Longitudinal Fibers Research Articles

The effect of loading rate on the compression properties of carbon fibre-reinforced epoxy honeycomb structures

The effect of varying strain rate on the compression strength and energy absorption characteristics of a carbon fibre-reinforced plastic honeycomb core has been investigated over a wide range of loading rates. The honeycombs were manufactured by infusing an epoxy resin through a carbon fibre fabric positioned in a dismountable honeycomb mould. The vacuum-assisted resin transfer moulding technique yielded honeycomb cores of a high quality with few defects. Compression tests were undertaken on single and multiple cells and representative volumes removed from the cores in order to assess how the compression strength and specific energy absorption vary with test rate. Crushing tests over the range of strain rates considered highlighted the impressive strength and energy-absorbing response of the honeycomb cores. At quasi-static rates of loading, the compression strength and specific energy absorption characteristics of the unidirectional samples exceeded those of the multidirectional cores. Here, extensive longitudinal splitting and fibre fracture were the predominant failure mechanisms in the cores. For all three stacking sequences, the single-cell samples offer higher compression strength than their five-cell counterparts. In contrast, the specific energy absorption values were found to be slightly higher in the five-cell cores. The experiments highlighted a trend of increased compression strength with loading rate in the multidirectional samples, whereas the strength of the [0°]4 samples was relatively insensitive to strain rate. Finally, the energy absorbing capacity of all structures studied was found to be reasonably constant at increasing rates of strain.

Sex differences in mitochondrial Ca2+ handling in mouse fast-twitch skeletal muscle in vivo.

We investigated sex differences in mitochondrial Ca2+ handling properties in mouse fast-twitch skeletal muscle. Changes in cytoplasmic Ca2+ concentration ([Ca2+]cyto) were measured in vivo using tibialis anterior muscles from male and female mice. The muscles were exposed to increasing concentrations of cyclopiazonic acid [CPA; sarcoplasmic reticulum (SR) Ca2+-ATPase inhibitor] (from 10 to 30 to 50 μM at 10 min intervals). Thirty minutes after treatment, [Ca2+]cyto was increased by 31.6 ± 2.0% and 13.5 ± 4.5% of initial [Ca2+]cyto in male and female muscles, respectively, and there was a significant difference between sexes. However, muscle preincubation for 5 min with 10 μM carbonyl cyanide-4-(trifluoromethoxy) phenylhydrazone (an inhibitor of mitochondria Ca2+ uptake) eradicated this difference between sexes with respect to the CPA-induced [Ca2+]cyto increase. Both intermyofibrillar mitochondrial number and volume, assessed in longitudinal fiber sections, were higher in females compared with males (mitochondria number: 13.1 ± 1.0 in males vs. 19.9 ± 2.3 in females; mitochondrial volume: 0.034 ± 0.004 μm3/μm3 fiber volume in males vs. 0.066 ± 0.008 μm3/μm3 fiber volume in females, both P < 0.05). There were no sex differences in the content of SR Ca2+-ATPase, mitochondrial Ca2+ uniporter, mitofusin (Mfn) 1, or Mfn2. These results suggest that 1) mitochondrial Ca2+ uptake ability is greater in female than male myocytes, and 2) this superior Ca2+ uptake ability of female myocytes is due, partly, to the higher intermyofibrillar mitochondrial content but not to the expression of mitochondrial proteins related to mitochondrial Ca2+ uptake.NEW & NOTEWORTHY This investigation presents evidence that female versus male fast-twitch muscle exhibits a greater mitochondrial calcium ion uptake capability that is partly conferred by the higher intermyofibrillar mitochondrial volume density.

429 Right ventricular longitudinal and radial fiber contractility in patients undergoing mitral valve surgery: a PREPARE-MVR substudy

Abstract Severe mitral regurgitation results in significant hemodynamic demands of not only the left, but the right ventricle (RV) as well. Increased pulmonary pressures and consequential pressure overload of the RV induces complex remodeling, which can be partially restored by mitral valve repair/replacement (MVR). MVR is associated with marked changes of RV deformation, however, the clinical significance of these changes is not well estabilished. The PREPARE-MVR study (PRediction of Early PostoperAtive Right vEntricular failure in Mitral Valve Replacement/Repair patients) aims to determine parameters, which may predict the perioperative risk of acute RV failure. In this current substudy, our aim was to determine the changes of RV global, longitudinal and radial fiber contractility before and following MVR. Our study group consisted of 27 MVR patients (mean age: 64 ± 12 years, m/f: 19/8). Transthoracic 3D echocardiography was performed before the operation and following intensive care unit discharge. 3D beutel model of the RV was created and RV end-diastolic volume index (EDVi) among with RV ejection fraction (RVEF) were calculated using commercially available software. For in-depth analysis of RV mechanics, we have decomposed the motion of the RV using our custom software (ReVISION) to determine longitudinal (LEF) and radial ejection fraction (REF). Right heart catheterization was also performed before MVR and 24 hours after MVR as well to measure pulmonary arterial mean systolic pressure (mPAP), pulmonary arterial wedge pressure (PAWP) and RV stroke work index (RVSWi). Using the aforementioned parameters, we have calculated RV longitudinal (longRVSWi) and RV radial stroke work index (radRVSWi), which represent RV longitudinal and radial fiber contractility. RV morphology did not change significantly according to RVEDVi (preop vs. postop: 71 ± 17 vs. 72 ± 20 mL/m², p = NS). RVEF slightly decreased after MVR (50 ± 6 vs. 48 ± 7 %, p &amp;lt; 0.05), however, RV motion pattern markedly changed. Postoperative LEF was significantly lower compared to preoperative values (25 ± 6 vs. 16 ± 6%, p &amp;lt; 0.0001), among with an increase in REF (21 ± 7 vs. 27 ± 7%, p &amp;lt; 0.01). As expected, mPAP and PAWP decreased in response to MVR (mPAP: 30 ± 10 vs. 25 ± 7 mmHg; PAWP: 19 ± 7 vs. 13 ± 3 mmHg, both p &amp;lt; 0.01). Global RV contractility decreased after surgery (RVSWi: 603 ± 355 vs. 474 ± 251 mmHg*mL/m², p &amp;lt; 0.05). While RV longitudinal contractility also significantly reduced (longRVSWi: 289 ± 179 vs. 166 ± 122 mmHg*mL/m², p &amp;lt; 0.001), radial contractility was maintained following MVR (radRVSWi: 240 ± 141 vs. 261 ± 144 mmHg*mL/m², p = NS). MVR is associated with marked changes of RV function and hemodynamics. RV longitudinal and radial contractility have distinct response to surgery, which may be important in postoperative patient management. The PREPARE-MVR study aims to examine the role of preoperative RV mechanics in clinical outcome.

Morphometry and Frequency of the Pyramidalis Muscle in Adult Humans: A Pyramidalis Muscle's Anatomical Analysis

OBJECTIVES:To verify the pyramidalis muscle’s frequency (bilaterality, unilaterality, or absence) and morphometry (length of the medial border and width of its origin/base) in a sample of the Brazilian population and the anthropometric influence.METHODS:Dissection of 30 cadavers, up to 24h post-mortem.RESULTS:The pyramidalis muscle was present bilaterally and unilaterally in 83.33% and 3.33% of the cadavers, respectively, and absent in 13.33%. The muscles on the right and left sides were symmetrical in length but not in width; the pyramidalis muscles of men were longer, while those of the women were wider. We also found that there was greater variation in the dimensions (length and width) of the men’s muscles. Finally, in this sample of the Brazilian population, the pyramidalis muscle’s unilaterality was more prevalent than in other populations, and its complete absence was less prevalent.CONCLUSIONS:There were no cases of muscle duplication in one or both sides, as described in some studies. Despite all of its morphometric variation, the pyramidalis muscle maintained its triangular shape with longitudinal fibers in every case. Furthermore, no statistically significant correlation was noted between the muscles’ dimensions and person’s age, height, weight, or gender.

Shear tests on GFRP reinforced concrete beams

This paper aims to investigate the shear failure mechanisms in beams reinforced with longitudinal and transverse glass fibre reinforced polymer bars. It is a part of comprehensive research on shear in concrete beams reinforced with steel and GFRP bars. The experimental program is composed of six real-scale single-span, simply-supported T-cross section concrete beams. The beams varied mainly with respect to the longitudinal reinforcement ratio (2.91% and 3.69%), bar diameter (25mm and 28mm, respectively) and transverse reinforcement ratio (0.16% and 0,33%). The paper presents test results, cracking patterns, failure modes and an analysis of the influence of variable parameters on the shear behaviour of elements.

P1547 Left ventricular papillary muscle strain as an indicator of hypertrophic cardiomyopathy

Abstract Background Although recognized as part of the mitral valve complex, few studies have assessed the left ventricular papillary muscle. We confirmed during autopsy that papillary muscle consists of longitudinal aligned muscle fibers, and that the papillary muscle originated from the left ventricular oblique muscle. Therefore, papillary muscle contraction was considered only in the longitudinal direction. Purpose We previously reported that left ventricular papillary muscle strain (LV-PMS) in 100 patients without organic heart disease was correlated with multiple left ventricular function assessment parameters. This study aimed to determine whether left ventricular papillary muscle strain (LV-PMS) in patients with hypertrophic cardiomyopathy (HCM) is correlated with left ventricular function parameters as in non-HCM patients. Methods We measured left ventricular papillary muscle strain (LV-PMS) between two points on papillary muscles except where chordae adhere and the left ventricular wall, and compared values between patients without organic heart disease and with hypertrophic cardiomyopathy (HCM). Among 1,344 patients who were assessed by echocardiography at our hospital between January and June 2018, we selected 42 (mean age, 68.9 ± 17.4 years; male, 67%) who did not have coronary heart disease and in whom left ventricular papillary muscle contraction strain (LV-PMS) could be determined. Obvious anterior and posterior papillary muscles were evaluated. We also analyzed age, EF, e’, s’, E/e’, E/A, left atrial volume index (LAV-I) and global longitudinal strain (GLS) as possibly relevant factors. Results Among the 42 patients, 22 (52%) and 17 (40%) had hypertension and HCM, respectively. We measured the strength of linear associations among paired variables (LV-PMS, age, EF, e’, s’, E/e’, E/A, LAV-I and GLS) using Pearson product-moment correlation coefficients. Age (r = 0.64), e’ (r = -0.76), s’ (r = -0.61), LAV-I (r = 0.61) and GLS (r = 0.57; all p &amp;lt; 0.001), as well as E/e’ (r = 0.44, p &amp;lt; 0.05) significantly correlated in patients without HCM, whereas only GLS correlated in patients with HCM (r = 0.723, p &amp;lt; 0.001). One-way analyses of variance showed that LV-PMS values significantly differed only among patients without HCM when categorized according to age &amp;lt; 50, ≥ 50 &amp;lt; 75 and &amp;gt; 75 years (p &amp;lt; 0.001), whereas these values significantly differed in all patients (p &amp;lt; 0.05) when categorized according to GLS &amp;lt; -20%, ≥ -20 to &amp;lt; -15% and &amp;gt; -15%. Conclusions We found that LV-PMS correlated with five factors including age in patients without HCM, but only with GLS in those with HCM. Despite the small study cohort, we considered that LV-PMS and GLS would be useful for evaluating left ventricular function in patients with HCM.

Effect of small ply angle variation in tensile and compressive strength of woven GFRP composite: Application of two parameter Weibull distribution

This paper demonstrates the effect of small ply angle variation in tensile and compressive strength of woven Glass Fiber Reinforced Polymer (GFRP) composites. Four different plies of (0/90)4, (±5°)4, (±10°)4, (±15°)4 manufactured by hand lay-up followed by the press molding machine. Samples for the tensile and compressive tests were prepared according to ASTM D3039 and ASTM D3410 standards. Three samples of each laminate were tested on a Universal Testing Machine (UTM) at a steady crosshead speed of 1 mm/min. A digital microscope was used for tracking the sample damage pattern. It was observed that fiber orientation in laminates affects the tensile and compressive strength. Fibers ruptured during tensile testing of specimens and in compressive testing, samples failed due to the separation of longitudinal fibers. The experimental results showed that (0/90)4 ply showed the maximum tensile strength and compressive strength followed by (±5°)4, (±10°)4, (±15°)4. Weibull distribution analysis was used for statistical estimation of the tensile and compressive life of specimens.

Linear Distribution Principle for Sheet Forming Using Continuous Roll Forming Process

Continuous roll forming (CRF) process utilizes two reconfigurable rollers as forming tools to manufacture 3D surface part. In order to investigate the longitudinal deformation of 3D curved surface part, the detailed mathematical methodology using a geometrical relationship is analyzed and described. The results show that the necessary condition for generating longitudinal bending deformation is the linear distribution of the longitudinal fiber. The deformation characteristics of CRF studied by simulation confirm that the ideal longitudinal deformation is generated when the distribution of longitudinal fibers satisfy the linear distribution principle, the maximum length difference of longitudinal fibers is the major factor determining the longitudinal curvature radius of formed part, and increasing maximum length difference of longitudinal fibers incurs an increasing longitudinal curvature. In addition, 3D surface parts with different longitudinal curvature were prepared by CRF process, which had verified the proposed linear distribution principle.

材料力学中梁内单根纵向纤维弯曲变形研究

材料力学中梁内单根纵向纤维弯曲变形研究

Velocity Vector Imaging technology and standard echocardiography in evaluation of left ventricular function in patients with coronary artery disease before and after coronary bypass surgery

Aim. To study strain and strain rate dynamics the left ventricle (LV) myocardium fibers in patients with ischemic heart disease after coronary artery bypass grafting (CABG) in the early and late periods.Material and methods. The dynamics of strain (S) and strain rate (SR) of longitudinal, circular and radial fibers in 148 patients (in 2646 LV segments) before and on the 12th day after CABG was studied using Velocity Vector Imaging technology. In the long-term (6, 12 and 24 months) 40 patients (720 LV segments) were examined.Results. A positive dynamics of SR longitudinal fibers (p = 0.0002) was on the 12th day after CABG. Weak and medium correlation was between S and SR radial (R = –0.56; R = –0.52) and circular fibers with LDG-1 and duration of aortic clamping. In the long term, patients with complaints showed a decrease in global deformation properties in the coronary artery areas. The stable result of improvement S and SR longitudinal and circular fibers and SR radial fibers was obtained in segments with initially low deformation properties.Conclusions. The use of Velocity Vector Imaging technology allows to estimate the dynamics of LV fibers deformation parameters in early and long-term periods. In the early period after CABG was a positive dynamic only from the global SR longitudinal fibers. In the long-term global deformation parameters of longitudinal and circular fibers was decrease in in the area of the coronary arteries. In the long-term was a significant improvement of the deformation parameters of segments with initially low deformation properties.

Modeling of tensile behavior of hybrid GFRP-steel reinforced concrete chords

Arranging a hybrid combination of longitudinal fiber reinforced polymer (FRP) bars and longitudinal steel bars in the tensile zone of a concrete beam is able to sufficiently exploit the superior properties of both FRP and steel materials to achieve a satisfactory ductility level. As the foundation of analysis and design of hybrid FRP-steel reinforced concrete (RC) members, study of tensile behavior of concrete chords with FRP-steel reinforcement is essential and necessary. In this paper, the average crack spacing of hybrid (Glass Fiber Reinforced Polymer-GFRP and steel) RC chords is analytically estimated. Subsequently, the Tension Chord Model (TCM) is extended to predict the tensile behavior of hybrid GFRP-steel RC chords. Finally, the presented models are effectively validated by experimental results of concrete chords reinforced with GFRP bars and steel bars in different combinations available in the literature, and detailed discussions about analytical and experimental results are also performed.

The impact of age, mineralization, and collagen orientation on the mechanics of individual osteons from human femurs

Osteons are the end product of cortical bone remodeling. Changes in their mechanical properties may be an indicator of overall bone health. Aszenci and Bonucci first evaluated the compressive properties of individual osteons in 1968. However, these results have never been independently validated and technological advances allow for further investigation of osteon mechanics. In the present study, an experimental protocol was established such that osteons ~250 µm in diameter were successfully extracted from human cortical bone (males, ages 93 and 64) and loaded in compression. Both micro-computed tomography and second harmonic generation (SHG) microscopy imaging methods were incorporated into the protocol to improve the structural and compositional assessment of each osteon. Further, a high-resolution videography system was used to monitor the osteons during mechanical testing, permitting insight into deformation mechanisms in situ. The results show that the older donor osteons (male, age 93 (n = 13)) were stiffer (p = 0.04) and more highly mineralized (p = 0.03), while the younger donor osteons (male, 64 (n = 14)) exhibited more heterogeneity in the measured mechanical properties with the presence of both stiff and more compliant osteons. SHG intensity indicated predominantly longitudinal fiber alignment for all osteons while the videography data revealed three distinct failure modes and confirmed that whitening observed during yielding of macroscale bone specimens represents failure at the local level. The stiffness and strength of the younger donor osteons were heavily dependent on the gross structure of the osteon, while these properties were dominated by collagen orientation in the older donor osteons.

Behavior of fetal longitudinal myocardial fibers assessed by speckle tracking to obtain strain and strain rate values for low-risk pregnancies.

Objective To analyze the behavior of fetal longitudinal myocardial fibers assessed by speckle tracking (STE) after fetal viability. Methods A cross-sectional study was performed in 156 women with normal singleton pregnancies from 22 to 31 weeks of gestation. Strain (S) and strain rate (SR) values were measured in both ventricles during the fetal cardiac cycle. The population was divided into five gestational age groups based on 2-week intervals. The correlations of maternal variables with the S and SR variables and intra-observer analysis were performed. Results There was a significant difference in the S and SR values of the left ventricle (LV) among the gestational age groups (P = 0.007). Significantly higher S and SR values were observed in early age groups demonstrating reductions in LV S and SR values at 26 weeks, followed by stabilization. For the right ventricle (RV), there was no significant difference between gestational age groups. Significant intra-observer agreement was observed for S values of the RV (P = 0.008) and LV (P = 0.0004) and SR values of the RV (P = 0.0001) and LV (P = 0.015). Conclusion Decreases in the S and SR values of the LV occurred after 26 weeks, followed by stabilization. No significant difference was observed in the S or SR value of the RV among the gestational age groups, and no significant association of any maternal variable evaluated with S and SR values was observed. Significant intra-observer agreement was obtained among the results.

Biomechanical and microstructural characterisation of the porcine stomach wall: Location- and layer-dependent investigations

The mechanical properties of the stomach wall help to explain its function of storing, mixing, and emptying in health and disease. However, much remains unknown about its mechanical properties, especially regarding regional heterogeneities and wall microstructure. Consequently, the present study aimed to assess regional differences in the mechanical properties and microstructure of the stomach wall. In general, the stomach wall and the different tissue layers exhibited a nonlinear stress-stretch relationship. Regional differences were found in the mechanical response and the microstructure. The highest stresses of the entire stomach wall in longitudinal direction were found in the corpus (201.5 kPa), where food is ground followed by the antrum (73.1 kPa) and the fundus (26.6 kPa). In contrast, the maximum stresses in circumferential direction were 39.7 kPa, 26.2 kPa, and 15.7 kPa for the antrum, fundus, and corpus, respectively. Independent of the fibre orientation and with respect to the biaxial loading direction, partially clear anisotropic responses were detected in the intact wall and the muscular layer. In contrast, the innermost mucosal layer featured isotropic mechanical characteristics. Pronounced layers of circumferential and longitudinal muscle fibres were found in the fundus only, whereas corpus and antrum contained almost exclusively circumferential orientated muscle fibres. This specific stomach structure mirrors functional differences in the fundus as well as corpus and antrum. Within this study, the load transfer mechanisms, connected with these wavy layers but also in total with the stomach wall’s microstructure, are discussed. Statement of significanceThis article examines for the first time the layer-specific mechanical and histological properties of the stomach wall attending to the location of the sample. Moreover, both mechanical behaviour and microstructure were explicitly match identifying the heterogeneous characteristics of the stomach. On the one hand, the results of this study contribute to the understanding of stomach mechanics and thus to their functional understanding of stomach motility. On the other hand, they are relevant to the fields of constitutive formulation of stomach tissue, whole stomach mechanics, and stomach-derived scaffolds i.e., tissue-engineering grafts.

Excessive Dynamic Airway Collapse Masquerading as Asthma

Expiratory central airway collapse (ECAC) includes 2 different pathophysiologic entities, excessive dynamic airway collapse (EDAC) and tracheobronchomalacia (TBM). We present a chronic cough case with history of asthma that was diagnosed as EDAC by dynamic bronchoscopy and its improvement with stent trial. A 71-year-old never-smoker man with past medical history mainly relevant for chronic rhinitis, gastroesophageal reflux, and chronic opioid therapy secondary to chronic back pain presented to clinic for frequent “acute bronchitis” and pneumonia episodes requiring prolonged intravenous antibiotics and systemic corticosteroids. His respiratory symptoms included persistent and productive cough with occasional wheezing. Pulmonary function test results were normal with no obstructive or restrictive pattern, and a normal diffusion capacity. FEV1 was 2.36 L (83% of predicted), forced vital capacity was 3.21 L (86% of predicted), FEV1/forced vital capacity was 73.4 (96% of predicted), maximum vital capacity was 3.73 L (100% of predicted), and forced expiratory flow at 25% to 75% of forced vital capacity was 1.71 (78% of predicted). Flow-volume loop was normal (Figure 1). No bronchodilator or methacholine challenges were performed. Laboratory workup was relevant for an absolute eosinophil count of 250 cells/μL and total IgE level of 575 kU/L. The patient had no significant improvement with high-dose inhaled corticosteroids/long-acting inhaled beta-agonists, long-acting inhaled anticholinergics, and omalizumab. Additional evaluation was performed in consideration of an alternative diagnosis. Chest computed tomography demonstrated some areas of mucous plugging over lower lobes with minimal bronchiectasis. Dynamic bronchoscopy revealed severe EDAC (>90% collapse) at the mid and distal trachea (Figure 2, A and B), left (Figure 2, D) and right main stem (Figure 2, C) bronchus, and bronchus intermedius. He underwent stent trial with uncovered self-expanding metallic stents (Figure 2, E and F) with subsequent improvement (Figure 2, E and F) of his Modified Medical Research Council dyspnea scale score by 1 point, his St George's Respiratory Questionnaire score by 4 points, and Cough Specific Quality of Life Questionnaire score by more than 10 points. There are plans for tracheobronchoplasty; however, the patient was lost to follow-up.Figure 2(A) Distal trachea (DT), left main bronchus (LMB), right main bronchus (RMB) on inspiration. (B) DT, LMB, and RMB, on forced expiration demonstrating severe EDAC. (C) RMB on forced expiration with severe EDAC. (D) LMB on forced expiration with severe EDAC. (E) DT, LMB, and RMB after stent placement on inspiration. (F) DT, LMB, and RMB after stent placement on expiration. Note the significant improvement and minimal posterior wall collapsed pointed by the arrow after the stent placement.View Large Image Figure ViewerDownload Hi-res image Download (PPT) This case emphasizes that EDAC should be considered in the differential diagnosis in chronic cough evaluations, especially in patients with physician-diagnosed asthma who are not responding to standard medical therapy. Around 1 in every 3 patients with physician-diagnosed asthma does not have asthma after objective airway limitation testing.1Aaron S.D. Vandemheen K.L. FitzGerald J.M. Ainslie M. Gupta S. Lemiere C. et al.Reevaluation of diagnosis in adults with physician-diagnosed asthma.JAMA. 2017; 317: 269-279Crossref PubMed Scopus (275) Google Scholar Airway clearance physiotherapy is always implemented in patients with significant ECAC. All patients with severe ECAC should be considered for a stent trial. It is important to highlight that stent trial is not an effective long-term solution for ECAC. Airway stents are removed after 7 to 10 days while new testing is performed to assess objective improvement in testing and symptoms that will justify surgical correction with a tracheobronchoplasty. The differentiation between EDAC and TBM may alter the surgical approach. EDAC refers to an excessive forward displacement of the posterior tracheal wall (membranous portion) due to weakness and atrophy of the longitudinal elastic fibers. The use of this term should only be meant to describe an abnormality in the posterior or membranous portion of the tracheobronchial tree. TBM is a term that should be used to describe an abnormality in the anterior/lateral (cartilaginous) portion of the tracheal wall. Both terms are independent to the longitudinal extension of the disease and root more in their different pathophysiology.2Kheir F. Fernandez-Bussy S. Gangadharan S.P. Majid A. Excessive dynamic airway collapse or tracheobronchomalacia: does it matter?.Arch Bronconeumol. 2019; 55: 69-70Crossref PubMed Scopus (6) Google Scholar The clinical presentation has a wide spectrum ranging from asymptomatic to severe life-limiting airway symptoms such as dyspnea, cough, and sputum retention. The actual prevalence in the general population is unknown.

Observation on the distribution of nerve fibers and neural cells morphology in Aspidogaster conchiola

To understand the distribution of nerve fibers and the types of neural cells in Aspidogaster conchiola. Whole worms were subjected to silver staining, histochemical staining and hematoxylin-eosin (HE) staining, and the nervous systems of the worms were observed. There were 3 types of neural cells in the worm head near the cerebral ganglion, including unipolar, bipolar and multipolar neurons, which were divided into 7 types according to the morphology. There was a nerve network on the surface of pharynx and intestinal tract, as well as the reproductive organ, including testis, ovary, lower uterus and penis sac. The nerve network was consisted of circular and longitudinal nerve fibers, and the structure of the nerve network around the mouth was similar to central nerve. The structure of the A. conchiola central nervous system is very complicated, and the neural networks may be associated with the physiologic activity of the worm. Different neural cells may have diverse functions.

23-G trocar-assisted cyclopexy: scleral sparing method as a new modality for large cyclodialysis repair

Cyclodialysis cleft results from separation of longitudinal ciliary muscle fibres from the scleral spur. The separation increases the uveoscleral outflow, leading to severe hypotony. Complexity in managing such condition relies on the extent of the injury and its collateral damage. We reported an alternative method of surgical repair for large cyclodialysis. The procedure was less invasive utilizing a scleral sparing technique. A 66-year-old gentleman presented with severe blunt trauma injury to the globe secondary to shuttlecock injury while playing badminton. He presented with a vision of hand motion. There was hyphaema (filling up half of the anterior chamber), complete posterior dislocation of the crystalline lens, and minimal vitreous haemorrhage. Posterior globe rupture was excluded with further imaging of the orbit. Despite significant amount of hyphaema, intraocular pressure (IOP) remained low several days post injury. Further investigations revealed the presence of almost 270° of cyclodialysis. Surgical repair was indicated. In order to avoid an extensive cut on the sclera, the treating surgeon decided to explore a less invasive method utilizing a small gauge vitrectomy trocar. The main instruments used were the trocar, a straight prolene needle, and a bent 25-G needle. The direction of trocar insertion plays a pivotal role in bringing the detached ciliary body back to its original position. The simplified technique did not require the creation of a scleral flap or direct visualization of the ciliary body. The technique was fast and less invasive, with early improvement of IOP post intervention.

Experimental study of the uniaxial stress-strain relationships of parallel strand bamboo in the longitudinal direction

Parallel strand bamboo has extensive potential applications as a structural material for construction. Studying longitudinal stress-strain relationships is essential as a means to build a constitutive law for parallel strand bamboo composites and to conduct an inelastic analysis for structural members constructed by this material. For this reason, failure modes and the damage mechanisms were investigated for tension and compression in parallel strand bamboo composites in the longitudinal direction. An analytical stress-strain formula for the parallel strand bamboo composites was developed for tension and compression related calculations. Tensile failure was caused by the damage of the longitudinal fibers and showed brittle characteristics. The compressive failure resulted from the buckling of the fibers near the damage area. In addition, three types of failure modes were observed; longitudinal buckling failure, compressive-shearing failure, and longitudinal crush failure. The stress-strain relationship in the longitudinal direction of parallel strand bamboo composites exhibited linear behaviour for tension. However, the stress-strain relationship for compression remained linear within the proportional limit, while becoming nonlinear, which can be simulated by a quadratic polynomial, once the stress exceeded the limit. The experimental data agreed well with the model predictions, showing that the present model had high prediction accuracy.

Detailed Pharmacognostical and Phytochemical Screening of Stem and Stem Bark of Ficus semicordata Buch.-Ham. Ex sm. - An Extra Pharmacopoeial Drug of Ayurveda

Introduction: Stem bark of Bhumi udumbara (Ficus semicordata Buch.-Ham. ex Sm.) is used traditionally in the treatment of leprosy, ulcer, dysentery, wound, pregnancy, complaints of gastric, liver, bladder and various disorders. In present study, stem and stem bark of F. semicordata are explored for their microscopic including powder microscopy, physiochemical and preliminary phytochemical aspects. Materials and Methods: Stem and stem bark of the plant, after proper authentication by BSI Kolkata, were evaluated following standard procedures. Results: Stem is hard, cylindrical, cut pieces measures about 10 - 25cm in length and 0.4 – 0.8 cm in diameter. Diagrammatic transverse section of stem shows outer cork followed by wide parenchymatous cortex with prismatic and rhomboidal crystals, starch grains and tannin content. Powder light brown in colour; odour woody; taste tasteless to astringent; texture fibrous. Stem bark is hard, single quilled after drying, outer dark reddish brown in colour with presence of lenticels, longitudinal cut fibres, rough in surface. Diagrammatic section, of the bark, shows outer several layered cork followed by cortical region along with medullary rays. Powder tortilla(brown) in colour; odour slightly aromatic; taste astringent; texture fibrous. Loss on drying at 110°C was found to be 7.41% and 8.60% of stem and stem bark respectively. HPTLC results shows 3 peaks and 0 peak at 254 and 366 nm of stem and 3 peaks at 254 and 366 nm of stem bark respectively. Discussion and Conclusion: Woody stem and presence of brown content, tannin, rhomboidal and prismatic crystals in stem and stem bark are the diagnostic characters.

The frontal longitudinal system as revealed through the fiber microdissection technique: structural evidence underpinning the direct connectivity of the prefrontal-premotor circuitry.

The purpose of this study was to investigate the morphology, connectivity, and correlative anatomy of the longitudinal group of fibers residing in the frontal area, which resemble the anterior extension of the superior longitudinal fasciculus (SLF) and were previously described as the frontal longitudinal system (FLS). Fifteen normal adult formalin-fixed cerebral hemispheres collected from cadavers were studied using the Klingler microdissection technique. Lateral to medial dissections were performed in a stepwise fashion starting from the frontal area and extending to the temporoparietal regions. The FLS was consistently identified as a fiber pathway residing just under the superficial U-fibers of the middle frontal gyrus or middle frontal sulcus (when present) and extending as far as the frontal pole. The authors were able to record two different configurations: one consisting of two distinct, parallel, longitudinal fiber chains (13% of cases), and the other consisting of a single stem of fibers (87% of cases). The fiber chains' cortical terminations in the frontal and prefrontal area were also traced. More specifically, the FLS was always recorded to terminate in Brodmann areas 6, 46, 45, and 10 (premotor cortex, dorsolateral prefrontal cortex, pars triangularis, and frontal pole, respectively), whereas terminations in Brodmann areas 4 (primary motor cortex), 47 (pars orbitalis), and 9 were also encountered in some specimens. In relation to the SLF system, the FLS represented its anterior continuation in the majority of the hemispheres, whereas in a few cases it was recorded as a completely distinct tract. Interestingly, the FLS comprised shorter fibers that were recorded to interconnect exclusively frontal areas, thus exhibiting different fiber architecture when compared to the long fibers forming the SLF. The current study provides consistent, focused, and robust evidence on the morphology, architecture, and correlative anatomy of the FLS. This fiber system participates in the axonal connectivity of the prefrontal-premotor cortices and allegedly subserves cognitive-motor functions. Based in the SLF hypersegmentation concept that has been advocated by previous authors, the FLS should be approached as a distinct frontal segment within the superior longitudinal system.