Degree Of Compression Research Articles

INFLUENCE OF THE DEGREE FLOODING AND COMPRESSION CROSS-SECTION OF A HYDRAULIC STRUCTURE WITH UNSTEADY LIQUID MOVEMENT

The article is devoted to topical issues of the influence of hydraulic structures on the behavior of channel flow. Issues related to the operation of hydraulic structures located on irrigation canals were considered: - the influence of the degree of flooding on the elements of unsteady movement in open channels; - the influence of flow compression on the elements of unsteady motion in open flows. Quantitative assessment of the impact degree of flooding and compression on the elements of the flow during steady motion was carried out taking into account the recommendations of prof. Bolshakova VO, which are based on the use of the method of prof. Vasilieva OF The question influence of hydraulic structures on the behavior of the channel flow was solved using the equations of Saint-Venan by the numerical method, namely the method of run by the implicit-difference scheme. To close the system when using this method, the following conditions were taken into account: a - initial; b - left and right boundary conditions. The initial conditions are the presence of uniform movement in the channel. The left boundary condition is determined by the schedule of water supply to the channel, which has the form of a triangular hydrograph. The right boundary condition is determined by the known formula of a spillway with a wide threshold. The initial data were obtained from field observations. Quantitative assessment of the impact of flooding and flow compression on the final flow, velocity and depth results was performed. The issue of distribution of the support along the channel bed, which was formed due to the compression of the flow, was solved using the recommendations of E.V. Eremenko. The equation of flow continuity was considered - under the condition of changing the volume of water in the elementary section of the channel. The time of increase in the volume of water due to compression was determined from the formula obtained in the calculation process. Based on the condition that the time factor is a known value, it is possible to obtain a mathematical expression that determines the length of the propagation of the compression effect. Thanks to the obtained formulas, the calculated graphs of the relative maximum depth depending on the degree of flooding were constructed. With the help of these graphs it is possible to solve the problem of water supply in irrigation canals in the presence of flooding and compression of the flow (in case of unsteady movement).

DETERMINATION OF THE COMPRESSED FLOW DEPTH IN THE BRIDGEHEAD OF A SMALL BRIDGE

Introduction. Hydraulic calculation of bridges is one of the most important stages in determining its basic geometric parameters. Therefore, it should be based on the exact equations of hydraulics that characterize the behavior of water flow. Currently, the hydraulic calculation of a small bridge is based on an empirically established dependence, which is that the compressed depth under the bridge hc is associated with the support H approximate dependence hc ≈ 0,5H and is independent of the compression of the flow bridge crossing. In this work, it is theoretically proved that taking such a relationship between depths, you can get quite large inaccuracies in determining the depth in the compressed section hc, and hence in determining the speed in the calculated cross section of the bridgehead. Results. Based on the three basic laws of physics, namely: the law of conservation of mass (continuity equation), the law of conservation of energy (Bernoulli equation), the law of momentum (equation of the momentum change theorem), obtained an analytical relationship that establishes a relationship between compressed depth parameters hc and support H at different degrees of flow compression ε. Based on this dependence, an equation was obtained that establishes the relationship between the flow rate Q and the pressure in front of the bridge H. The obtained equation is similar in form to the flow equation through a wide-threshold spillway, with the difference that the flow coefficient m(ε) in the obtained equation depends on the degree of flow compression. Conclusions. The equation for determining the flow rate through the opening of a small bridge taking into account the flow compression is obtained. It is shown that the obtained equation coincides in form with the flow equation, which determines the flow through a wide-threshold spillway. The difference between these equations is that the flow coefficient m(ε) is a function of the flow compression coefficient ε. Using the boundary transition, it is obtained that m(ε) can vary from 1/3 √(2/3) to √0,5. Graphs are presented, which allow to analyze the change of hydraulic characteristics of the flow depending on the compression coefficient ε.

Electrophysiological Characteristics of Cervical Spinal Stenosis.

Objective To investigate electrophysiological characteristics of patients with cervical spinal stenosis (CSS) due to cervical disc herniation. Methods A total of 51 patients with CSS diagnosed in our hospital from January 2018 to March 2020 were selected. According to magnetic resonance imaging (MRI), the degree of spinal cord compression was divided into 1-3 grades, namely, group A (MRI grade 1), group B (MRI grade 2), and group C (MRI grade 3), with 17 cases in each group. Subsequently, we analyzed the correlation of the degree of spinal cord compression with the general information, clinical data, and electromyography (EMG) of patients. Results Compared with group A and group B, group C had the longest disease course [(48.06 ± 17.71) months], the lowest JOA score (4.59 ± 2.15), and the highest number of positive results of EMG (EMG: A/B/C, 25/51/77); there were significant differences among the 3 groups. And group C had the higher number of positive cases of both upper and lower limbs in SEP test compared with the other two groups (SEP: A/B/C: 12/18/29: χ2 = 7.559, P = 0.023). According to correlation analysis, MRI grading had no association with gender, age, and spinal canal diameter/volume but was positively correlated with disease course and negatively correlated with JOA score. Conclusion This study primarily verifies that higher MRI grade of CSS is associated with longer disease duration and lower JOA score and EMG. The obtained results secondarily demonstrate the correlation between abnormal neurological status and the MRI grade.

MATHEMATICAL STUDY OF THE INFLUENCE OF KNIFE GEOMETRY WITH ARC-LIKE CROSS-SECTIONAL SHAPE ON THE PROCESS OF LONGITUDINAL FELT CUTTING

A promising study is the design and improvement of machines for longitudinal cutting of materials with minimal energy costs to perform the technological process of cutting due to the geometry of the cutting tool. The article considers the issues of reducing energy costs for the process of longitudinal cutting when using a knife blade with an arcuate cross-section. The analysis is carried out, the effective method of the analysis of influence of size of a backlash between generators of transporting rollers and size of distance from a vertical axis of rotation of transporting rollers to an edge of a knife blade with an arc-shaped cross section on the total size to determine the necessary settings in the machine of longitudinal cutting for felt, as well as to verify the reliability of analytical and experimental models of the process of longitudinal cutting with a knife with an arcuate cross-sectional shape. To determine the total amount of losses during longitudinal cutting of the material and the number of losses due to friction of the material on the face of a fixed knife with an arcuate crosssectional shape, as well as linear cutting force, a two-factor experiment was conducted for the study model. The obtained regression equations describe the total amount of losses during longitudinal cutting of the material and the number of losses due to friction of the material on the face of a stationary knife with an arcuate cross-section, suggest the adequacy of analytical and experimental models made earlier. Also make the necessary adjustments, namely, to adjust the degree of compression of the material and set the edge of the knife blade relative to the vertical axis of the transport rollers to reduce friction losses on the edge of the knife, which in turn reduces energy costs for longitudinal cutting. Comparing the total values of losses in the longitudinal cutting of the material of a knife with one-sided sharpening and a knife with an arcuate cross-section, allows you to talk about the feasibility of using a knife with an arcuate cross-section, which will reduce energy costs for the process.

Feasibility analysis of standing wave ultrasonic - Axial magnetic field hybrid for controlling GTAW arc characteristics

In this work, based on the effect law of standing wave ultrasonic and axial magnetic field on the GTAW, a novel method of GTAW is proposed by coaxial hybrid standing wave ultrasonic and axial magnetic field, which is named as the ultrasonic and magnetic field coaxial assisted GTAW (U-M-GTAW). This paper focuses on the validation of the feasibility of standing wave ultrasonic - axial magnetic field hybrid for controlling the GTAW process. The results showed that the arc shape was obviously compressed under the action of standing wave ultrasonic. The arc compression was the most significant when the ultrasonic radiator height of 15 mm was employed. Compared with the GTAW arc, the arc shape in the luminous and dark region was respectively compressed by 32 % and 81.2 %. Under the action of an axial magnetic field, the arc shape was compressed and rotated periodically, however the compression degree of arc shape was not so obvious as that of standing wave ultrasonic compression. When the standing wave ultrasonic and axial magnetic field coaxially hybrid was used to control the arc shape, the arc shape was obviously compressed and had periodic rotation characteristics, which perfectly validated the feasibility of standing wave ultrasonic - axial magnetic field hybrid for controlling the GTAW process.

LGG-28. Rapid symptomatic improvement for a patient treated with BRAF inhibition for BRAFV600E mutated ganglioglioma

BACKGROUND: Biologically targeted agents such as the BRAF inhibitor dabrafenib are now used to treat progressive low-grade glioma (LGG), but the effect of these agents on the neurologic symptoms that accompany LGGs is poorly understood. CASE: A 21-year-old male was diagnosed with medullary ganglioglioma (GG) after presenting with persistent vertigo and positional headaches. Immunohistochemistry was consistent with BRAF V600E mutation and dabrafenib was started. The patient had resolution of his neurologic symptoms within 3 weeks of treatment initiation; surveillance MRI several months later demonstrated interval decrease in tumor size. The patient remained on therapy for 2 years. Several days after planned drug discontinuation the patient had re-emergence of persistent vertigo that impaired his ability to work. Repeat imaging two months later demonstrated an increase in tumor size and solid enhancement along tumor margins. He was restarted on dabrafenib. Within one week, he again had complete resolution of his vertigo. DISCUSSION: Gangliogliomas are comprised of mixed neuronal and glial components and associated with epilepsy, headache and other localizing neurologic symptoms. In this report, we describe clinical and radiographic response from single-therapy dabrafenib in a patient with BRAF V600E+ GG, along with a very rapid resolution of neurologic symptoms upon initiation of the drug and recrudescence shortly following cessation of therapy. The symptoms subsided within a week of restarting dabrafenib, suggesting a separate, more rapid mechanism of symptom reversal than decline in tumor size. BRAF mutations have been identified in both the neuronal and glial components of ganglioglioma, suggesting that dabrafenib may provide symptomatic relief via inhibition of abberant neuronal processes. CONCLUSION: BRAF inhibitors can rapidly improve neurological symptoms via a rapid, not yet fully elucidated mechanism. Kinetics of this response suggest it is independent of effects on tumor volume and the degree of compression to tissue surrounding the tumor.

Quantitative parameters of diffusion tensor imaging in the evaluation of carpal tunnel syndrome.

To explore the value of diffusion tensor imaging (DTI)-derived metrics in quantitative evaluation of carpal tunnel syndrome (CTS). This prospective cross-sectional study included 39 wrists from 24 symptomatic CTS patients, who underwent clinical, electrophysiological, and magnetic resonance imaging (MRI) evaluations. In addition, 10 wrists of 6 healthy participants were included as controls. Clinical and nerve conduction study (NCS) findings were evaluated and graded according to the Boston Carpal Tunnel Questionnaire (BCTQ) and the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM), respectively. We performed MRI using a 1.5 Tesla scanner. Mean diffusivity (MD), fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) of the median nerve at the distal radioulnar joint (DRUJ) (d), the inlet of the carpal tunnel (CT) at the pisiform level (i), the middle of the CT (m) and the outlet of the CT at the level of the hook of hamate (o), cross-sectional area at the inlet of the CT (iCSA), and the difference between MD and FA of the DRUJ and the outlet of CT (Delta MD and Delta FA) were measured. The CTS patients had significantly lower FA [for example, oFA: mean difference 0.09, 95% confidence interval (CI): 0.05 to 0.12] and significantly higher MD than healthy participants (for example, iMD: mean difference 0.3, 95% CI: 0.03 to 0.57). There was a negative correlation between iCSA with iFA and between mFA and oFA (-0.5<R<-0.4). There was a positive correlation between distal motor latency time and Delta MD (R=0.57) and a negative correlation between distal motor latency time and Delta FA (R=-0.51). The FA demonstrated a somewhat strong negative correlation with the Boston scores for symptom and function. The DTI-derived quantitative metrics add potential value to the evaluation of CTS. Alterations in the FA of the median nerve along the CT are the most significant features of CTS and reflect the degree of median nerve compression and clinical deficit. With a cutoff value of 0.45, FA at the carpal outlet has a sensitivity and specificity of 87.5% and 85.7% in the diagnosis of CTS, respectively.

Dynamics of Fractional Composition of Grain-and-Straw Mass Being Threshed in the Threshing Mechanism of a Combine Harvester

Introduction. The article presents the results of theoretical and experimental studies of threshing and separation processes in the threshing mechanism of the combine harvester with a digital assessment of the fractional composition of the grain-and-straw material being threshed. The obtained data will allow detecting dynamics of fractional composition of grain-and-straw mass being threshed in the threshing gap of the threshing mechanism depending on its supply. Materials and Methods. The research was carried out on a special stand in the form of a separate unit of the combine threshing mechanism. Grain-and-straw samplers were installed under each threshing section. The mass feed was changed from 1.0 to 6.0 kg/s at a straw ratio of 1:1. The obtained data were approximated using a standard procedure. Results. There was determined the amount of grain and straw passed through the threshing section screen and the rest of grain and straw entering the straw separator depending on their initial amount. For each fraction, there were determined the ratio of straw mass to grain mass, the density and thickness of the grain-and-straw heap layer on the shaking board ahead of the grates and at the beginning of the straw separator keys. The dynamics of grain-and-straw separation was identified by scanning the length of the grains with the determination of the density and compression degree of the grain-and-straw mixture layer in the threshing gap. Discussion and Conclusion. It was found that in the heap of grain-and-straw passed through a threshing section, the ratio of straw mass to grain mass decreases from 0.46 to 0.27 and density increases from 60.1 to 84.0 kg/m3. In the heap of grain-and-straw that fell on the straw separator, the ratio of the straw mass to the grain mass decreases from 11.2 to 2.0, the density increases within a small range from 21.7 to 26.4 kg/m3. Thickness of the heap layer on the shaking board in front of the cleaning sieves varies in the range 0.25‒10.20 cm, and on the straw walker ‒ 2.2‒19.8 cm when changing the supply of the total mass for threshing from 1 to 6 kg/s.

A Reliable JPEG Quantization Table Estimator

JPEG compression is a commonly used method of lossy compression for digital images. The degree of compression can be adjusted by the choice of a quality factor QF. Each software associates this value to a quantization table, which is an 8 x 8 matrix used to quantize the DCT coefficients of an image. We propose a method for recovering the JPEG quantization table relying only on the image information, without any metadata from the file header; thus the proposed method can be applied to an uncompressed image format to detect a previous JPEG compression. A statistical validation is used to decide whether significant quantization traces are found or not, and to provide a quantitative measure of the confidence on the detection.

Event-driven proto-object based saliency in 3D space to attract a robot’s attention

To interact with its environment, a robot working in 3D space needs to organise its visual input in terms of objects or their perceptual precursors, proto-objects. Among other visual cues, depth is a submodality used to direct attention to visual features and objects. Current depth-based proto-object attention models have been implemented for standard RGB-D cameras that produce synchronous frames. In contrast, event cameras are neuromorphic sensors that loosely mimic the function of the human retina by asynchronously encoding per-pixel brightness changes at very high temporal resolution, thereby providing advantages like high dynamic range, efficiency (thanks to their high degree of signal compression), and low latency. We propose a bio-inspired bottom-up attention model that exploits event-driven sensing to generate depth-based saliency maps that allow a robot to interact with complex visual input. We use event-cameras mounted in the eyes of the iCub humanoid robot to directly extract edge, disparity and motion information. Real-world experiments demonstrate that our system robustly selects salient objects near the robot in the presence of clutter and dynamic scene changes, for the benefit of downstream applications like object segmentation, tracking and robot interaction with external objects.

Cultura organizacional para el desarrollo social sostenible en microempresas Diseño de un instrumento para su evaluación

Los instrumentos para evaluar la cultura organizacional están orientados para analizarla desde un enfoque económico y se hace énfasis en que, principalmente, están dirigidos hacia pequeñas y medianas empresas. Por lo anterior, en el presente se diseñó y validó un instrumento para valorar la cultura organizacional de las microempresas hacia el desarrollo social sostenible. El instrumento se diseñó como rúbrica analítica e integró las dimensiones de planeación, liderazgo y bienestar. Posterior a su diseño, se revisó por 3 expertos y se evaluó por otros 21. Finalmente, se realizó el pilotaje del instrumento con microempresarios. La revisión y evaluación del instrumento reveló la pertenencia de ítems a las dimensiones y validez de contenido de estos (V de Aiken &gt; 0,75, VI &gt; 0,65 e IVC &gt; 0,80). El pilotaje reveló que el instrumento posee un buen grado de compresión para la población objetivo. Se concluye que el instrumento es pertinente y válido para el propósito que fue diseñado.

Left Ventricular Systolic‐Diastolic Coupling: Insight from Magnetic Resonance Dobutamine Stress

Left ventricular systolic and diastolic function are intrinsically linked, such that diastolic relaxation is influenced by the preceding systolic contraction – similar to how a springs recoil to its original shape is influenced by the degree of compression. Several clinical investigations have proposed quantifying the ratio between diastolic and systolic function to assess the coupling efficiency between the two, however, these cross‐sectional comparisons may be influenced by additional confounding factors, such as differences in tissue characteristics. Therefore, to extend our understanding, and directly examine the relationship between left ventricular systolic and diastolic coupling, we performed cardiac magnetic resonance imaging in six healthy volunteers (4F/2M, 22 ± 3 years, 24.4 ± 3.0 kg/m2) at rest and during low‐dose intravenous dobutamine infusion (2 µg/kg/min) to increase cardiac inotropy without affecting other, potentially confounding, regulators of diastolic function. Systolic and diastolic function was measured using gold‐standard tissue tagging, from three evenly spaced short axis images spanning the left ventricle from base to apex. As expected, dobutamine infusion increased peak circumferential strain (‐19.8 ± 1.6 % vs ‐21.3 ± 2.0 %, p = 0.002), systolic circumferential strain rate (CSRs: ‐96 ± 2 %/s vs ‐117 ± 7 %/s, p = 0.001), peak twist (8.2 ± 0.9 ° vs 10.7 ± 1.1 °, p = 0.002) and peak rate of systolic twist (TR: 40 ± 7 °/s vs 58 ± 8 °/s, p = 0.004). Independent of any changes in heart rate (59 ± 9 bpm vs 58 ± 9 bpm, p = 0.303) or end‐diastolic volume (171 ± 26 mL vs 170 ± 24 mL, p = 0.882), early diastolic circumferential strain rate (CSRd: 141 ± 15 %/s vs 163 ± 9 %/s, p = 0.019) and peak untwisting rate (UTR: ‐67 ± 24 °/s vs ‐88 ± 16 °/s, p = 0.018) subsequently increased. As a result, the ratio between diastolic and systolic measurements remained unchanged (CSRd/CSRs: 1.47 ± 0.14 vs 1.40 ± 0.15, p = 0.266; UTR/TR: 1.69 ± 0.54 vs 1.57 ± 0.37, p = 0.190). Taken together, these data support a growing body of evidence linking left ventricular systolic function with subsequent early diastolic relaxation and suggest that future investigations examining diastolic function should consider the influence of preceding systolic contractions.

Variant Femoral Nerve: The Path Beneath the Iliacus Muscle and Into Neuropathic Symptoms

Introduction and ObjectiveOriginating from the lumbar plexus, the femoral nerve has a native course along the anterior surface of the iliacus then travels deep to the inguinal ligament, branching into separate anterior and posterior divisions that provide innervation to the anterior thigh muscles (Figure 1). Clinically, the spatial relationship between the iliopsoas complex and the femoral nerve has been noted for the potential risk of entrapment and compressive neuropathies. Variations in the femoral nerve course following surgical and medical interventions can produce symptoms related to muscle weakness and sensory loss in patients. Relevant literature regarding variant femoral nerve distributions is most often related to aberrant slips of the iliacus muscle and following surgical or medical intervention. In this case study, we describe a variation in the descent of the femoral nerve that travels within the belly of the iliacus muscle without evidence of an aberrant slip or surgical intervention and discuss the clinical implications and appropriate non‐invasive osteopathic treatment options.MaterialsThis anatomical variation was revealed in one donor being evaluated at Sam Houston State University College of Osteopathic Medicine’s anatomy lab. The donor was previously dissected by medical students for a first‐year anatomy course. The iliacus and surrounding structures were left intact. Additional dissection necessary for this study was performed from March 2021 to April 2021.ResultsIn a 70‐year‐old male cadaver, the right femoral nerve originated from the lumbar plexus, descended, and then bifurcated (Figure 2A). Most of the femoral nerve remained within the Iliacus muscle (Figure 2B) while a small portion of the femoral nerve followed the typical course anterior to the iliacus (Figure 2C). The bulk of the femoral nerve traveled within the iliacus, exiting inferior to the inguinal ligament, then merged with the smaller portion of the nerve (Figure 2D). The left femoral nerve followed a typical course.Significance/ConclusionPrevious discussions report an aberrant slip of the iliacus splitting the femoral nerve and having the potential for nerve compression, although unlikely due to the smaller muscle belly involved. This highlighted variant is significant because the bulk of the femoral nerve remains beneath the iliacus as it crosses over the pubic eminence. This pathway would be predisposed to a greater degree of compression against the pubic eminence, with potential for certain movements to increase these forces.This patient presentation is hypothesized to include anterior thigh weakness during hip flexion and knee extension activities, such as stair‐climbing, as well as sensory loss to the anteromedial thigh and medial leg via the saphenous nerve. Sensation to the lateral thigh should remain intact as the lateral femoral cutaneous nerve would be unaffected. conservative treatments, such as osteopathic manipulative techniques, could be an effective form of treatment. Techniques including counterstrain to the psoas and iliacus or muscle energy to the hip flexors could lessen such nerve compression and improve patient symptoms.Awareness of this variation could provide clinicians with another potential diagnosis to consider when managing femoral neuropathy, as well as rationale for a non‐invasive treatment option.

Association of hydromyelia and acute compressive myelopathy caused by intervertebral disc extrusion in dogs.

BackgroundHydromyelia is a common magnetic resonance imaging (MRI) finding associated with compressive myelopathy caused by intervertebral disc extrusion (IVDE).ObjectivesTo describe the MRI features of hydromyelia and explore its relationship to clinical history, neurological severity, and the duration of cord compression.AnimalsNinety‐one client‐owned dogs with a focal compressive myelopathy secondary to thoracolumbar IVDE.MethodsA retrospective observational study was conducted in which MRIs were blindly evaluated to grade and localize hydromyelia and measure the degree of spinal cord compression. Duration and severity of clinical signs were recorded. Differences between hydromyelia grades in these variables were statistically assessed using a Wilcoxon and Kruskal Wallis test. Receiver operator curve analysis was used to determine the sensitivity and specificity for duration of clinical signs to predict the presence of hydromyelia.ResultsHydromyelia was identified at sites of IVDE in 84 of 91 dogs. An absence of hydromyelia was associated a with statistically longer duration of clinical signs (mean 73.1, IQR 76 days) when compared to cases with mild (mean 17.7, IQR 7.25 days, P = .006) or severe (mean 17.9, IQR 10.25 days, P = .006) hydromyelia. Duration of clinical signs <14 days was 78.6% sensitive and 85.7% specific for predicting the presence of hydromyelia.Conclusions and Clinical ImportanceThe MRI finding of hydromyelia might be a predictor of lesion chronicity in focal IVDE, helping to guide planning of hemilaminectomy surgery.

Multidata Analysis Based on an Artificial Neural Network Model for Long-Term Pain Outcome and Key Predictors of Microvascular Decompression in Trigeminal Neuralgia

To investigate use of multidata analysis based on an artificial neural network (ANN) to predict long-term pain outcomes after microvascular decompression (MVD) in patients with trigeminal neuralgia (TN) and to explore key predictors. Perioperative and long-term follow-up multidata of 1041 patients with TN who received MVD surgery at Hangzhou First People's Hospital from March 2013 to May 2018 were collected to construct an ANN model for prediction. The prediction results were compared with the actual follow-up outcomes, and the variables in each input layer were changed to test the effectiveness of ANN and explore the factors that had the greatest impact on prediction accuracy. The ANN model could predict the long-term pain outcomes after MVD in patients with TN with an accuracy rate of 95.2% and area under the curve of 0.862. Four factors contributed the most to the predictive performance of the ANN: whether the neurovascular offending site of the trigeminal nerve corresponded the region of facial pain, immediate postoperative pain remission after MVD, degree of nerve compression by culprit vessels, and the type of culprit vessels. After these factors were sequentially removed, the accuracy of the ANN model decreased to 74.5%, 78.6%, 87.2%, and 90.1%, while the area under the curve was 0.705, 0.761, 0.793, and 0.810. The ANN model, constructed using multiple data, predicted long-term pain prognosis after MVD in patients with TN objectively and accurately. The model was able to assess the importance of each factor in the prediction of pain outcome.

Investigation on Hydration and Deformation Characteristics of Shale Using X-ray Computed Tomography

The physical and mechanical properties of shale are significant for completion engineering and fracturing design for shale oil and gas production. To further study the water effect and the deformation characteristics of shale, some cylindrical specimens were soaked at three periods (0, 20, and 60 days), the in situ uniaxial compression tests were conducted, and the CT technique was used at different hydration and loading stages. Based on the CT results, the image gray variance value in each hydration specimen was extracted; the evolution results show that the water imbibition has a significant influence on the structure of shale in the early soaking stage, and the influence degree is more evident in the external region. Moreover, the water influence on the mechanical property of shale was analyzed by comparing the failure characteristics of specimens with and without hydration; the CT results show that the hydration treatment affects the failure mode of shale. In addition, a new method based on the CT image was proposed to calculate the lateral strain; the evolution of the axial stress-strain curve reveals that the expansion phenomena exist before failure, and the evolution process includes four stages. At last, the differences in the deformation degree were discussed by analyzing the volumetric strain at different CT scanning layers; the results reflect the expansion or compression degree along with the specimen height. Those conclusions can help us further understand the water effect and the deformation characteristics of shale oil and gas reservoirs.

Osteoporotic vertebral compression fracture accompanied with thoracolumbar fascial injury: risk factors and the association with residual pain after percutaneous vertebroplasty

BackgroundTo explore the risk factors involved in the induction of thoracolumbar fascia (TLF) injury by osteoporotic vertebral compression fracture (OVCF), and the association between the residual pain after percutaneous vertebroplasty (PVP) and fascial injury.MethodsA total of 81 patients with single-segment OVCF, treated between January 2018 and January 2020 were included. The patients were grouped according to the existence of TLF injury. The patients’ general, clinical, and imaging data were accessed.ResultsThere were 47 patients in the TLF group and 34 in the non-injury group (NTLF group). In the TLF group, BMI (Body mass index) was significantly lower, while the prevalence of hypertension and sarcopenia were significantly higher (P < 0.05). The vertebral compression degree was higher, and the kyphosis angle of the injured vertebra was greater in the TLF group (P < 0.05). Cobb’s angle was not significantly different between groups. At 3-d after the operation, the VAS (Visual analogue scale) was 4.64 ± 1.78 and 3.00 ± 1.71, and the ODI (Oswestry disability index) was 67.44 ± 11.37% and 56.73 ± 10.59% in TLF and NTLF group, respectively (P < 0.05). However, at 3-m after the operation, the differences in the VAS score and the ODI between groups were not statistically significant. The area of fascial edema was not significantly associated with the pre- and post-operative VAS or ODI, but was positively correlated with the vertebral body compression degree (R = 0.582, P = 0. 029).ConclusionResidual back pain after PVP is associated with TLF injury. Low BMI, hypertension and sarcopenia are risk factors of TLF injury, and sarcopenia may be the major factor.

Surgical treatment of patients with cerebral metastases in the motor area

Introduction. The surgical stage takes an important place in the complex treatment of patients with cerebral metastases of malignant tumors. In general, all efforts during surgical intervention should be aimed at restoring a good functional status, since severe neurological symptoms can deprive patients of the opportunity to continue complex treatment, which will negatively affect overall survival. The most pronounced neurological symptoms are observed in patients with metastases in the motor area. In this article, we tried to substantiate the need for surgery of cerebral metastases in patients with severe motor deficits, evaluate the results of surgical treatment and also to develop optimal surgical removal techniques.The study object – to assess the effectiveness of surgical removal of metastases in the motor cortex by evaluating the dynamics of motor function recovery and regression of paroxysmal symptoms.Materials and methods. An analysis of the surgical treatment of 18 patients with metastases in the motor area was carried out. Tumor localization was verified using magnetic resonance imaging, before surgery, neuronavigation system Brainlab during surgery. Мagnetic resonance tractography made it possible to assess the localization and degree of compression of the fibers of the cortico-spinal tract. Functional monitoring was not performed during the operation. The operations were performed using a ZEISS OPMI PENTERO 800 microscope.Results. Recovery of motor function after surgery was noted in 17 (94.5 %) cases. It was complete or partial. With metastases of a solid, solid-necrotic, solid-cystic structure, regression of pyramidal symptoms developed gradually, starting from 4 days after surgery. As a rule, rehabilitation therapy (therapeutic exercise, massage, electromyostimulation) is carried out on patients from 3 days after surgery, which accelerated the recovery process. The maximum effect developed on the 15th day after the operation. Faster recovery of motor function was observed in patients with large cystic metastases who underwent surgery in the volume of Ommaya reservoir implantation. They began to recover motor function a few hours after awakening. Regression of paroxysmal symptoms was noted in all cases. Although the patients continued to take anticonvulsants. The observation period was 6 months.Сonclusion. Surgical removal of cerebral metastases in the motor area allows achieving complete or partial regression of neurological symptoms. At the same time, the recovery period is short – from several hours to 14 days. It becomes possible to cancel glucocorticoids 7–10 days after the operation. Conditions are being created for the continuation of complex treatment of patients previously considered incurable.

The Use of Internet of Things and Cloud Computing Technology in the Performance Appraisal Management of Innovation Capability of University Scientific Research Team.

This study aims to speed up the progress of scientific research projects in colleges and universities, continuously improve the innovation ability of scientific research teams in colleges and universities, and optimize the current management methods of performance appraisal of college innovation ability. Firstly, the needs of the innovation performance evaluation system are analyzed, and the corresponding innovation performance evaluation index system of scientific research team is constructed. Secondly, the Internet of Things (IoT) combines the Field Programmable Gate Array (FPGA) to build an innovation capability performance appraisal management terminal. Thirdly, the lightweight deep network has been built into the innovation ability performance assessment management network of university scientific research teams, which relates to the innovation performance assessment index system of scientific research teams. Finally, the system performance is tested. The results show that the proposed method has different degrees of compression for MobileNet, which can significantly reduce the network computation and retain the original recognition ability. Models whose Floating-Point Operations (FLOPs) are reduced by 70% to 90% have 3.6 to 14.3 times fewer parameters. Under different pruning rates, the proposed model has higher model compression rate and recognition accuracy than other models. The results also show that the output of the results is closely related to the interests of the research team. The academic influence score of Team 1 is 0.17, which is the highest among the six groups in this experimental study, indicating that Team 1 has the most significant academic influence. These results provide certain data support and method reference for evaluating the innovation ability of scientific research teams in colleges and universities and contribute to the comprehensive development of efficient scientific research teams.

Degeneration of the Sensorimotor Tract in Degenerative Cervical Myelopathy and Compensatory Structural Changes in the Brain.

Degenerative cervical myelopathy is a progressive neurodegenerative disease, that has become increasingly prevalent in the aging population worldwide. The current study determined the factors affecting degeneration in the sensorimotor tract with degenerative cervical myelopathy and its relationship with brain structure. We divided patients into hyperintensity (HS) and non-hyperintensity (nHS) groups and measured the fractional anisotropy and apparent diffusion coefficients of the lateral corticospinal tract (CST), fasciculus gracilis and fasciculus cuneatus (FGC). Voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) techniques were used to estimate brain structure changes. Correlation of the modified Japanese Orthopaedic Association (mJOA) score, light touch, pinprick, motor score, and fractional anisotropy (FA) ratios of the CST at different levels were analyzed. Compared to healthy controls, the FA ratios of CST in the HS and nHS groups were decreased at all levels, and the apparent diffusion coefficient (ADC) ratio was increased only at C4/5 levels in the HS group. The FA ratio of FGC was decreased at the C3/4 and C4/5 levels in the HS group and only decreased at the C4/5 level in the nHS group. The ADC ratio was decreased only at the C4/5 level in the HS group. VBM analysis revealed that the volume of the precentral gyrus, postcentral gyrus, and paracentral lobule increased in patients compared to controls. TBSS analysis found no statistical significance between the sensory and motor tracts in white matter. The volume of clusters in HS and nHS groups negatively correlated with the C1/2 FA ratio of the CST. The results showed that the degeneration distance of the CST was longer than the FGC, and the degeneration distance was related to the degree of compression and spinal cord damage. Structural compensation and the neurotrophin family may lead to enlargement of the brain.