed among CKD patients with MAS. The severity of calcium homeostasis disorders was more evident among patients with CKD stage 3 compared with stages 1 and 2. Urinary calcium levels were reduced in the patients of Groups III and IV. No changes were detected in phosphorus levels. Changes in parathyroid hormone and osteocalcin are caused primarily by combined renal pathology with impaired renal calcium absorption.
 Conclusion. MAS in CKD patients leads to deep violations of calcium homeostasis resulting in rapid CKD progression and bone tissue violation.

Toxicological effects of the mixed iron oxide nanoparticle (Fe3O4 NP) on murine fibroblasts LA-9

ABSTRACT The increase in large-scale production of magnetic nanoparticles (NP) associated with the incomplete comprehensive knowledge regarding the potential risks of their use on environmental and human health makes it necessary to study the biological effects of these particles on organisms at the cellular level. The aim of this study to examine the cellular effects on fibroblast lineage LA-9 after exposure to mixed iron oxide NP (Fe3O4 NP). The following analyses were performed: field emission gun–scanning electron microscopy (SEM-FEG), dynamic light scattering (DLS), zeta potential, ultraviolet/visible region spectroscopy (UV/VIS), and attenuated total reactance-Fourier transform infrared (ATR-FTIR) spectroscopy analyses for characterization of the NP. The assays included cell viability, morphology, clonogenic potential, oxidative stress as measurement of reactive oxygen species (ROS) and nitric oxide (NO) levels, cytokines quantification interleukin 6 (IL-6) and tumor necrosis factor (TNF), NP uptake, and cell death. The size of Fe3O4 NP was 26.3 nm when evaluated in water through DLS. Fe3O4 NP did not reduce fibroblast cell viability until the highest concentration tested (250 µg/ml), which showed a decrease in clonogenic potential as well as small morphological changes after exposure for 48 and 72 hr. The NP concentration of 250 µg/ml induced enhanced ROS and NO production after 24 hr treatment. The uptake assay exhibited time-dependent Fe3O4 NP internalization at all concentrations tested with no significant cell death. Hence, exposure of fibroblasts to Fe3O4 NP-induced oxidative stress but not reduced cell viability or death. However, the decrease in the clonogenic potential at the highest concentration demonstrates cytotoxic effects attributed to Fe3O4 NP which occurred on the 7th day after exposure.

Dendrobium orchids carrying antisense ACC oxidase: small changes in flower morphology and a delay of bud abortion, flower senescence, and abscission of flowers.

Four Dendrobium Sonia 'Earsakul' lines were generated by insertion of one, two or three antisense copies of a Carica papaya gene encoding 1-aminocyclopropane-1-carboxylic acid oxidase (CpACO). Whole vegetative plants of the transgenic lines showed about 50% of the basal ethylene production rate, while the increase in ethylene production in floral buds during opening and open flowers prior to visible senescence was delayed. Detailed analysis of more than 100 parameters in flowering plants showed no effect of antisense ACO on plant morphology and coloration, except for shorter length and width of some of the sepals and petals. In intact plants the water-soaking of floral buds as well as bud abscission were delayed by ACO antisense, as was the time to senescence of open flowers. Pollen viability and pollen tube growth were not affected in the transgenic lines. In cut inflorescences placed in water, bud yellowing, bud water soaking, and bud abscission were considerably delayed by the antisense construct, while the life span of open flowers were increased and abscission of open flowers were delayed. It is concluded that the reduction of ACO activity affected the shape of some petals/sepals and delayed the abortion in floral buds, and the senescence and abscission of open flowers.

Improving the energetic efficiency of direct-contact membrane distillation in mining effluent by using the waste-heat-and-water process as the cooling fluid

The water footprint of the gold mining sector can be drastically diminished by adopting technologies that promote water reuse. In this context, membrane distillation (MD) is a promising alternative as it can produce a high-quality permeate while utilizing the effluent-waste heat, thus diminishing operational costs, as seen in previous studies. However, other issues regarding MD in this application are yet to be addressed such as the effect of feed pretreatment, pH adjustment, membrane stability, and cleaning, and the possibility of using the process water as a cooling solution. This study is thus aimed at addressing these questions. The obtained results showed that the adoption of ultrafiltration as a pretreatment without pH adjustment provided the best results for scale mitigation, while maintaining a rejection of over 99% for the main solutes. In addition, the use of the process water did not result in any changes in the process and was thus demonstrated as a feasible alternative. Furthermore, after 210 days, the chemical stability study showed small morphological changes in the membrane surface that did not affect its selectivity. Finally, the absence of mechanical pressure in the process resulted in the formation of a loosely adhered fouling layer that was easily removed via physical cleaning.

Early Exposure to THC Alters M-Cell Development in Zebrafish Embryos.

Cannabis is one of the most commonly used illicit recreational drugs that is often taken for medicinal purposes. The psychoactive ingredient in cannabis is Δ9-Tetrahydrocannabinol (Δ9-THC, hereafter referred to as THC), which is an agonist at the endocannabinoid receptors CB1R and CB2R. Here, we exposed zebrafish embryos to THC during the gastrulation phase to determine the long-term effects during development. We specifically focused on reticulospinal neurons known as the Mauthner cells (M-cell) that are involved in escape response movements. The M- cells are born during gastrulation, thus allowing us to examine neuronal morphology of neurons born during the time of exposure. After the exposure, embryos were allowed to develop normally and were examined at two days post-fertilization for M-cell morphology and escape responses. THC treated embryos exhibited subtle alterations in M-cell axon diameter and small changes in escape response dynamics to touch. Because escape responses were altered, we also examined muscle fiber development. The fluorescent labelling of red and white muscle fibers showed that while muscles were largely intact, the fibers were slightly disorganized with subtle but significant changes in the pattern of expression of nicotinic acetylcholine receptors. However, there were no overt changes in the expression of nicotinic receptor subunit mRNA ascertained by qPCR. Embryos were allowed to further develop until 5 dpf, when they were examined for overall levels of movement. Animals exposed to THC during gastrulation exhibited reduced activity compared with vehicle controls. Together, these findings indicate that zebrafish exposed to THC during the gastrula phase exhibit small changes in neuronal and muscle morphology that may impact behavior and locomotion.

In Vitro Study of Ethyl‐4‐(3,4.5‐trimethoxyphenyl)‐2,7,7‐trimethyl‐5‐oxo1,4,5,6,7,8‐hexahydroquinoline‐3‐carboxylate and Bovine Serum Albumin Using Multi‐Spectroscopic Techniques and Molecular Docking

AbstractThe binding of quinolone derivative ethyl‐4‐(3,4.5‐trimethoxyphenyl)‐2,7,7‐trimethyl‐5‐oxo1,4,5,6,7,8‐hexahydroquinoline‐3‐carboxylate (ETMTMHQC) to bovine serum albumin (BSA) is investigated by various spectroscopic methods and molecular docking analysis. The fluorescence quenching spectroscopic results show that ETMTMHQC bind to the protein BSA. The binding constant value is found to be 5.2 × 10−6 K (mol dm3). The thermodynamic parameter of the system shows increase in temperature with gradual decrease in Stern–Volmer quenching constant thereby indicating static quenching mode. Negative entropy and positive enthalpy indicate the hydrogen bonding interaction. The (r) distance between BSA and ETMTMHQC obtained from fluorescence resonance energy transfer is found to be 7.0 nm. The UV–visible spectra reveal the increase in absorbance on formation of BSA–ETMTMHQC complex. The CD spectral study indicates reduction of α‐helical structure in BSA and small changes in the tertiary structure of the protein. ETMTMHQC interacts strongly with BSA, and small changes in protein morphology are advised by molecular docking results. Moreover, docking results show that ETMTMHQC binds to BSA at ASN390 residue.

Naut Your Everyday Jellyfish Model: Exploring How Tentacles and Oral Arms Impact Locomotion

Jellyfish are majestic, energy-efficient, and one of the oldest species that inhabit the oceans. It is perhaps the second item, their efficiency, that has captivated scientists for decades into investigating their locomotive behavior. Yet, no one has specifically explored the role that their tentacles and oral arms may have on their potential swimming performance. We perform comparative in silico experiments to study how tentacle/oral arm number, length, placement, and density affect forward swimming speeds, cost of transport, and fluid mixing. An open source implementation of the immersed boundary method was used (IB2d) to solve the fully coupled fluid–structure interaction problem of an idealized flexible jellyfish bell with poroelastic tentacles/oral arms in a viscous, incompressible fluid. Overall tentacles/oral arms inhibit forward swimming speeds, by appearing to suppress vortex formation. Nonlinear relationships between length and fluid scale (Reynolds Number) as well as tentacle/oral arm number, density, and placement are observed, illustrating that small changes in morphology could result in significant decreases in swimming speeds, in some cases by upwards of 80–90% between cases with or without tentacles/oral arms.

Mirror Image Modeling of Acetabular Rim Thickness Differences in Patients With Unilateral Femoroacetabular Impingement Syndrome

PurposeTo use mirror imaging to identify the location and magnitude of difference in acetabular rim morphology between the symptomatic and unaffected acetabula in patients with symptomatic unilateral pincer-type or mixed femoroacetabular impingement syndrome (FAIS) using 1-dimensional models created with computed tomography (CT).MethodsCT scans of bilateral hips in 33 patients diagnosed with unilateral pincer-type or mixed FAIS were obtained. Three-dimensional bilateral hip models were constructed, and the unaffected hemipelvis was superimposed onto the symptomatic side to compare acetabular thickness. Protrusion of the symptomatic side was recorded, and rim morphology was divided into clock face quadrants to analyze the location of greatest magnitude of difference between affected and unaffected acetabula. Analysis of the quadrants was performed using analysis of variance with post hoc Bonferroni correction.ResultsThe study group consisted of more females (51.6%) than males, with an average age of 35.72 ± 7.8 years and an average body mass index of 24.3 ± 4.1 kg/m2. Of the 33 hips included, 14 were isolated pincer-type FAIS and 19 were mixed. The average preoperative symptomatic side lateral center edge angle was 37.5° ± 7.2° compared with 29° ± 5.1° on the asymptomatic side (P = .001). The symptomatic acetabular rim was on average 0.43 ± 0.18 mm thicker than the corresponding location on the unaffected rim. When the acetabulum was divided into clock face quadrants, the 12 to 3 o'clock position showed the greatest difference between symptomatic and unaffected sides (0.55 ± 0.18 mm) compared with the 3 to 6 o'clock position (0.4 ± 0.28 mm; P = .006), 6 to 9 o'clock (0.34 ± 0.07 mm; P < .001), and 9 to 12 o'clock (0.38 ± 0.03; P = .001).ConclusionsPatients with unilateral, symptomatic pincer-type or mixed FAIS show statistical differences in rim thickness between the affected and unaffected acetabula. Small changes in acetabular rim morphology on the order of ≤0.5 mm may be the difference between symptomatic FAIS and the unaffected hip.Level of EvidenceIV, case series.

Facile surface modification of ceramic membranes using binary TiO2/SiO2 for achieving fouling resistance and photocatalytic degradation

Inorganic surface modification was carried out using a TiO2/SiO2 sol–gel process to enhance photocatalytic activity and to mitigate fouling of alumina microfiltration membranes. Pristine alumina membranes were subjected to TiO2/SiO2 coating with varied TiO2 mole percentages. Upon the formation of the TiO2/SiO2 layer, small changes in the surface morphology, pore size, and specific surface area were detected. Particularly, as the pore size decreased with the decrease in TiO2 content, the pure water permeability also gradually diminished. By examining the binary TiO2/SiO2 compositions, the optimized conditions demonstrating both higher flux performance and greater photocatalytic activity were determined. Thus, the inorganic surface modification by TiO2/SiO2 coating could contribute significantly to the realization of self-cleaning ceramic membranes while extending the membrane cleaning cycle and accelerating productivity.

Irradiation of mung beans (Vigna radiata): A prospective study correlating the properties of starch and grains.

In this work, the effect of Gamma-irradiation was evaluated on the characteristics of mung bean (Vigna radiata) grains and starches, considering doses up to 5 kGy. For this purpose, the starch structure and properties were evaluated, as well as the grains' hydration, germination and cooking. The irradiation process was able to change the characteristics of both mung bean starches and grains. The starch structure was partially changed, presenting smaller molecules and small changes in the granule morphology. No alterations were observed in the starch X-ray diffraction pattern, while lower pH was achieved. Considering the starch properties, it was observed lower water retention ability at 75 °C, lower apparent viscosity, higher paste clarity and, in general, harder and less viscous gels. The ionizing radiation accelerated the hydration, reduced the germination capacity and improved cooking time of the mung bean grains. The results proved the efficacy of using ionizing radiation, at the doses applied in this work, to desirably modify the mung bean starch and grains.

Voltage stabilization of Sn-doped anatase for Li-ion battery applications predicted by DFT calculations

Abstract We have studied the effects of Sn substitutional doping in anatase using a screened exchange density functional. We observe almost no change in the electronic structure of anatase and only small changes in morphology due to Sn doping. Upon Li insertion at different concentrations, the systems are found to be indirect bandgap semiconductors with a Ti dominated peak at the edge of the valence region. As Li is inserted in the structure, there is a change in the morphology from tetragonal to orthorhombic. However, the tetragonal structure is recovered for the maximum Li intake corresponding to stoichiometry of Li1Sn1/16Ti15/16O2. Importantly, in contrast to pristine anatase, we find that Sn doping stabilizes the voltage profile of Li insertion at high Li concentrations which allows Li intake beyond what is possible in pristine anatase.

Snap-jaw morphology is specialized for high-speed power amplification in the Dracula ant, Mystrium camillae.

What is the limit of animal speed and what mechanisms produce the fastest movements? More than natural history trivia, the answer provides key insight into the form–function relationship of musculoskeletal movement and can determine the outcome of predator–prey interactions. The fastest known animal movements belong to arthropods, including trap-jaw ants, mantis shrimp and froghoppers, that have incorporated latches and springs into their appendage systems to overcome the limits of muscle power. In contrast to these examples of power amplification, where separate structures act as latch and spring to accelerate an appendage, some animals use a ‘snap-jaw’ mechanism that incorporates the latch and spring on the accelerating appendage itself. We examined the kinematics and functional morphology of the Dracula ant, Mystrium camillae, who use a snap-jaw mechanism to quickly slide their mandibles across each other similar to a finger snap. Kinematic analysis of high-speed video revealed that snap-jaw ant mandibles complete their strike in as little as 23 µsec and reach peak velocities of 90 m s−1, making them the fastest known animal appendage. Finite-element analysis demonstrated that snap-jaw mandibles were less stiff than biting non-power-amplified mandibles, consistent with their use as a flexible spring. These results extend our understanding of animal speed and demonstrate how small changes in morphology can result in dramatic differences in performance.

Limited field radiation therapy results in decreased bone fracture toughness in a murine model.

Fragility fractures are a well-known complication following oncologic radiotherapy, and it is suspected that radiation-induced embrittlement of bone within the treatment field may contribute to fracture risk. To explore this phenomenon, a mouse model (BALB/cJ) of fractionated, limited field, bilateral hindlimb irradiation (4x5 Gy) was used. The effects of radiation on femoral (cortical) bone fracture toughness, morphology, and biochemistry—including advanced glycation end products (AGEs)—were quantified and compared to Sham group samples prior to irradiation and at 0, 4, 8, and 12 weeks post-irradiation. Additionally, alterations to bone fracture toughness mediated directly by radiation (independent of cellular mechanisms) were determined using devitalized mouse cadaver femurs. Finally, the contribution of AGEs to reduced fracture toughness was examined by artificially ribosylating mouse femurs ex vivo. These data demonstrate that in vivo irradiation results in an immediate (-42% at 0 weeks, p < 0.001) and sustained (-28% at 12 weeks, p < 0.001) decrease in fracture toughness with small changes in morphology (-5% in cortical area at 12 weeks), and minimal changes in bone composition (tissue mineral density, mineral:matrix ratio, and AGE content). Irradiation of devitalized femurs also reduced fracture toughness (-29%, p < 0.001), but to a lesser extent than was seen in vivo. While artificial ribosylation decreased fracture toughness with time, the extent of glycation needed to induce this effect exceeded the AGE accumulation that occurred in vivo. Overall, hindlimb irradiation induced a substantial and sustained decrease in bone fracture toughness. Approximately half of this decrease in fracture toughness is due to direct radiation damage, independent of cellular remodeling. Collagen glycation in vivo was not substantially altered, suggesting other matrix changes may contribute to post-radiotherapy bone embrittlement.

Congenital Cervical Vertebral Malformation in Lambs

Background: The occurrence of congenital defects in the sheep is estimated to be between 0.2% and 2%. For congenital anatomical alterations, diagnostic imaging allows objective understanding and evaluation, and is a great aid in the formulation of clinical decisions. Most of these anomalies are diagnosed by radiography; but computed tomography (CT) can provide important additional information. In the current literature there are no descriptions of the use of radiography andCT for a more detailed evaluation of the anatomical structures in cases of congenital cervical malformations in lambs. The objective of this study is to report the clinical, radiographic and tomographic findings in two cases of congenital cervical vertebral malformation in lambs.Cases: Two lambs with cervical morphological alterations since birth were attended. A 4-month-old mixed-breed lamb, weighing 11 kg, with lateroventrocaudal deviation of the neck was observed to the right side, not yielding to the attempt of repositioning. The owner reported that these changes were identified since birth, leading to difficulties in suckling colostrum, necessitating artificial feeding. With the growth of the animal, worsening of the cervical deviation resulted in the impossibility of grazing. The radiographs of the cervical spine identified marked scoliosis, and the axis presented small dimensions and morphological changes with a slight loss of atlantoaxial articular relationship. Spondylopathies were detectedalong the cervical spine. Other lamb of the Lacaune breed, weighing 4.2 kg, was presented shortly after birth with changes in the shape and posture of the neck, difficult locomotion and in sternal decubitus. The owner reported that the lamb came from a twin eutocic birth, with the other lamb being apparently normal. The animal was unable to ingest the colostrum, in which the sheep was milked and colostrum was offered through a bottle. Lateroventrocaudal deviation of the neck to the left side did not yield to the repositioning attempt, the mandible also presented left lateral deviation. The radiographs of the cervical spine showed morphological changes in atlas, and it was not possible to delimit its wings; itwas also observed that the dorsal blade was parallel to the spinal process of the axis. The presence of a hypoattenuating linear left lateral image of the dorsal arch and a right ventro-lateral aspect of the atlas body was identified with slightly irregular and sclerotic margins, suggesting fracture lines. The body of the axis presented a conformational alteration withirregular contours and a large free fragment in the cranial aspect, suggestive of being the odontoid process, with rotation and deviation to the left in relation to the atlas. The right lateral cranial articular process of the third cervical vertebra (C3) presented a conformational change and important lateral rotation of the axis. Mild stenosis of the medullary canal was observed in the segment adjacent to C3. The euthanasia was recommended.Discussion: Congenital cervical malformations in sheep are rare in the literature and may lead to serious decrease in the quality of life of the animals. Computed tomography was superior to radiography in morphological evaluation in cases of congenital cervical malformations in sheep. However, both diagnostic methods were important to establish the best clinical behavior. The etiology of most congenital malformations is unknown, simply because of the complexity of the mechanismsthat lead to the formation of an abnormality. The isolated episodes of this anomaly, in the herd without previous alterations, suggest a non-infectious cause, probably similar among the cases, but not established. The information presented can be used to validate clinical reasoning in future cases similar to those described, where imaging features are not available.Keywords: anomalies, fetus, radiography, computed tomography.