Small Protrusion Research Articles

Meningocele and Meningoencephalocele in Piglets: Pathologic and Imaging Aspects

Background: Meningocele and meningoencephalocele are rare congenital deformities characterized by herniation of the meninges and of the meninges and brain tissue through a bone defect in the skull (cranioschisis), respectively. Descriptions of these malformations in pigs are scarce in the international literature and non-existent in Brazil, with only one case of cranioschisis with brain exposure (without protrusion of the meninges and covered by skin) reported to date. Here, we report a case of meningocele and another of meningoencephalocele in piglets in the state of Bahia and describe the main related anatomopathological and imaging characteristics (radiographic and ultrasonographic).Case: The congenital malformations occurred in newborn piglets from a farm located in the city of Catu, Bahia, Brazil, which presented with an evident large saccular area positioned dorsally to the head. The animals died 48 h after birth and were referred to the Laboratory of Animal Pathology of the Federal University of Bahia, for the studies and diagnostic conclusion. Postmortem ultrasound examinations showed that the region was filled with fluid and associated with a small brain protrusion in case 1 and a defect in the skull bone, which had its orifice dimensions estimated. Despite the superimposition of structures, the skull malformation was identified on radiographic examination (case 1) and measured on ultrasonographic examination (cases 1 and 2). During necropsy, the piglets presented with a marked marked bulge of saccular appearance under the skin in the frontal region. The saccular formation was floating, internally covered by dura mater and filled with reddish serous liquid (liquor).Discussion: The diagnoses of meningoencephalocele and meningocele in newborn piglets were established based on morphological changes identified on ultrasound and necropsy. Although the ultrasound diagnosis of meningocele and meningoencephalocele are routinely made in human medicine, they are still limited in veterinary medicine in cases of malformations in production animals, with no case report in pigs. A Brazilian textbook on pig diseases cites these diseases among the main malformations that affect this species, although data on epidemiology and anatomopathological and imaging findings are not described, which highlights the importance of this study. As for the etiology of these malformations, the occurrence of two cases in piglets from the same farm in the present report may suggest the presence of genetic factors. The confirmation that inbreeding is common at farms where the cases occurred, and absence of herd renewal since 2014 (continuous use of the same breeders), reinforced this hypothesis, since inbreeding results in serious reproductive and productive disorders due to increased homozygosis and, consequently, due to the frequency of genotypes with recessive genes that cause various malformations in animals. This fact reinforces the need to make producers aware of the importance of avoiding inbreeding and the use of breeders that have generated malformed piglets to reduce the frequency of malformations. Additional studies on congenital malformations in pigs in Brazil are necessary because of the scarcity of existing data, particularly regarding the etiology and anatomopathological and imaging characteristics of these diseases.

Akut Total LMCA Tıkanıklığı ve Başarılı TAP Stentleme: STEMI'da Hangi Stratejiyi İzlemeliyiz?

The incidence of acute total left main coronary artery (LMCA) occlusion cannot be fully determined precisely, given that most of patients die unfortunately before hospital arrival. This patient group is rarely encountered but mortality is very high due to endangered a large area of myocardium and increases the risk of cardiogenic shock and lethal arrhythmia quickly. We report a case of a 40-year-old woman presented with acute anterolateral myocardial infarction and was managed successful with percutaneous intervention with TAP (T-stenting And small Protrusion) technique stenting. According to current guidelines in LMCA disease, coronary artery bypass graft (CABG) is preferred, but percutaneous coronary intervention (PCI) is life-saving treatment strategy in emergencies for hemodynamic instability patient. On the other hand, there is no specific recommendations given concerning treatment for STEMI due to LMCA and optimal revascularitazion strategy is still uncertain because of absence of a randomized trial. Alternative treatments are; primary angioplasty-stenting, emergency CABG, primary angioplasty followed by emergency CABG.

Numerical investigation of the unsteady aerodynamics of NACA 0012 with suction surface protrusion

Purpose The purpose of this paper is to investigate the effect of surface protrusions on the flow unsteadiness of NACA 0012 at a Reynolds number of 100,000. Design/methodology/approach Effect of protrusions is investigated through numerical simulation of two-dimensional Navier–Stokes equations using a finite volume solver. Turbulent stresses are resolved through the transition Shear stress transport (four-equation) turbulence model. Findings The small protrusion located at 0.05c and 0.1c significantly improve the lift coefficient by up to 36% in the post-stall regime. It also alleviates the leading edge stall. The larger protrusions increase the drag significantly along with significant degradation of lift characteristics in the pre-stall regime as well. The smaller protrusions also increase the frequency of the vortex shedding. Originality/value The effect of macroscopic protrusions or deposits in rarely investigated. The delay in stall shown by smaller protrusions can be beneficial to micro aerial vehicles. The smaller protrusions increase the frequency of the vortex shedding, and hence, can be used as a tool to enhance energy production for energy harvesters based on vortex-induced vibrations and oscillating wing philosophy.

SATB1 establishes ameloblast cell polarity and regulates directional amelogenin secretion for enamel formation

BackgroundPolarity is necessary for epithelial cells to perform distinct functions at their apical and basal surfaces. Oral epithelial cell-derived ameloblasts at secretory stage (SABs) synthesize large amounts of enamel matrix proteins (EMPs), largely amelogenins. EMPs are unidirectionally secreted into the enamel space through their apical cytoplasmic protrusions, or Tomes’ processes (TPs), to guide the enamel formation. Little is known about the transcriptional regulation underlying the establishment of cell polarity and unidirectional secretion of SABs.ResultsThe higher-order chromatin architecture of eukaryotic genome plays important roles in cell- and stage-specific transcriptional programming. A genome organizer, special AT-rich sequence-binding protein 1 (SATB1), was discovered to be significantly upregulated in ameloblasts compared to oral epithelial cells using a whole-transcript microarray analysis. The Satb1−/− mice possessed deformed ameloblasts and a thin layer of hypomineralized and non-prismatic enamel. Remarkably, Satb1−/− ameloblasts at the secretory stage lost many morphological characteristics found at the apical surface of wild-type (wt) SABs, including the loss of Tomes’ processes, defective inter-ameloblastic adhesion, and filamentous actin architecture. As expected, the secretory function of Satb1−/− SABs was compromised as amelogenins were largely retained in cells. We found the expression of epidermal growth factor receptor pathway substrate 8 (Eps8), a known regulator for actin filament assembly and small intestinal epithelial cytoplasmic protrusion formation, to be SATB1 dependent. In contrast to wt SABs, EPS8 could not be detected at the apical surface of Satb1−/− SABs. Eps8 expression was greatly reduced in small intestinal epithelial cells in Satb1−/− mice as well, displaying defective intestinal microvilli.ConclusionsOur data show that SATB1 is essential for establishing secretory ameloblast cell polarity and for EMP secretion. In line with the deformed apical architecture, amelogenin transport to the apical secretory front and secretion into enamel space were impeded in Satb1−/− SABs resulting in a massive cytoplasmic accumulation of amelogenins and a thin layer of hypomineralized enamel. Our studies strongly suggest that SATB1-dependent Eps8 expression plays a critical role in cytoplasmic protrusion formation in both SABs and in small intestines. This study demonstrates the role of SATB1 in the regulation of amelogenesis and the potential application of SATB1 in ameloblast/enamel regeneration.

Ventral Abdominal Wall Defects.

1. Sara A. Mansfield, MD, MS* 2. Tim Jancelewicz, MD, MA, MS* 1. *Division of Pediatric Surgery, Le Bonheur Children’s Hospital, University of Tennessee Health Science Center, Memphis, TN Clinicians should be aware of the strategies for prenatal and postnatal management of infants with omphalocele and gastroschisis. After completing this article, readers should be able to: 1. Recognize the implications and differences in management between gastroschisis and omphalocele. 2. Review the initial stabilization and management of infants with omphalocele and gastroschisis. 3. Review the surgical management options and rationale for infants with ventral abdominal wall defects. Abdominal wall defects represent a wide spectrum of congenital anomalies. These can range from lethal limb-body wall syndrome to benign umbilical cord hernias. Gastroschisis and omphalocele are the 2 most common defects and are the focus of this review. Although both of these diseases affect the umbilical area, they differ widely in their underlying pathogenesis, genetics, and associated disorders. Consequently, their management techniques and outcomes are quite different. This article reviews the pathogenesis, genetics, diagnostics, and outcomes for each disease, followed by an in-depth review of recent management updates. ### Pathogenesis Omphalocele (or exomphalos) is a herniation of the abdominal viscera through a midline abdominal wall defect (Fig 1). This defect is located at the base of the umbilical stalk, and herniated viscera are covered by a 3-layer membrane of peritoneum, Wharton jelly, and amnion. This contrasts with umbilical cord hernias, which are covered by intact skin and contain only a small protrusion of abdominal contents, and gastroschisis, which has no covering at all and occurs to the right of midline (Table). Omphaloceles are present in approximately 1 per 1,100 pregnancies. However, there is a high rate of spontaneous abortion, making the incidence of omphalocele per live birth approximately 1 per 4,000 to 1 per 6,000. (1) …

P5752Which is the best stenting technique for coronary bifurcation lesions? Evidence from a network meta-analysis of randomized clinical trials

Abstract Background Bifurcation lesions represent 20% of all coronary lesions treated by percutaneous coronary interventions (PCI). Although provisional technique with 1 stent in the main branch and balloon angioplasty of the side branch is considered the standard approach, the implantation of 2 stents is often being pursued with a wide variety of bifurcation stenting techniques. We thus conducted a systematic review and network meta-analysis of randomized clinical trials (RCTs) to compare clinical cardiovascular outcomes involving stenting techniques in coronary bifurcation lesions. Methods We searched on Pubmed, Google Scholar, Embase and Cochrane Library, up to October 2018 for published and unpublished RCTs that compared clinical cardiovascular outcomes in patients with bifurcation lesions treated with 7different techniques (crush [Cr]; culotte [Cu]; double kissing crush [DKCr], mini-crush [mCr], routine T-stenting [RTS], T-stenting and small protrusion [TAP], and provisional (1 stent technique)). We performed a frequentist fixed-effect network meta-analysis to estimate relative risks (RR) of major adverse cardiovascular events (“MACE”, typically defined as death, myocardial infarction and target vessel revascularization), target vessel revascularization (TVR), target lesion revascularization (TLR), and stent thrombosis (ST). Results We identified 14 studies, yielding data on 4285 patients. DKCr and mCr yielded significant reductions in MACE, TVR, and TLR when compared with the 1-stent technique (RR 0.31–0.55 [all P<0.01] and RR 0.42–0.45 [all P<0.02], respectively) and with the rest of the bifurcation techniques (RR 0.44–0.55 [all P<0.05] for DKCr and RR 0.37–0.45 [all P<0.05] for mCr). On the other hand, Cu and Cr were associated with an increased risk for ST compared to 1-stent technique (RR 3.25–4.27 [both P<0.05]) and to DKCr (RR 3.02–3.99 [both P<0.05]). We found no heterogeneity nor inconsistency between studies. Conclusions The various PCI bifurcation stenting techniques are associated with different cardiovascular outcomes, with double kissing crush and mini crush being more effective than others, including the 1-stent approach, whereas culotte and crush are associated with increased risk of stent thrombosis. Acknowledgement/Funding None

The Impact of Coarse‐Grain Protrusion on Near‐Bed Hydrodynamics

In steep rivers, sediment is often transported over immobile cobbles and boulders. Previous studies of such conditions have observed that the entrainment rate of the mobile sediment strongly depends on the level of protrusion of the immobile grains. Here experiments are conducted in a laboratory flume in order to quantify how different levels of protrusion of large aggregates above a fixed fine‐sediment bed, modeled as a patch of hemispheres, modify the local hydrodynamics near the fine‐sediment bed. Five protrusion levels defined by P=k/R= {0%, 20%, 40%, 60%, 80%} were investigated, where k is the protrusion height and R the radius. For small protrusion (P=20%), enhanced shear stress and turbulence intensity on the fine‐sediment bed is observed as the mixing layer generated at the hemisphere top impacts the fine‐sediment bed. Moreover, sweep events generated near the top of the hemispheres reach the fine‐sediment bed. For large protrusions (P ≥ 60%), the mixing layer generated near the top of the hemispheres does not reach the fine grains with the consequence that the shear stress drops. The remaining turbulence near the fine‐sediment bed, although enhanced by the wakes generated by the hemispherical caps, is quasi‐isotropic. The transition between these two distinct near‐bed flow regimes is found to be around P=40%, corresponding to the protrusion levels observed by Grams and Wilcock, https://doi.org/10.1002/2013JF002925) above which the erosion of fine sediment ceases.

Apicoporus haificum (Gymnodiniaceae), a new dinoflagellate species from sandy sediments of the Mediterranean Sea (Israel coast)

A new dinoflagellate species (Dinophyceae, Gymnodiniales)—Apicoporus haificum Krachmalny sp. nov. was described on a basis of thorough light microscopy studies. The species was found in sandy sediments (water-filled spaces between sand grains) on the eastern coast of the Mediterranean Sea (HaCarmel beach, Haifa, Israel). Apicoporus haificum possesses the following features: cells elongated (with length exceeding width by 3.1–3.8 times), lanceolate in dorsoventral projection, roundish in cross-section with slight dorsoventral compression, asymmetrical, slightly curved to the right, with antapical depression. Epicone asymmetrical, somewhat umbonate, with a small hook-shaped protrusion on the apex. Cingulum displaced, descending by 1/3 cell’s length, its distal part almost parallel to the anterior portion of sulcus. Sulcus narrow, shallow, extends from the apex to the antapical depression, with apical groove. Cell surface covered with longitudinal striations that converge on the apex and on the antapical protrusion. Chloroplasts absent. Dimensions: 75.3±2.2 μm in length, 21.4±1.5 μm in width. Comparison of A. haificum to morphologically similar Apicoporus glaber and Amphidinium scissum is discussed.

Influence of Age on Perception of Best Esthetical Profile

Statement of the Problem:As an important determinant of social acceptability, facial attractiveness can be influenced by decisions of orthodontists through treatment. The perception of facial attractiveness is influenced by several factors. Purpose:The purpose of this study was to determine the difference in perception of facial attractiveness among male and female raters in different age groups through comparison of silhouettes. Materials and Method: 208 subjects (99 male, 109 female) aged between 18 to 70 years were assigned to three groups of young adults, middle-aged and senior and rated pre-designed silhouettes on a 7-level rating scale (1= the least esthetic, 7=the most esthetic). Two series of 7 silhouettes were prepared for men and women in which the mandible was protruded or retruded in 2-mm increments from the average. The evaluators were asked to grade the profiles separately for male and female. T-test and one-way ANOVA were used for the statistical analysis with α = 0.05. Results: The first and third age groups, favored female profile 2 among class II profiles. However, the second age group preferred the average profile. Male class II profiles were rated exactly as female ones among the three age groups. The average female class III silhouette was preferred in all age groups. The first and second age group preferred the average male profile in male class III silhouettes. The oldest group however, preferred profile 2. For both sexes, the least acceptable profile in each set of silhouettes was the most protruded or retruded. Conclusion:There were few differences in perception of facial attractiveness between different age groups. In all groups, even small mandibular protrusion was unacceptable and mild retrusion was considered attractive.

Numerical Investigation of the Hemodynamics Characteristics in Coronary Bifurcation Region with Different Dual Stent Implantation Techniques

The prevalence of coronary bifurcation lesions (CBL) in the percutaneous coronary intervention (PCI) was reported to be approximately 15-20 % [Steigen (2006)]. The complex surgical techniques and the high incidence of restenosis make the treatment of CBL is still one of the most challenging fields in PCI. Even the single stent technique showed prognosis in most CBL treatment, dual stenting technique is still required in some cases. Our clinical follow-ups of dual stent implantation showed that the optimized provisional T-stenting (OPT) technique in CBL treatment has a lower restenosis rate compare with the Culotte stenting technique and T-stenting and small protrusion (TAP) technique. Though the local hemodynamic characteristics have been suggested as a key factor of the restenosis post PCI, the detailed hemodynamics features of the different dual stent implantation configurations are yet to be explored. In this study, the numerical simulations were performed to investigate the flow characteristics in coronary bifurcations with different dual stenting techniques.

Dentoalveolar Evaluation of Lower Incisors by CBCT after Treatment with Herbst Appliance.

This study aimed to evaluate the effects of the Herbst appliance on the proclination and protrusion of the lower incisors, and to verify if the device causes alveolar bone loss in the anterior region of the mandible. This is a retrospective study. The sample consisted of 35 individuals. The treatment group consisted of 22 individuals (8 girls and 14 boys; initial mean age of 8.2 years) who used the Cantilever Herbst appliance for a period of 12 months. The control group consisted of 13 individuals (3 girls and 10 boys; initial mean age of 8.9 years) who received no treatment and were followed up for a period of approximately 18 months. Cone-beam computed tomography scans were performed at the beginning and at the end of the observational period. The medullary bone thickness (MT), buccal cortical bone thickness (BCT), lingual cortical bone thickness (LCT), and lower incisors proclination and protrusion were evaluated. Data were submitted to statistical analysis (ANCOVA and Student's t-test) with a significance level of 5%. There was no significant difference in MT, BCT, LCT and incisor proclination between groups. Incisor proclination increased in the treated group with no statistical significance. The treatment group showed a significant increase in the protrusion of the incisors (p = 0.02). The Herbst appliance promoted a small proclination and protrusion of the lower incisors, without relevant clinical implications. The Herbst appliance did not cause bone loss in the anterior region of the mandible during Class II treatment.

Improvement of the Gap Adjustment in Total Knee Arthroplasty Using the Posterior Condylar Pre-cut Technique.

To provide adequate gaps for knee extension and flexion during total knee arthroplasty, a femoral component placement decreases the extension gap because the posterior capsule tension increases against the protrusion of the posterior part of the femoral component. We thought that the influence of this component on the extension gap depends on the amount of posterior femoral bone resection and the thickness of the posterior femoral components. We hypothesized that less bone resection and a thinner posterior part of the femoral component might avoid these problems. To verify our hypothesis, a 4-mm posterior condylar pre-cut technique and temporary femoral components that were 8 and 4 mm thick in the distal and posterior parts, respectively, were made using the FINE Total Knee System (Teijin-Nakashima Medical Co., Okayama, Japan). After bone resection, the pre-cut trial component was set to the femur, and the bone and component setting gaps were estimated. Seventy-one patients (98 knees) were investigated. The average bone gaps were 17.2/15.0 mm (extension/flexion, after pre-cut), 18.3/16.3 mm (after soft tissue release), and 8.7/12.2 mm (after pre-cut trial setting). After pre-cut trial setting, the extension gap decreased significantly; the amount was 1.6 mm (0-4 mm) on average (p < 0.0001), whereas a change of 3 mm or more occurred in 15 knees (15.3%), which could be problematic. The degree of these changes after component setting could be reduced by using the posterior femoral condylar pre-cut technique. However, the problem of component setting on the extension gap was not completely resolved. To precisely project the intraoperative gap to the ultimate postoperative gap, a posterior small protrusion device such as a pre-cut trial with the pre-cut technique would be necessary.

Branch ostial optimization treatment and optimized provisional t-stenting with polymeric bioresorbable scaffolds: Ex-vivo morphologic and hemodynamic examination.

The optimal side-branch (SB) ostium treatment after provisional side-branch scaffolding remains a subject of debate in bioresorbable vascular scaffold (BVS) era. In this study, we evaluated a novel optimized provisional T-stenting technique (OPT) and assessed its feasibility by comparison with T and small protrusion technique (TAP).Two provisional SB scaffolding techniques (OPT, n = 5; TAP, n = 5) were performed using polymeric BVS in a bifurcated phantom. The sequential intermediate snuggling balloon dilation, also called ostial optimal technique, was added to OPT but not TAP to dilate the side-branch ostium while the final snuggling balloon dilation applied for both procedures. Microcomputed tomography (microCT) and optical coherence tomography (OCT) were performed to assess morphology, and computational fluid dynamics (CFD) was performed to assess hemodynamics in the scaffolded bifurcations. Compared with TAP in microCT analysis, OPT created shorter neo-carina length than TAP (0.34 ± 0.10 mm vs 1.02 ± 0.26 mm, P < .01), longer valgus struts length (2.49 ± 0.27 mm vs 1.78 ± 0.33 mm, P < .01) with larger MB ostial area (9.46 ± 0.04 mm vs 8.34 ± 0.09 mm, P < .01). OCT found that OPT significantly decreased the struts mal-apposition (13.20 ± 0.16% vs 1.94 ± 0.54%, P < .01). CFD revealed that OPT generated more favorable flow pattern than TAP, as indicated by less percent (4.68 ± 1.40% vs 8.88 ± 1.21%, P < .01) of low wall shear stress (<0.4 Pa) along the lateral walls.By using BVSs for bifurcation intervention, the sequential intermediate snuggling balloon dilation is feasible for optimizing ostial SB and facilitating subsequent SB scaffolding. Results show OPT is better than TAP for bifurcated morphology and hemodynamics in this ex-vivo study.

Characterization of Helicobacter pylori-Naïve Early Gastric Cancers

Aim: Helicobacter pylori-naïve gastric cancers(GCs) have not been well documented. We aimed to characterize early H. pylori-naïve GCs. Subjects and Methods: Of 666 patients with GC resected by endoscopic submucosal dissection, H. pylori-naïve patients were extracted according to the definition: no H. pylori eradication history, negative for serum H. pylori-antibody and current H. pylori-infection tests, and no gastric atrophy by pepsinogen (PG) test, endoscopy, and histology. Results: It was found that 16 GCs were H. pylori-naïve, and classified into undifferentiated and differentiated type adenocarcinoma. All 9 undifferentiated type GCs were pale, depressed, mucosal pure signet ring cell adenocarcinoma except one of them and 7 differentiated type GCs were classified into 3 fundic gland type GCs and 4 foveolar type GCs. All fundic gland type GCs positive for PG-1 were cardia small submucosal tumor (SMT)-like protrusions with dilated vessels on the surface. All 4 foveolar type GCs were composed of dysplastic clear cells resembling foveolar epithelium, negative for PG-1 but positive for mucin 6 (MUC6) and MUC5AC. Endoscopically, all were laterally spreading elevations with papillary or villous surface. Conclusions: H. pylori-naïve GCs were infrequent at 2.5%, and classified into 3 types: a small pale depression of signet ring cell adenocarcinoma, a small SMT-like protrusion of fundic gland type GC, and a large laterally spreading elevation of foveolar type GC.

Src Kinase Dependent Rapid Non-genomic Modulation of Hippocampal Spinogenesis Induced by Androgen and Estrogen.

Dendritic spine is a small membranous protrusion from a neuron's dendrite that typically receives input from an axon terminal at the synapse. Memories are stored in synapses which consist of spines and presynapses. Rapid modulations of dendritic spines induced by hippocampal sex steroids, including dihydrotestosterone (DHT), testosterone (T), and estradiol (E2), are essential for synaptic plasticity. Molecular mechanisms underlying the rapid non-genomic modulation through synaptic receptors of androgen (AR) and estrogen (ER) as well as its downstream kinase signaling, however, have not been well understood. We investigated the possible involvement of Src tyrosine kinase in rapid changes of dendritic spines in response to androgen and estrogen, including DHT, T, and E2, using hippocampal slices from adult male rats. We found that the treatments with DHT (10 nM), T (10 nM), and E2 (1 nM) increased the total density of spines by ~1.22 to 1.26-fold within 2 h using super resolution confocal imaging of Lucifer Yellow-injected CA1 pyramidal neurons. We examined also morphological changes of spines in order to clarify differences between three sex steroids. From spine head diameter analysis, DHT increased middle- and large-head spines, whereas T increased small- and middle-head spines, and E2 increased small-head spines. Upon application of Src tyrosine kinase inhibitor, the spine increases induced through DHT, T, and E2 treatments were completely blocked. These results imply that Src kinase is essentially involved in sex steroid-induced non-genomic modulation of the spine density and morphology. These results also suggest that rapid effects of exogenously applied androgen and estrogen can occur in steroid-depleted conditions, including “acute” hippocampal slices and the hippocampus of gonadectomized animals.

Chromophore-Removal-Induced Conformational Change in Photoactive Yellow Protein Determined through Spectroscopic and X-ray Solution Scattering Studies.

Photoactive yellow protein (PYP) induces negative phototaxis in Halorhodospira halophila via photoactivation triggered by light-mediated chromophore isomerization. Chromophore isomerization proceeds via a volume-conserving isomerization mechanism due to the hydrogen-bond network and steric constraints inside the protein, and causes significant conformational changes accompanied by N-terminal protrusion. However, it is unclear how the structural change of the chromophore affects the remote N-terminal domain. To understand photocycle-related structural changes, we investigated the structural aspect of chromophore removal in PYP because it possesses a disrupted hydrogen-bond network similar to that in photocycle intermediates. A comparison of the structural aspects with those observed in the photocycle would give a clue related to the structural change mechanism in the photocycle. Chromophore removal effects were assessed via UV-vis spectroscopy, circular dichroism, and X-ray solution scattering. Molecular shape reconstruction and an experiment-restrained rigid-body molecular dynamics simulation based on the scattering data were performed to determine protein shape, size, and conformational changes upon PYP bleaching. Data show that chromophore removal disrupted the holo-PYP structure, resulting in a small N-terminal protrusion, but the extent of conformational changes was markedly less than those in the photocycle. This indicates that disruption of the hydrogen-bond network alone in bleached PYP does not induce the large conformational change observed in the photocycle, which thus must result from the organized structural transition around the chromophore triggered by chromophore photoisomerization along with disruption of the hydrogen-bond network between the chromophore and the PYP core.

Analysis of Rope Vibration Contacted to a Winch with Small Protrusion on Rope Groove

There are various types of rope models to simulate vibration of rope as previous papers have been proposed. Although these models are able to simulate rope vibration excited by measured or known force, it is impossible to simulate the vibration caused by indeterminate force, which is difficult to measure, such as the force related to contact situation between rope and pulley. Additionally these models do not take into account contact between rope and pulley. In this paper, we propose a practical model which enables us to analyze the contact under winch operation. As an initial test of simulation accuracy, we measure rope vibration excited by pulley with small protrusion on rope groove, and simulate same condition to compare the results. Finally, this paper describes the mechanism of rope vibration from the protrusion.

Inlet tube spacing and protrusion inlet effects on multiple circular tubes in the laminar, transitional and turbulent flow regimes

The purpose of this study was to investigate inlet tube spacing and protrusion effects on multiple circular tubes in the laminar, transitional and turbulent flow regimes. An experimental set-up was built for this investigation and three configurations of test sections were investigated. The first was a single-tube test section for validation purposes, of which the results were compared with literature. The second was two multi-tube test sections with three tubes spaced at different pitches. The third configuration was similar to configuration two, except that the centre tube had a small protrusion. All the tubes had an inner diameter of 3.97 mm, and long tube lengths of 6 m were used to ensure fully developed flow. The tubes were electrically heated that ensured a constant heat flux heating condition. Water was used as the test fluid, and the Prandtl number varied between 3 and 7. The experiments were conducted at heat fluxes of 2, 3 and 4 kW/m2 for Reynolds numbers between 1000 and 7000, to ensure that the transitional flow regime, as well as sufficient parts of the laminar and turbulent flow regimes, were covered. The tubes were spaced apart from each other at 1.25, 1.4 and 1.5 times the outer tube diameter, and the protrusion of the centre tube was 10% of the tube inner diameter. It was found that an increased pitch ratio dampened the inlet disturbances in the centre tube and reduced the flow asymmetry in the side tubes, therefore the differences in the critical Reynolds numbers and transition gradients of the three tubes decreased. As the inlet disturbances were damped in the centre tube, transitional was delayed compared to a single tube with a square-edged inlet. For the side tubes, the increased flow asymmetry led to increased critical Reynolds numbers, as well as increased transition gradients. The presence of a protrusion inlet in the centre tube significantly increased the asymmetry of the flow in the side tubes, which led to an additional increase in the critical Reynolds numbers and the transition gradients increased. Free convection effects also led to increased critical Reynolds numbers and transition gradients, as well as decreased differences between the results of the tubes in the multi-tube set-up when a square-edged inlet was used. However, free convection effects were not able to dampen the inlet disturbances caused by a protrusion inlet in the centre tube.

Slip length for transverse shear flow over a periodic array of weakly curved menisci

By exploiting the reciprocal theorem of Stokes flow, we find an explicit expression for the first order slip length correction, for small protrusion angles, and for transverse shear over a periodic array of curved menisci. The result is the transverse flow analogue of the longitudinal flow result of Sbragaglia and Prosperetti [“A note on the effective slip properties for microchannel flows with ultrahydrophobic surfaces,” Phys. Fluids 19, 043603 (2007)]. For small protrusion angles, it also generalizes the dilute-limit result of Davis and Lauga [“Geometric transition in friction for flow over a bubble mattress,” Phys. Fluids 21, 011701 (2009)] to arbitrary no-shear fractions. While the leading order slip lengths for transverse and longitudinal flow over flat no-shear slots are well-known to differ by a factor of 2, the first order slip length corrections for weakly protruding menisci in each flow are found to be identical.

Optimisation of injection-related parameters using the non-linear programming by quadratic Lagrangian algorithm for a marine medium-speed diesel engine

The match of an injector with the combustion chamber was studied through computational fluid dynamics simulation under four different engine loads. Four design parameters including the start of injection, spray angle, injector protrusion length and swirl ratio were examined. The Latin hypercube together with a non-linear programming by quadratic Lagrangian algorithm were used in the optimisation. Comparisons were made in the engine loads in terms of the optimisation history, objectives, sub-objectives and design parameters. The commonalities of the design parameters of the optimums were summarised. Additionally, a detailed combustion process comparison was conducted on the same engine loads (100% and 25% engine loads) between the optimum and baseline designs, respectively. Finally, the effects of the design parameters on the objective were investigated by the response surface methodology. The results indicate that the non-linear programming by quadratic Lagrangian method is an effective algorithm to spot the optimums with the best trade-off between nitrogen oxides and soot emissions. The optimisation process presents better qualities at 100% and 75% engine loads than in the case of 50% and 25% engine loads. The design parameters of the optimum under each engine load have something in common, namely, that they all prefer late injection, low swirl, large injection angle and slightly smaller nozzle protrusion length. Besides, start of injection and swirl ratio have larger influence on the objective as opposed to the nozzle protrusion length and spray angle. The large start of injection together with the small swirl ratio can reduce the objective significantly and vice versa. A large nozzle protrusion length with a small spray angle contributes to the reduction of the objective and so does the combination of a small nozzle protrusion length with a large spray angle.