Short Shaft Research Articles

Treatment of coxofemoral dislocation and short oblique mid shaft tibial fracture by modified toggle pin technique with locking compression plate method in a dog

Treatment of coxofemoral dislocation and short oblique mid shaft tibial fracture by modified toggle pin technique with locking compression plate method in a dog

Nonlinear vibration characteristics of an aeroengine cantilever flexible rotor considering interference fit and unbalance

Aeroengine power turbine rotor is a typical nonlinear rotor system, in which the interference connection between long shaft and short shaft has a prominent influence on the coupling vibration of the system, especially at high speed, the nonlinear stiffness change of interference contact is more obvious. Therefore, the paper considers the change of the contact characteristics of the long shaft and the short shaft of the turbine rotor, and the nonlinear restoring force of the bearing to analyze the dynamic characteristics of the rotor. Firstly, according to the theory of elasticity, the contact parameters under different speed states are calculated, the contact stiffness model under interference fit is established, and the relationship between contact stiffness and speed is analyzed. Secondly, according to the Hertz contact theory, a bearing nonlinear restoring force model considering time-varying characteristics is established. Finally, the dynamic model of the bearing-flexible rotor coupling considering interference contact is established. The influence of contact parameters and unbalance parameters on the nonlinear vibration characteristics of the rotor is analyzed by amplitude-frequency curve, bifurcation diagram, time-domain waveform, spectrum diagram, trajectory diagram and Poincaré diagram. In addition, the simulation results are compared with the experiment results of the rotor test rig to verify the accuracy of the established dynamic model. By analyzing the influence of different parameters such as interference magnitude, unbalance position, unbalance magnitude and unbalance couple on the nonlinear vibration of the rotor, the basis for the design and vibration control of the cantilever turbine rotor is provided.

Short shaft ratio: A novel predictor for dural ossification in patients with ossification of the ligamentum flavum

BackgroundDural ossification (DO) is strongly correlated with an increased incidence of complications during the surgery for the patients with thoracic ossification of the ligamentum flavum (OLF). Some methods for predicting DO have emerged, but the accuracy remains to be improved. We aimed to find a more accurate way to predict the appearance of DO. MethodsRetrospective study was adopted in this study. According to the intraoperative findings, ninety-one patients with thoracic OLF were ultimately included and divided into two groups based on the presence or absence of DO. Patient characteristics and radiographic data were recorded. The residual area ratio (RAR, residual area/cross-section area of normal spinal canal × 100%) and the short shaft ratio (SSR, the length of short shaft of the ellipse-like shape/the length of the spinal canal × 100%) were measured and calculated by 2 independent observers, followed by statistical analysis. The receiver operating characteristic curve was used to evaluate the accuracy of the SSR and RAR in predicting DO. ResultsNo significant differences were found in sex, age and BMI between the DO group and the non-DO group. The mean RAR (and standard deviation) in the Non-DO group (62.6% ± 10.2%) was significantly higher (p < 0.001) than that in the DO group (46.1% ± 10.5%). The mean SSR (and standard deviation) in the Non-DO group (61.6% ± 6.0%) was significantly higher (p < 0.001) than that in the DO group (43.6% ± 9.2%). The receiver operating characteristic curve indicated that the SSR and RAR can be used as the efficient indicators to identify DO, and the SSR has a higher accuracy in indicating the presence of DO, with a cutoff value of ＜48.71% (sensitivity of 100% and specificity of 85.0%). ConclusionThe SSR can be used as a supplement parameter to traditional methods to predict DO, and it could be a better predictor. And, compared with bilateral and bridged type, unilateral type of OLF was more likely to develop DO with a larger SSR.

Finite Element Simulation and Structural Optimization of Structural Flow Sequential Field for Sequential Boost Switching Valve

Turbocharging technology is an important part of engine technology. Under the working condition of 730 °C and 0.5 MPa, the valve plate opening and closing will bear the high pressure of the internal fluid medium, resulting in the deformation of the switching valve. In this paper, ANSYS finite element simulation software is used to establish the valve fluid domain model, and the stress field and deformation law of the valve under the valve plate opening of 0 °~ 90 °are simulated and analyzed. Based on the fluid-solid coupling theory, the deformation and stress distribution of the valve plate structure are obtained by simulation analysis. The simulation results show that the smaller the opening of the valve plate, the more disordered the flow condition. As the opening increases, the flow tends to be stable. When the opening is 30 °, the negative pressure inside the valve is the largest; combined with the fluid-solid coupling analysis, the maximum stress load on the valve plate appears at the connection between the valve plate and the long valve shaft and the short valve shaft, and the maximum pressure appears at the opening of 60 °, which is 37.144 MPa; the maximum deformation occurs at the outer edge of the valve plate. Based on the results of this simulation analysis, the corresponding multi-objective structural optimization of the valve structure is carried out to provide technical reference for the structural design of similar valves.

Primary dynamic interlocking nail in femoral shaft fracture: A case series

Introduction and importanceFemoral shaft fracture is one of the most frequent injuries encountered by an orthopedic surgeon. Surgical treatment is commonly needed. Intramedullary nailing remains the gold-standard in surgical treatment of femoral shaft fracture. One of the constant dilemmas in intramedullary nailing is whether to use a static or dynamic locking screw for treating femoral shaft fractures. Case presentationWe reported three cases of simple femoral shaft fracture and surgically fixed with primary dynamic interlocking nail. Closed reduction with reamed nail was performed in 2 cases, and mini open reduction with un-reamed nail was performed to the other one. Early weight bearing was instructed at day 1 post-operative. Mean follow-up period was 12.6 months. A solid bony union was achieved by all patients, and no complications were observed at the final follow up. Clinical discussionIntramedullary nailing can be made static or dynamic. It is thought that in static mode of the intramedullary nailing, the axial weight is transferred through the locking screws rather than the fracture site, thus altering the callus formation and delaying fracture healing. A prompt dynamization of the fragments allows the contact of both fragments during mobilization and promotes early callus formation. ConclusionPrimary dynamic interlocking nail is an effective option for surgical treatment in simple or short oblique femoral shaft fracture.

Effect of postoperative fracture gap on bone union: A retrospective cohort analysis of simple femoral shaft fractures

BackgroundIntramedullary nailing (IMN) is considered the gold-standard treatment for femoral shaft fractures. The post operative fracture gap is commonly recognized as a risk factor for nonunion. However, no evaluation standard for measuring the fracture gap size has yet been established. In addition, the clinical implications of the fracture gap size have also not been determined so far. This study aims to clarify how we should evaluate fracture gaps when assessing simple femoral shaft fractures with radiographs and to determine the acceptable cut-off value of the fracture gap size in simple femoral shaft fractures. MethodA retrospective observational study with a consecutive cohort was conducted at the trauma center of a university hospital. We investigated the fracture gap using postoperative radiography and the postoperative bone union of transverse and short oblique femoral shaft fractures fixed by IMN. The receiver operating characteristic curve analysis was conducted to obtain the fracture gap's mean, minimum, and maximum cut-off values. Fisher's exact test was used at the cut-off value of the most accurate parameter. ResultsIn the four nonunions among the 30 cases, the analysis using ROC curves revealed that the maximum value had the highest accuracy among the maximum, minimum, and mean values of fracture-gap size. The cut-off value was determined to be 4.14 mm with high accuracy. Fisher's exact test showed that the incidence of nonunion was higher in the group with a maximum fracture gap of 4.14 mm or greater (risk ratio = not applicable, risk difference = 0.57, P = 0.001). ConclusionIn simple transverse and short oblique femoral shaft fractures fixed with IMN, the fracture gap on radiographs should be evaluated by the maximum gap in the AP and lateral views. The remaining maximum fracture gap of ≥4.14 mm would be a risk factor for nonunion.

Single Buried Intramedullary K-Wire Fixation in Nonthumb Metacarpal Shaft Fractures with Immediate Postoperative Mobilization without Any Immobilization.

This study aims to evaluate the outcomes of single intramedullary K-wire fixation in nonthumb, metacarpal shaft fractures with immediate postoperative hand mobilization without any immobilization. This is a retrospective case series conducted from January 2019 to December 2022. We included patients with closed, simple transverse, or short oblique metacarpal shaft fracture treated with single, 1.4 mm, intramedullary K-wire fixation. Gentle postoperative range of motion exercise was encouraged in every patient without any hand, finger, or wrist motion restriction material. Clinical outcomes were evaluated with total active flexion; grip strength; disability of arm, shoulder, and hand (DASH) score; and the American Society for Surgery of the Hand Total Active Flexion (ASSH TAF) score. This study included 34 patients, 25 males and 9 females with a mean age of 33.14 years (ranging 18-59). A total of 43 metacarpal shafts were treated. The mean DASH score at two and 6 weeks postoperative was 41.5 (ranging 19.16-60.34) and 9.58 (ranging 0.83-23.27). The mean final DASH score at last follow-up was 3.48 (ranging 0-8.33). Mean TAF at 2 weeks postoperative, 6 weeks postoperative, and at final follow-up was 203.8 (ranging 185-240), 238.2 (ranging 220-270), and 259.25 (ranging 240-270) degrees, respectively. The mean grip strength of the injured hand was 66.14 and 86.1% of the uninjured hand at 6 weeks and 3 months postoperative. There was no nonunion, malrotation, or infection. In conclusion, single intramedullary K-wire fixation gives excellent outcomes in the treatment of single or multiple, simple, metacarpal shaft fractures without the need of postoperative immobilization.

Effect of fracture level on the residual fracture gap during tibial intramedullary nailing for tibial shaft fractures.

The development of fracture gap during intramedullary nailing in tibial fractures is associated with poor fracture fragment contact and increased time to union and complications. This study aimed to evaluate the effect of the fracture level in the development of the fracture gap and the effect of the fracture gap on pain, radiologic and functional outcomes, and complication rate. A total of 45 patients who underwent reamed intramedullary nailing due to closed transverse or short oblique tibial shaft fractures were divided into the proximal fracture group and the distal fracture group. The correlations between the visual analog scale (VAS) score, modified radiograph union score for tibias (RUST), and postoperative 1-year lower extremity functional scale scores, residual fracture gap, and time to union were evaluated. The mean fracture gap amounts in the immediate postoperative anteroposterior and lateral radiographs were 5.6±1.7 and 6.0±1.7mm in proximal fractures and 0.3±2.4mm and 0.4±2.3mm in distal fractures, respectively (p<0.001 and p<0.001, respectively). The mean time to union was 21.9±2.9 weeks in the proximal fracture group and 16.7±2.4 weeks in the distal fracture group (p<0.000). The residual fracture gap amount significantly correlated with the level of fracture (r=0.811, p<0.001). Tibial shaft fractures proximal to the isthmus level tend to develop significantly larger fracture gaps than distal fractures. It is associated with increased time to union and radiographic union scores as well as slightly higher complication and reoperation rates.

Cranial Anatomy of the Caseid Synapsid Cotylorhynchus romeri, a Large Terrestrial Herbivore From the Lower Permian of Oklahoma, U.S.A

The detailed description of the cranial anatomy of Cotylorhynchus romeri, a very large caseid synapsid from the lower Permian Hennessey Formation of Oklahoma, uncovered several potential autapomorphies, including parietal-postorbital contact greatly reduced by broad anterior process of supratemporal; the postparietals are transversely broad and contact the supratemporals laterally; the quadratojugal has a pennant-like occipital process; the stapes has a short shaft and a ventral process that abuts against the palate; the bulbous marginal dentition narrows distally and carries three small denticles; the vomer has three large teeth along its medial edge; parasphenoidal dentition is present; and the surangular overlaps the posterodorsal tip of the dentary and excludes it from the coronoid eminence. Owing to lack of comparative cranial material in most large caseids, the evolutionary history of these autapomorphies remains ambiguous because they cannot be determined in the closest relatives of Cotylorhynchus romeri. Our description of the skull of Cotylorhynchus romeri is consonant with the hypothesis that this caseid was a high-fibre terrestrial herbivore. The recent hypothesis that Cotylorhynchus romeri was primarily aquatic was proposed on a paleobiological basis that ignored paleontological and taphonomic evidence from the Hennessey Formation. Autochthonous preservation of several articulated skeletons of Cotylorhynchus romeri in subaerially deposited sediments that also preserve “swarms” of an aestivating fossil amphibian (Brachydectes) indicate that this caseid was the largest tetrapod of a terrestrial fauna that lived in a monsoonal climate.

Urocleidoides spp. (Monogenea: Dactylogyridae) from the gills of Parodon nasus (Characiformes: Parodontidae) from a Brazilian stream with descriptions of two new species.

Urocleidoides spp. are reported from the gills of 20 specimens of Parodon nasus (standard length 8.512 cm), from the Indiana stream, Tiet River, Upper Paran River basin, municipality of Botucatu, So Paulo State, Brazil. Urocleoidoides tenuis and two new species were found. Urocleidoides indianensis n. sp. differs from its congeners mainly by the morphology of the vaginal sclerite that is robust, sickle-shaped, and forked at the distal end; and by the bulbous-shaped accessory piece of the male copulatory complex. Urocleidoides parodoni n. sp. resembles U. tenuis by presenting male copulatory organ with approximately 7 counterclockwise rings, but differs by the morphology of the accessory piece (lobate with a small hook-like projection versus pincer-shaped), vaginal sclerite (thumb-like subterminal projection vs. presence of a distal hook), vaginal tube (conspicuously sclerotized vs. slightly sclerotized), shape of the ventral bar (bowed vs. wide V-shaped), ventral and dorsal anchors (robust base and short shaft vs. considerably less robust base and long shaft), and hooks (slender shank with a weakly sclerotized subunit at base vs. dilated shank). Sequences of the partial 28S rDNA gene of the dactylogyrids found in this study are provided. Phylogenetic analyses showed Urocledoides spp. from Parodontidae clustering together with strong support values. This study increases the number of valid Urocleidoides species to 39, and the number of species described from parodontid hosts to four.

Elastic Stable Intramedullary Nailing Femoral Shaft Fractures in Children from Six to Ten Years Age

Background: Diaphyseal fractures of the femur (DFF) are common long-bone injuries in children and adolescents. DFF represent 1.5% of fractures in childhood. Objective: This study aimed to evaluate the clinical, functional and radiological outcome of femoral shaft fractures, which are managed by elastic stable intramedullary nailing (ESIN) in pediatric age 6-10 years. Patients and Methods: A prospective clinical randomized trial study was conducted on18 children underwent elastic stable intramedullary nailing (ESIN) for treating femoral shaft fractures at Orthopedic department, Zagazig University Hospitals during the period from April to December 2020. Plain X- rays of the femur Antero-posterior (AP) & Lateral (Lat.) views (from hip to the knee joint) was taken. Results: The time to surgery was 1.39 ± 1.12 days ranging from 1 to 6 days, the time till full union was 9.4 ± 1.76 weeks ranging from 7 to 12 weeks, more than half of the studied group (55.5%) ranged from 7 to 9 weeks and the time of full weight bearing was 9.6 ± 1.7 weeks ranging from 7 to 12 weeks, half of the studied group (50.0%) ranged from 7 to 9 weeks. So, the final outcome was 83.3% had excellent functional outcome, 11.1% of them had satisfactory functional outcome and 5.6% had poor functional outcome. 88.8% didn’t have any complications, 5.6% of them had irritation and 5.6% had superficial infection. Conclusion: ESIN is the choice treatment for transverse and short oblique shaft fractures in patients aging from 6 to 10 years old.

Modal properties of a two-stage planetary gear system with a Timoshenko beam as the intermediate shaft model

This study investigates the mode properties of a two-stage planetary gear (TSPG) system with short intermediate shafts. For this purpose, the rotating intermediate shafts in this system are considered Timoshenko beams and compared with the Euler-Bernoulli beam model. The gyroscopic effect is also considered in the TSPG model. The natural frequencies are given, and mode energy analysis is applied to quantify the importance of intermediate shafts in the total TSPG system. The vibration modes are speed dependent, and three mode types exist. The influence of the rotational speed, length of intermediate shafts and number of planets is evaluated.

Sclerobionts on tubes of the serpulid Pyrgopolon (Pyrgopolon) deforme (Lamarck, 1818) from the upper Cenomanian of Le Mans region, France

Serpulid polychaetes are described as common encrusting organisms inhabiting various substrates, but very few studies deal with tube-dwelling polychaetes as substrates for encrusters and borers. Here we focus on Pyrgopolon (Pyrgopolon) deforme, a serpulid species common in the Cenomanian of Le Mans region which acted as small solid benthic islands for colonization by invertebrates on a soft sandy/marly bottom. A relatively rich assemblage of 88 individuals was studied surficially, 15 specimens were imaged with CT, and five specimens were prepared as vacuum epoxy casts. Borings found in the tubes show relatively low diversity; nevertheless, several different, recurring shapes were recognized. Borings of the ichnogenus Rogerella are among the best preserved. The examined tubes represent the second known case of interaction between boring barnacles (Rogerella tracemakers) and serpulid worms. Short shafts perpendicular to tube surfaces are attributable to Trypanites isp. Longer, irregularly meandering tunnels resemble another form of Trypanites isp., but usually display more than one opening, suggesting Maeandropolydora. Another boring is a drop-shaped chamber with a relatively large aperture and several narrower side openings. They can be preliminarily assigned to unicamerate entobians. Among sclerozoans, encrusting oysters and cheilostome and cyclostome bryozoan colonies are the most abundant groups. Other encrusters such as serpulid and sabellid worms and foraminifers are less common, infesting fewer than 10% of tubes. Due to the high density of infestation, random distribution of boreholes and lack of signs of repair of the penetrated tube walls by the host organism, post-mortem infestation of Pyrgopolon (P.) deforme is suggested.

Comparative Study of Seismic Response of Short Columns Retrofitted by Steel Jacket, brick wall and FRP Fiber

Using inter-frame walls sometimes leads to the structure fortification in time of earthquake, but sometimes leads to plastic joint in the column which leads to the structure destruction. Therefore, the purpose of this work is to study and retrofit columns of inter-frame walls of deficient two-story structure, where he was taken in this research four models (Simple, With brick, With FRP, With Steel Jacket). In this work we look for the best retrofitting state of columns of half inter-frame wall by different states of retrofitting including FRP fibers and steel jackets. The analytical method used in this research is nonlinear elastic analysis by ABAQUS Software program. The results were extracted for the shear force with respect to the displacement of the static loads, and the displacement with respect to time was also extracted into the live loads of the four models. It was found that the presence of retrofitting of short shafts using steel jacket and FRP leads to a 3-40% increase in concrete bending framework in the section of shear strength and earthquake resistance.

The Subcortical-Allocortical- Neocortical continuum for the Emergence and Morphological Heterogeneity of Pyramidal Neurons in the Human Brain.

Human cortical and subcortical areas integrate emotion, memory, and cognition when interpreting various environmental stimuli for the elaboration of complex, evolved social behaviors. Pyramidal neurons occur in developed phylogenetic areas advancing along with the allocortex to represent 70–85% of the neocortical gray matter. Here, we illustrate and discuss morphological features of heterogeneous spiny pyramidal neurons emerging from specific amygdaloid nuclei, in CA3 and CA1 hippocampal regions, and in neocortical layers II/III and V of the anterolateral temporal lobe in humans. Three-dimensional images of Golgi-impregnated neurons were obtained using an algorithm for the visualization of the cell body, dendritic length, branching pattern, and pleomorphic dendritic spines, which are specialized plastic postsynaptic units for most excitatory inputs. We demonstrate the emergence and development of human pyramidal neurons in the cortical and basomedial (but not the medial, MeA) nuclei of the amygdala with cells showing a triangular cell body shape, basal branched dendrites, and a short apical shaft with proximal ramifications as “pyramidal-like” neurons. Basomedial neurons also have a long and distally ramified apical dendrite not oriented to the pial surface. These neurons are at the beginning of the allocortex and the limbic lobe. “Pyramidal-like” to “classic” pyramidal neurons with laminar organization advance from the CA3 to the CA1 hippocampal regions. These cells have basal and apical dendrites with specific receptive synaptic domains and several spines. Neocortical pyramidal neurons in layers II/III and V display heterogeneous dendritic branching patterns adapted to the space available and the afferent inputs of each brain area. Dendritic spines vary in their distribution, density, shapes, and sizes (classified as stubby/wide, thin, mushroom-like, ramified, transitional forms, “atypical” or complex forms, such as thorny excrescences in the MeA and CA3 hippocampal region). Spines were found isolated or intermingled, with evident particularities (e.g., an extraordinary density in long, deep CA1 pyramidal neurons), and some showing a spinule. We describe spiny pyramidal neurons considerably improving the connectional and processing complexity of the brain circuits. On the other hand, these cells have some vulnerabilities, as found in neurodegenerative Alzheimer’s disease and in temporal lobe epilepsy.

Prenatal Diagnosis and Classification of Fetal Hypospadias: The Role and Value of Magnetic Resonance Imaging.

Prenatal diagnosis and classification of hypospadias are difficult and of value for management during perinatal and neonatal periods. The conventional approach for prenatal diagnosis of hypospadias is ultrasound; however, this technique may be inconclusive in certain cases, which prompts for further exploration with magnetic resonance imaging (MRI). To investigate the role of MRI in the prenatal diagnosis and classification of fetuses with hypospadias. Retrospective. Thirty-five fetuses (median gestational age=37, range 24-39 weeks) with possible hypospadias. Single-shot fast spin echo T2-weighted imaging, fast imaging employing steady-state acquisition (FIESTA), and three-dimensional FIESTA acquired at 1.5T. Diagnosis and classification of hypospadias using MRI were performed by three experienced radiologists based on MRI features, including a short penile shaft, abnormal penile tip, penile curvature, bifid scrotum, "tulip sign," and penoscrotal transposition. The accuracy of MRI in the diagnosis and classification of hypospadias was assessed in comparison to postnatal clinical diagnosis. The interobserver agreement between radiologists was also assessed. Kendall's W test was applied to assess the interobserver agreement between radiologists. Taking postnatal clinical diagnosis as the reference standard, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. Of the 35 fetuses, 24 cases were confirmed as hypospadias through postnatal clinical diagnosis. The interobserver agreement between radiologists was substantial (Kendall's W= 0.781, P< 0.001). Of the 24 confirmed cases (13 cases of severe hypospadias and 11 cases of mild hypospadias), 22 cases were correctly diagnosed by MRI. The accuracy of MRI in the diagnosis of hypospadias, severe hypospadias, and mild hypospadias was 85.71%, 82.86%, and 80.00%, respectively. MRI has good performance in the diagnosis of fetal hypospadias. In addition, MRI could help evaluate the severity of fetal hypospadias. 3 TECHNICAL EFFICACY: Stage 2.

Theoretical and numerical study on mass flow rates of smoke exhausted from short vertical shafts in naturally ventilated urban road tunnel fires

The study focuses on the mass flow rate of the buoyancy-driven gases exhausted from the shaft in naturally ventilated urban road tunnel fires. Theoretical analyses and numerical simulations are performed. The model to predict the mass flow rate of the incoming smoke exhausted by the nearest shaft is developed by considering that the smoke is exhausted along the four sides of the shaft separately. Based on the heat balance between the incoming smoke exhausted and the total gas flow exhausted, the model to estimate the total mass flow rate exhausted from the shaft (both smoke and entrained air) is also established. Meanwhile, a series of numerical simulation in a naturally ventilated tunnel considering the heat release rate (HRR), the shaft height, shaft length and width, shaft location was carried out. The simulation results show that the shaft height has a limited contribution to the mass flow rate of the incoming smoke exhausted while a larger shaft cross-sectional area shows a favorable performance in exhausting the smoke. Further, the air entrainment into the shaft increases with both the shaft height and shaft cross-sectional area. Comparisons of the mass flow rates of the incoming smoke and the total mass flow rates exhausted between simple calculations and simulations are made, showing that the simple models perform well. Further, it is found that there exist two regimes for the total mass flow rate corresponding to different smoke modes in the shaft (complete plug-holing, plug-holing and without plug-holing), which is caused by the different driven forces in the shaft. The outcomes of this work could provide some guidance for the design of vertical shaft and smoke control in naturally ventilated tunnel in urban area.

Probing the Anisotropy of Shale by the Voltaic Response of Laser-Induced Plasma

Due to the complexity of geological structures, it is difficult to fully characterize unconventional oil and gas reservoirs in the existing geological exploitation theories and techniques. This article introduced a laser induced plasma transmission voltage (LIPTV) method for characterizing the isotropy of sandstone and anisotropy of shale. When the rocks receive a nanosecond pulsed laser, plasma is generated on the sample surface. Under the condition of applied electric field, the maximum voltage of 0.024 V can be obtained. Plasma transport was related to surface morphology and structure. The mechanism of plasma transport on the surface can be analyzed by simulating the voltage attenuation process with time. Rotation angle-dependent voltage peaks of shale presented a symmetry at the location of 180° and was an oval in polar graph, where the long shaft and the short shaft were parallel and perpendicular to bedding direction, respectively (relative range = 150%). According to the relation between the double-exponential fitting tendency and the attenuation waveform, electric field controls the transport of the carrier in the horizontal and vertical directions in shale. For sandstone, a circle was obtained in polar graph because of the isotropy (relative range = 28%). Therefore, the direction characterization supported by LIPTV method is helpful for enhancing oil recovery in petroleum industry.

La fractura del luchador de brazos

The humerus fracture produced during arm wrestling, is typically a short spiroid shaft fracture, between the middle and distal third, sometimes with a third fragment. This fracture is known as "arm wrestler´s fracture" and its usually managed surgically by plate osteosynthesis, although conservative treatment also has good results. We present a case and review of the literature on this typical fracture of a sport that has an increasing number of followers.

Evidence of Late Miocene Peri-Tibetan Aridification From the Oldest Asian Species of Sandgrouse (Aves: Pteroclidae)

The partial skeleton of a new extinct taxon, Linxiavis inaquosus, from the Liushu Formation (6-9 Ma) at the edge of the Tibetan Plateau in Gansu Province, China is the most substantial known fossil record of sandgrouse (Pteroclidae). While adding to the rapidly growing known Liushu avian fauna of vultures, falcons, pheasants, and ostrich, this new fossil is likely the oldest record of crown Pteroclidae (as a potential molecular clock calibration point), the oldest record of the group in Asia (from a probable African origin), and derives from a significant temporal gap in their Neogene history. The fossil specimen includes articulated and associated elements of the wings, shoulder girdle, vertebrae, and hind limb, exhibiting apomorphies of Columbiformes and Pteroclidae such as a notarium, and a short coracoid shaft. As part of the Linxia Basin’s diverse Hipparion fauna, Pterocles inaquosus reinforces the interpretation of the habitat as an arid savannah, associated with the uplift of the Tibetan Plateau. The holotype suggests that the arid high elevation Tibetan area habitats may have been continuously occupied since the late Miocene by sandgrouse carrying water in their modified breast feathers to their young.