End Portion Research Articles

Experimental and Theoretical Studies on Plastic Torsional Buckling of Steel Buckling-Restrained Braces

A type of partly-welded BRB was proposed in this paper to mitigate the unfavourable effect of the welds on the low-cycle fatigue property of BRBs. Three partly-welded BRB specimens under different strain amplitudes were tested and the plastic torsional buckling of the end portion was observed in two specimens. According to the experimental results, the strain amplitude is an important factor for the torsional buckling of the end portion. The critical stress declines with the increase of the strain amplitude, while the maximum compressive stress increases with the growth of the strain amplitude. Even though the hysteretic behaviour of specimens under large strain amplitudes met the requirement by seismic provisions (AISC 2010), torsional buckling is an undesired failure mode for BRBs, which leads to great torsional deformation of BRBs. Based on the principle of minimum potential energy, a theoretical formula of the critical stress was provided in this paper, which gave a good prediction to the failure mode. Moreover, a recommendation value of the calculated length based on the theoretical equation was given for the design to avoid torsional buckling in the unrestrained part of the BRB's yielding segment.

Numerical investigations of the mechanical properties of a braided non-vascular stent design using finite element method

This paper discusses various issues relating to the mechanical properties of a braided non-vascular stent made of a Ni–Ti alloy. The design of the stent is a major factor which determines its reliability after implantation into a stenosed non-vascular cavity. This paper presents the effect of the main structural parameters on the mechanical properties of braided stents. A parametric analysis of a commercial stent model is developed using the commercial finite element code ANSYS. As a consequence of the analytical results that the pitch of wire has a greater effect than other structural parameters, a new design of a variable pitch stent is presented to improve mechanical properties of these braided stents. The effect of structural parameters on mechanical properties is compared for both stent models: constant and variable pitches. When the pitches of the left and right quarters of the stent are 50% larger and 100% larger than that of the central portion, respectively, the radial stiffness in the central portion increases by 10% and 38.8%, while the radial stiffness at the end portions decreases by 128% and 164.7%, the axial elongation by 25.6% and 56.6% and the bending deflection by 3.96% and 10.15%. It has been demonstrated by finite element analysis that the variable pitch stent can better meet the clinical requirements.

Novel curved balloon catheter for dilating postoperative angled lesions associated with congenital heart disease.

This study aimed to analyze the surface stress generated by a novel curved balloon and assess its efficacy for treating angular lesions associated with congenital heart disease. Obstructions at the anastomosis of aortopulmonary shunts and cavopulmonary connections may occur postoperatively. Catheter interventions are often performed for such lesions; however, acute angulation may cause balloon slippage or inappropriate stress on the vessel wall. We dilated the curved balloon in a curved vessel model and measured the resultant wall stress and its distribution. Clinical evaluations were performed using this balloon in angled lesions. In the curved vessel model, curved balloons generated uniform stress on the lesser and greater curvatures (curved type, lesser/greater = 0.343 MPa/0.327 MPa; P = 0.61), whereas straight balloons caused disproportionate stress (straight type, lesser/greater = 0.358 MPa/0.254 MPa; P = 0.19). However, the difference in average stress was not statistically significant. Furthermore, the stress was uniform along the entire length of the curved balloon, but differed between the mid and end portions of the straight balloon. Curved balloon dilations were performed for 10 lesions in 7 patients. The curved balloon conformed well to the angulated lesion without slipping. The median percent change in the minimal lumen diameter (MLD) was 64% (range, 0-206%). In 5 lesions, MLD increased by ≥50%. Oxygen saturation increased by 5% (0-9%). Although further clinical evaluation is necessary, this novel curved balloon may be a reasonable alternative in angled lesions, providing better conformability and preventing excessive stress to the vessel wall adjacent to the stenosis.

Replantation of hand multi-level severances with 17 segments

Traumatic injuries of the hand and fingers might be devastating with irretrievable functional and psychological consequences in injured individuals. We present a case of successful replantation of hand multi-level severances with 17 segments to address the best way of treatment of such injury.The patient was 18-year-old female with multi-level severances due to cutting injury. During the surgery, we adopted unifying coordination and grouping surgery. Moreover, we tried to improve the quality of vascular anastomosis with various measures and shorten operative time. Postoperatively, we closely observed the patient to effectively prevent and treat vascular crises. Furthermore, we acquired utmost hand function recovery through enhancing functional rehabilitation exercise. The case was followed-up regularly. As a result, the replanting palm and all fingers survived successfully. Abdominal pedicle flaps were used to repair the skin of the distal end portion of thumb and middle finger due to severe injury. At 5-year follow-up, the prehension function of the hand was restored and the patient was capable of general labour and normal activity with the replanted hand.This report demonstrated our experience of successful treatment of a rare and severe case of hand injury. Accordingly, we recommend grouping surgery, closely coordination, effective and comprehensive intra-operative and post-operative technical operations and treatments. Postoperative functional rehabilitation exercise can restore utmost hand function.

Visual Technique for Detecting Weld Position Based on Neural Network Technology

Seam tracking technology is an important area of research automatic arc welding, precise seam tracking is crucial to achieve high quality welds. In order to achieve precise seam tracking, seam deviation (the weld center arc deviation) detection is a key. Unlike the conventional method by image processing techniques to obtain the seam deviation information directly, but selected image processing area (including the distal end portion of the molten pool welds and the front end of the pool), and analyzed as a pool image centroid characteristic parameters of the weld deviation. Study these parameters to create a new method for visual weld deviation measurement model, establish the weld center neural network model using artificial neural network modeling technology.

Study on Regression Model of Measuring Weld Position

Seam tracking technology is an important area of research automatic arc welding, precise seam tracking is crucial to achieve high quality welds. In order to achieve precise seam tracking, seam deviation ( the weld center arc deviation) detection is a key. Unlike the conventional method by image processing techniques to obtain the seam deviation information directly, but selected image processing area (including the distal end portion of the molten pool welds and the front end of the pool), and analyzed as a pool image centroid characteristic parameters of the weld deviation. Study these parameters to create a new method for visual weld deviation measurement model, establish the linear regression model between pool image centroid deviation and the weld based on regression analysis theory.

Fuzzy and AHP approaches for designing a hospital bed: a case study in Bangladesh

Ergonomics in his recent revolution phase has emerged on diversified areas which pushed the authors to consider the major anthropometric considerations for designing a hospital bed for sensitive patients. In this paper, the authors tried to show some relationships among physical demands with anthropometric factors for normal hospital bed design in Bangladesh, where the concepts are relatively new and obvious. In this study, 35 patients and 35 doctors have given their opinion through a set of questionnaires. A total of 103 students from a public university in Bangladesh were targeted as the sample area for measuring anthropometric measurements. For prioritising among different design parameters, analytic hierarchy process and fuzzy logic techniques were used. Finally, at the end portion of this research work a linear regression analysis has been carried out to show the relationship of stature height with other anthropometric measurements related to normal hospital bed design.

12 ways to take a temperature

12 ways to take a temperature

Analysis of relationship between head motion events and speech in dialogue conversations

Head motion naturally occurs in synchrony with speech and may convey paralinguistic information (such as intentions, attitudes and emotions) in dialogue communication. With the aim of verifying the relationship between head motion events and speech utterances, analyses were conducted on motion-captured data of multiple speakers during spontaneous dialogue conversations. The relationship between head motion events and dialogue acts was firstly analyzed. Among the head motion types, nods occurred with most frequency during speech utterances, not only for expressing dialogue acts of agreement or affirmation, but also appearing at the end of phrases with strong boundaries (including both turn-keeping and giving dialogue act functions). Head shakes usually appeared for expressing negation, while head tilts appeared mostly in interjections expressing denial, and in phrases with weak boundaries, where the speaker is thinking or did not finish uttering. The synchronization of head motion events and speech was also analyzed with focus on the timing of nods relative to the last syllable of a phrase. Results showed that nods were highly synchronized with the center portion of backchannels, while it was more synchronized with the end portion of the last syllable in phrases with strong boundaries. Speaker variability analyses indicated that the inter-personal relationship with the interlocutor is one factor influencing the frequency of head motion events. It was found that the frequency of nods was lower for dialogue partners with close relationship (such as family members), where speakers do not have to express careful attitudes. On the other hand, the frequency of nods (especially of multiple nods) clearly increased when the inter-personal relationship between the dialogue partners was distant.

Echolocating bats emit terminal phase buzz calls while drinking on the wing

Echolocating bats are known to produce terminal buzz calls during pursuit and capture of airborne prey, however the use of buzz calls while drinking on the wing has not been previously investigated. In this study I recorded the first empirical evidence that bats produce terminal phase buzz calls while drinking on the wing. Every drinking pass recorded during this study was characterised by a terminal buzz which bats emitted immediately prior to touching the water surface with their mouth. The characteristic frequency (the frequency at the end or flattest portion of the pulse) of echolocation call sequences containing drinking buzzes varied from 25kHz to 50kHz, suggesting multiple bat species present at the study site emit buzzes while drinking on the wing. As feeding buzz calls appear to be ubiquitous among echolocating bat taxa, the prevalence of drinking buzzes clearly warrants further investigation. Drinking buzzes could potentially be used to document rates of drinking by bats in the same way that feeding buzzes are used to infer foraging activity.

Occurrence of gustducin-immunoreactive cells in von Ebner’s glands of guinea pigs

An immunohistochemical examination of guinea-pig taste buds in vallate papillae revealed gustducin-immunoreactive cells in the area of von Ebner’s glands, minor salivary glands. Since there have been no reports describing those cells in these locations for other species, we investigated these glands in order both to localize the cells and compare their immunoreactive characteristics with corresponding cells in the vallate taste buds. The gustducin-immunoreactive cells coincided with cells containing no secretory granules in the end portion of the glands, which was supported by the electron-microscopic immunocytochemistry. Double immunofluorescence microscopy confirmed these cells to be entirely immunopositive to type III inositol 1,4,5-triphosphate receptor (IP3R-3), phospholipase Cβ2 (PLCβ2), and villin and also partly immunopositive to neuron-specific enolase (NSE) and calbindin D-28K. The gustducin-immunoreactive cells in the vallate taste buds exhibited completely the same immunoreactivities for these five molecules. Accordingly, the present results give credence to a consideration that the gustducin-immunnoreactive cells in both locations are identical in function(s) e.g., chemo-reception.

Sagittal and coronal plane location of the popliteal artery in the open-wedge high tibial osteotomy

The objectives of this study were (1) to evaluate the sagittal and coronal plane location of the popliteal artery during the advancement of open-wedge high tibial osteotomy and (2) to confirm the effect of osteoarthritis if it changes the relationship between the popliteal artery and posterior cortex. Two hundred consecutive patients were enrolled, and we divided patients into two subgroups according to age and cartilage status in the radiologic report of magnetic resonance imaging (group I: 100 non-arthritic knees; group II: 100 arthritic knees). For prediction of the location of the popliteal artery during the operation, sagittal and coronal plane location along the osteotomy plane was evaluated. The distance between the posterior cortex of the osteotomy and popliteal artery was 13-14 mm on the sagittal plane, and the popliteal artery was located at an approximately 35 ± 5.5 mm portion from the starting point of the osteotomy on the coronal plane. The distance at the starting point of osteotomy was larger than at the end portion and prominent area. In comparison between groups I and II, group II showed a larger distance on the sagittal planes [osteotomy-vascular: 13.6 vs 14.4 (p = 0.01), fibula-vascular: 4.88 vs 6.5 (p < 0.01), and prominence-vascular: 4.3 vs 5.3 (p < 0.01)] compared to the group I. Special caution and some protection should be given until the approximately 35 mm portion from the starting point of the posteromedial cortex with consideration for the approximity on the sagittal plane. In comparison between the non-arthritic and arthritic knee, differences were observed on the sagittal plane. However, the value was minimal, and the clinical relevance was questionable. Case series, Level IV.

Ultrastructure of spermatozoa of the Atlantic cod Gadus morhua L. observed by scanning and transmission electron microscopy

The present study on wild caught Atlantic cod Gadus morhua provides a detailed description of the spermatozoa ultrastructure. The spermatozoa of G. morhua are composed of a head (nucleus) with no acrosome, a midpiece and a single flagellum. The total length is 67.69±6.33μm with a lanceolate sperm head that is 2.34±0.26μm long and 1.32±0.26μm wide. The nucleus presents homogeneous condensation of chromatin with few lacunae of decondensed chromatin. The nuclear fossa penetrates over three third of the nuclear axis and is tubiform. The axoneme is composed of a typical 9+2 microtubular doublet structure and is enclosed by the plasma membrane. Central microtubules are absent from the proximal portion of the anterior end of nuclear notch and a distal centriole complex is perpendicular to the axoneme. A group of mitochondria and vesicles is present in the midpiece. The ultrastructure of the Gadidae G. morhua spermatozoon differs from the structures described earlier for other Gadiformes. The unique features may be synapomorphic for marine Gadidae, and may contribute to the study of phylogenetic relationships in teleost fishes, and be a reference for future studies on spermatozoon quality and morphology in fish.

Aspectos Ultrassonográficos Do Tumor De Kuttner E Seu Diferencial Nas Patologias Cervicais

To describe the clinical and radiological aspects of Kuttner's tumor, emphasizing the discussion of the differential diagnosis of cervical pathologies. RM, 29 years old, male, complaining of pain and increase in volume of the left submandibular region 1 month ago, with reports of previous similar episodes. For diagnostic cervical ultrasonography was performed which revealed left submandibular gland with increased dimensions, lobulated, diffusely heterogeneous echotexture associated with images consistent with calculations in the region proximal to the duct of Wharton. A biopsy revealed lymphocytic infiltration periductal glandular, ductal ectasia and irregular sclerosis. Chronic sclerosing Sialoadenitis (Kuttner tumor). Chronic sclerosing sialadenitis, also called Kuttner tumor, is a unusual salivary gland chronic inflammatory fibrosing. It mainly affects the submandibular, with the highest incidence between 30 and 70 years, regardless of sex, predominantly unilateral. Clinically increase and hardening of the gland with or without pain, recurrent. This sialolithiasis ductal associated with the end portion by 30 to 85% of cases. The main differential diagnoses are Kimura disease, lymphoma, sarcoidosis and Sjogren's Syndrome. Definitive diagnosis is by histopathology. The prognosis is favorable and there are no reports of malignant transformation.

Morphological and molecular identification of Tetratrichomonas flagellates from the giant anteater (Myrmecophaga tridactyla)

A tetratrichomonad flagellate found in the diarrhoeic faeces of a 5years-old male giant anteater (Myrmecophaga tridactyla) was characterised by morphological and genetic analysis. This protozoan presents four anterior flagella of unequal length and a recurrent flagellum attached to the undulating membrane without a free end portion, and a broad axostyle projection. Numerous vacuoles of different sizes containing bacteria and digestion products were found. The complete sequence of the DNA coding for the 16S rRNA-ITS1-5.8S rRNA-ITS2 region was also obtained in order to compare this isolate with other tetratrichomonad species. The sequence obtained was identical to others previously obtained by other researchers from bovines and turtles (Geochelone sp.). It is not easily explainable how the same organism could be found in such different hosts and locations; however these results indicate that some tetratrichomonad species could have a wide host range and could survive in a wide range of environmental conditions.

Effects of Verticillium dahliae Infection on Stem‐End Chip Defect Development in Potatoes

ABSTRACTPotato chips are the most popular snack food in the United States with annual retail sales of over US$6 billion. Stem‐end chip defect, which is characterized by dark color of the vasculature and surrounding tissues at the tuber stem end portion of fried chips, is an important tuber quality concern for U.S. chip production. The cause of stem‐end chip defect is not known. Verticillium wilt, caused by a vascular fungal pathogen Verticillium dahliae Kleb., is a persistent disease of potato (Solanum tuberosum L.) and other vegetables that causes early plant senescence and yield reductions. A 2‐yr field trial was conducted to investigate the effects of V. dahliae on stem‐end chip defect development and the activity of acid invertase at the apical (bud) and basal (stem) ends of tubers. Our results show that potato plants that were more infected with V. dahliae had a higher incidence of severe stem‐end chip defects than plants with less V. dahliae infection. Verticillium dahliae infection of plants was correlated with an upregulation of acid invertase activity and an accumulation of reducing sugars on the stem end of tubers. Reducing sugars give rise to dark‐colored defects as a result of pigments produced by the Maillard reaction during frying.

ISUOG Practice Guidelines: use of Doppler ultrasonography in obstetrics

<scp>ISUOG</scp> Practice Guidelines: use of Doppler ultrasonography in obstetrics

Stress Analysis of FRP Composite Cylinder with Closed Ends

Composite cylinders made of a polymer matrix such as epoxy reinforced with glass or carbon fibers possess extremely high strength. Proper modeling of FRP composite cylinder is very essential for many applications. FRP composite cylinders are commonly used in the aerospace, automotive, marine and construction industries. The present work is to study the variation of stressesat the top end, middle and bottom end portions of a composite cylinder by varying the diameter to thickness ratio(S) and fiber angle (θ).The four layered angle ply (θ/-θ/-θ/θ) composite cylinder is considered forthe present work and behavior of each portion (Top end, middle and Bottom end) is studied.For the present work composite cylinder is modeled in ANSYS and analysis was carried out using numerical software. It isfound thatthe increment of stress takes place linearly with respect to D/t ratio due to reduction in thickness of the layer.The critical fiber angle is 450 to 600 as it offers high resistance against axial and circumferential deformation in middle and end portions.

INTRAVASCULAR ULTRASOUND TECHNIQUES

Intravascular ultrasound techniques provide for intravascular imaging using contrast agents and nonlinear techniques. An ultrasound imaging device for detecting internal properties of a target body comprises an ultrasound transducer positioned at a distal end portion of a catheter, for transmitting excitation pulses and for receiving echo signals. A signal processor analyses echo signals at harmonics and/or subharmonics of the transmit frequency. The catheter may include a contrast agent delivery conduit extending along the catheter, the delivery conduit having an exit orifice proximal to the ultrasound transducer. The device may discriminate between echo signals respectively arising from interaction with tissue and from the interaction with contrast agent. The device may generate an image of the site of interest using non-linear components of the received ultrasound echo signals.

Assembly Bonded at the Ends: Could Thinner and Longer Legs Result in a Lower Thermal Stress in a Thermoelectric Module Design?

An analytical (mathematical) thermal stress model has been developed for an electronic assembly comprised of identical components bonded at their end portions and subjected to different temperatures. The model is used to assess the effect of the size (dimension in the x-direction) and compliance of the bonded regions (legs) on the maximum interfacial shearing stress that is supposedly responsible for the mechanical robustness of the assembly. The numerical example is carried out for a simplified two-legged Bismuth-Telluride-Alloy (BTA)-based thermoelectric module (TEM) design. It has been determined that thinner (dimension in the horizontal, x-direction) and longer (dimension in the vertical, y-direction) bonds (legs) could result in a considerable relief in the interfacial stress. In the numerical example carried out for a 10 mm long (dimension in the x-direction) TEM assembly with two peripheral 1 mm thick (dimension in the x-direction) legs, the predicted maximum interfacial shearing stress is only about 40% of the maximum stress in the corresponding homogeneously bonded assembly, when the bond occupies the entire interface between the assembly components. It has been determined also that if thick-and-short legs are employed, the maximum interfacial shearing stress might not be very much different from the stress in a homogeneously bonded assembly, so that there is no need, as far as physical design and robustness of the assembly is concerned, to use a homogeneous bond or a multileg system. The application of such a system might be needed, however, for the satisfactory functional (thermo-electrical) performance of the device. In any event, it is imperative that sufficient bonding strength is assured in the assembly. If very thin legs are considered for lower stresses, the minimum acceptable size (real estate) of the interfaces (in the horizontal plane) should be experimentally determined (say, by shear-off testing) so that this strength is not compromised. On the other hand, owing to a lower stress level in an assembly with thin-and-long legs, assurance of its interfacial strength is less of a challenge than for an assembly with a homogeneous bond or with stiff thick-and-short legs. The obtained results could be used particularly for considering, based on the suggested predictive model, an alternative to the existing TEM designs, which are characterized by multiple big (thick-and-long) legs. In our novel design, fewer small (thin-and-short) legs could be employed, so that the size and thickness of the TEM is reduced for the acceptable stress level.