Decompression Phase Research Articles

Compaction behavior of freeze-dried and spray-dried trypsin/lactose particulate systems

Development of oral solid dosage forms containing biologics has attracted intense interests recently due to the high patient convenience and the commercial potential of related products. The aim of this study was to understand how the difference in the particle properties prepared using two different drying principles, i.e. freeze-drying and spray-drying, may influence the compaction behavior of particulate protein systems. Here, trypsin was used as a model protein drug and lactose as a filler. The raw freeze-dried (FD) powder composed mostly of trypsin and lactose was dissolved in Milli-Q water and processed by spray-drying to produce spray-dried (SD) powder. Meanwhile, the raw FD powder was micronized by a ball mill into fine ball-milled (BM) powder with a comparable particle size to that of SD powder. Next, the FD, BM and SD powders were characterized with regard to morphology, residual moisture content (RMC), solid form, and surface chemistry using scanning electron microscope (SEM), thermogravimetric analysis (TGA), X-ray powder diffraction (XRPD), and X-ray photoelectron spectroscopy (XPS), respectively. Subsequently, a compaction simulator was employed to prepare tablets within the compaction pressure range of 25 to 400 MPa. The results showed that FD and BM powders could be compressed into tablets within the investigated compaction pressure range. In contrast, tablets compacted from SD powder displayed capping/lamination tendency under high compaction pressures and thus had poor tabletability. XPS analyses revealed that there were more surface enrichments of trypsin in the SD powder compared to that of FD powder. It implies that there would be more hydrophobic inter-particulate trypsin-trypsin interactions and less hydrophilic lactose-lactose interactions during the compression of SD powder compared to the compaction of FD powder. The weak hydrophobic inter-particulate trypsin-trypsin interactions may not be maintained during the decompression phase especially when compacted at high compaction pressure ranges, resulting in capping/lamination of the SD tablets. This study demonstrates that the two drying principles, i.e. freeze-drying and spray-drying, can result in different particle properties of biologics, which can in turn influence the tabletability of the resulting solid materials.

Role of Hyperbaric Oxygen Therapy in Traumatic Brain Injury: A Systematic Review of Randomized Controlled Trials

Abstract Background Traumatic brain injury (TBI) is a significant public health concern. Standard care involves conservative management and pharmacological and surgical interventions. Hyperbaric oxygen therapy (HBOT) has emerged as a potential treatment for TBI, with varied findings in the literature. Our systematic review aims to comprehensively assess the efficacy and safety of HBOT in TBI management, addressing existing knowledge gaps and providing insights for clinical practice and future research. Methods A systematic literature search was performed in PubMed, SCOPUS, Central Cochrane Registry of Controlled Trials (The Cochrane Library), and ScienceDirect databases for the role of HBOT in TBI. We included studies involving randomized controlled trials (RCTs). Quasi-randomized controlled studies, prospective, retrospective observational studies, case series, case reports, letters, editorials, comments, animal studies, and studies from non-English literature were excluded. Results After identifying 306 articles, we narrowed it to 8 for qualitative synthesis. The studies were categorized into subgroups: those on patients with an acute history of cerebral injury and those with a history of mild TBI. The combined RCTs involved 651 patients (326 in the first subgroup, 325 in the second). Despite a uniform HBOT session duration of 60 minutes, variations in compression, decompression phases, and pressure used (1.5ATA to 2.5ATA) hindered meta-analysis comparability. Outcome measures differed, complicating comparisons. Overall, HBOT appears beneficial in the first group and less so in the second. Complications are primarily pulmonary, which include dyspnea, cyanosis, hyperoxic pneumonia, and increased fraction of inspired oxygen requirement. Conclusion Our study encountered challenges in reaching definitive conclusions due to outcome variability among the included studies. Despite mixed results, HBOT shows potential benefits for acute TBI patients. Conversely, our findings suggest the limited efficacy of HBOT for chronic traumatic brain injury patients. Further research is crucial, particularly exploring diverse HBOT treatment protocols to establish optimal pressure levels and the required number of sessions for effective outcomes

Comprehensive Cardiopulmonary Resuscitation Training for Foreign Medical Students

The purpose of this study was to assess acquired knowledge and practical skills in foreign medical students (FMS) after theoretical and practical training in cardiopulmonary resuscitation.Material and methods. We conducted a prospective randomized trial «Simulation-based CPR training among international medical students: perspectives for medical education» envolving students undergoing training in the 31.05.01 specialty — General Medicine in English. Sealed envelope randomization was used to assign the participants (N=71) to 3 groups. European Resuscitation Council (ECR) educational Guidelines for Resuscitation was studied by students of all 3 groups. Group 1 (N=21) students did not receive additional training materials and practices. Group 2 (N=25) students were additionally provided with a link to a video lesson on CPR on the ECR Youtube channel. Students from Group 3 (N=25) were additionally involved in developing 3 mind maps: on the anatomy and physiology of the heart and CPR algorithm. All participants underwent theoretical training at the 1st stage, and «Basic Cardiopulmonary Resuscitation and Automated External Defibrillation (AED)» simulation training at the second stage. At the end of the course, students’ practical skill in performing continuous chest compressions were examined.Results. The majority of examinees passed the ECR platform test on the first or second attempt. The participants of the simulation course demonstrated high learning efficiency: there were no statistically significant differences between the groups in the number and average frequency of compressions performed. Almost all participants correctly performed hand placement in the center of the chest for chest compression. Decompression phase efficiency reached 71–77% (P=0.811) in all groups. The majority of examinees performed chest compressions to the required depth and with the recommended frequency (P=0.62).Conclusion. The educational project initiated by foreign students yielded positive results: acquired knowledge of CPR algorithm, gained essential techniques of performing chest compressions and giving rescue breaths, retained skills in using automated external defibrillator, as well as teamwork skills.

Enhancement on photobiological hydrogen production from corn stalk via reducing hydrogen pressure in bioreactors by way of phased decompression schemes

In this project, it was verified that properly reducing the bioreactor hydrogen partial pressure (HPP) could significantly enhance the photo-fermentative hydrogen production (PFHP) by corn stalk. The maximal cumulative hydrogen yield (CHY) of 82.37 mL/g was obtained under full decompression to 0.4 bar, which was 35% higher than that without decompression. To increase CHY and save the pressure control cost, 12-hour, 24-hour and 36-hour decompression schemes were provided, and the optimal decompression phase in fermentation under each scheme was investigated. The 12-hour decompression scheme was suitable for 24–36 h of fermentation; the 24-hour decompression scheme implemented within 12–36 h of fermentation had a more desirable CHY; when adopting the 36-hour decompression scheme, operation during 12–48 h yielded a CHY of 81.70 mL/g that approximated whole process decompression. The strategies of decompression at the appropriate phase of fermentation were innovative, which offered a new option for optimizing PFHP economically.

Vertical and Leg stiffness modeling during running: effect of speed and incline.

A spring mass model is often used to describe human running, allowing to understand the concept of elastic energy storage and restitution. The stiffness of the spring is a key parameter and different methods have been developed to estimate both the vertical and the leg stiffness components. Nevertheless, the validity and the range of application of these models are still debated. The aim of the present study was to compare three methods (i.e., Temporal, Kinetic and Kinematic-Kinetic) of stiffness determination. Twenty-nine healthy participants equipped with reflective markers performed 5-min running bouts at four running speeds and eight inclines on an instrumented treadmill surrounded by a tri-dimensional motion camera system. The three methods provided valid results among the different speeds, but the reference method (i.e., Kinematic-Kinetic) provided higher vertical stiffness and lower leg stiffness than the two other methods (both p<0.001). On inclined terrain, the method using temporal parameters provided non valid outcomes and should not be used. Finally, this study highlights that both the assumption of symmetry between compression and decompression phases or the estimation of the vertical displacement and changes in leg length are the major sources of errors when comparing different speeds or different slopes.

U–Pb SHRIMP zircon dating and geochemistry of metapelites from the Shillong Meghalaya Gneissic Complex, NE India: Implications for nature of protolith and tectonic setting

The Sonapahar area of Shillong Meghalaya Gneissic Complex (SMGC) is an extension of the Central India Tectonic Zone within the Precambrian Indian shield. The study area mainly consists of metapelites, basic granulites, granitic gneisses and high-grade gneisses as metamorphic imprints. U–Pb SHRIMP zircon dating yields a late Paleoproterozoic age of 1672 ± 6 Ma, which is age of the metapelites protolith. The petrochronology and geochemistry of metapelites and granitic gneiss basement rocks have been studied to learn more about the SMGC's tectonic environment, involvement in the supercontinent cycle, crustal development and geodynamic context. In the NCKFMASHTO system, phase equilibria modelling of metapelites shows peak metamorphic stage at P-T conditions of 8.25 kbar/ 820°C. Cordierite is formed during retrograde metamorphism during the decompression phases. The negative anomalies in Nb, Sr and Ti indicate that crustal sources played a significant role in magmatic emplacement. Geochemical data from metapelites indicate that protoliths were trachy-andesitic in nature, generated during the syn-orogenic environment by subduction tectonism. The SMGC experienced significant tectonic activity throughout the Paleoproterozoic age when the subduction tectonic setting coincided with orogenic activity. The presence of Paleoproterozoic age in the study area, as well as Southwestern Australia and East Antarctica correlates the Sonapahar granulite with the Columbia supercontinent history.

Clinical Considerations for Implanted Neurological Devices in Patients Undergoing Hyperbaric Oxygen Therapy: A Case Report and Review of Manufacturer Guidelines

Patients with implanted medical devices are increasingly referred for hyperbaric oxygen therapy (HBOT), and the safety of exposing some of these devices to hyperbaric environments has not previously been explored. There is a paucity of evidence surrounding the management of implanted neurological devices such as neurostimulators and intrathecal drug delivery (IDD) pumps in the context of HBOT. However, these devices can be expected to harbor unique risks; for example, vacant space in the reservoir of an implanted IDD pump may change in pressure and volume during the compression and decompression phases of HBOT, resulting in a damaged or dysfunctional device. We present the case of a 27-year-old woman with cerebral palsy referred for HBOT to manage a necrotizing soft tissue infection cultured from a dehiscent abdominal wound at the previous implantation site of an intrathecal baclofen pump. An HBOT protocol was ultimately chosen in partnership with the patient and her family, but treatment was not performed due to a paucity of evidence that the implanted IDD pump could safely withstand hyperbaric exposure. In this review, we have synthesized manufacturer recommendations regarding the management of implanted neurological devices before, during, and after HBOT to inform future decision-making in this setting. Among these recommendations, we highlight that neurostimulators should be switched off for the duration of HBOT and implanted pumps should be refilled prior to each treatment session to minimize empty reservoir space.

Generative Adversarial and Dual Layered Deep Classification Techniques for Improving Block Constructions in Public Cloud

This paper provides the Generative Adversarial and Dual Layered Deep Classification techniques to improve the drawbacks in the methods of Absolute Moment BTC (AMBTC) technique in reconstruction error rate of standard BTC model. The image blocks generation and compression are the main phases of BTC model. This can be applied for both colour images and grey scale images. However, the conventional BTC procedures lacks for edge reconstructions and noise reductions in the output images. The first technique GABTC is developed with multi-layered Deep Neural Network (DNN) structures with GA neural models. The integration of both GA models and BTC principles improve the quality of block constructions and reconstructions significantly. The second proposed work is adopted the Dual layered Deep Classification Technique. Handling the image database with minimal storage complexity, minimal computational complexity and optimal quality is a significant task. To obtain these solutions, many image processing techniques are evolved. In the domain, image compression and decompression are more needed at any cost for effectively handling the complex image databases. E-Learning resources are widely used around the internet based knowledge sharing environments. In the E-Learning environment, multiple types of data resources are managed. Particularly, organizing the images is more crucial task where multiple qualities of images are appeared inside the E-Learning network databases. This problem expects solutions from effective image compression techniques. Block Truncation Coding (BTC) and Absolute Moment BTC (AMBTC) are the techniques provide useful and easy implementations of E-Learning based image compression platform. At the same time, they are limited to image dissimilarity rate. To maintain the quality of images in both compression and decompression phases, multilevel image analysis models and training phases are required. In this regard, this proposed system develops a Dual Layered Deep Classification and Truncation (DLDCT) technique. DLDCT comprises the baseline benefits of BTC, multi-layered Support Vector Machine (SVM) units and Deep Layered Convolutional Neural Network (DLCNN) for producing classified range of image pixels and compressing the images under controlled circumstances. This proposed DLDCT makes the image compression and decompression with determined observations. This reduces real time errors occur during image reconstruction phases. This proposed system has been implemented and compared with existing works with respect to significant performance parameters.

Negative porosity issue in the Heckel analysis: A possible solution

A parameterization of compaction simulator generated dynamic compression profile with a few grams of powder provides important information about the material deformation and compact elasticity. The Heckel equation is by far the most popular choice among pharmaceutical scientists for such parametrization. A general approach of Heckel analysis uses pycnometric powder density (ρP0) for relative density calculation. However, as ‘in-die’ tablet bulk density at applied compression pressure (ρBP) becomes greater than or equal to the measured ρP0, the general approach typically poses a negative porosity challenge at high compression pressure regions. It is only theoretically possible to have a tablet with zero or negative porosity. Negative porosity may be detected during ‘in-die’ compression analysis, but it will not exist after ejection of the tablet in practical aspect. Thus, the present work proposes a new approach to using pycnometric tablet density (ρPP) in the relative density calculations of Heckel analysis. This ρPP may be a better representation of actual tablet particle volume, as it is composed of non-accessible intra-particulate pores, which are broken under applied compression pressure. A new approach showed its immunity for Heckel high-pressure negative porosity. It enables the utilization of the compression and decompression phases of dynamic compression profiles to evaluate macroscopic compaction performance. The proposed approach was validated with a reported modified Heckel approach. The Heckel parameters computed with both methodologies for microcrystalline cellulose and lactose were not statistically different. However, a modified Heckel approach was unable to compute Heckel parameters of poorly compacting starch unlike the new approach. A modified Heckel approach became invalid during starch compaction at low compression pressures (below 400 MPa), where starch was forming weaker but still intact tablets. Certainly, a complete Heckel profiling with a new approach could save time and costs in an early development stage for designing and screening scientifically based lead prototype formulations.

Compression–decompression modulus (CDM) – an alternative/complementary approach to Heckel’s analysis

The novel modulus-based approach was developed to characterize the compression behavior of the materials and how it results into tablet mechanical strength (TMS) of the final tablet. The force–displacement profile for the model materials (Vivapur® 101, Starch 1500®, Emcompress®, and Tablettose® 100) was generated at different compression pressures (100, 150, and 200 MPa) and speeds (0.35, 0.55, and 0.75 m/s) using compaction emulator (Presster™). A generated continuous compression profile was evaluated with Heckel plot and the proposed material modulus method. The computed compression parameters were qualitatively and quantitatively correlated with TMS by principal component analysis and principal component regression, respectively. Compression modulus has negatively correlated, while decompression modulus is positively correlated to TMS. Proposed modulus descriptors are independent of particle density measurements required for the Heckel method and could overcome the limitations of the Heckel method to evaluate the decompression phase. Based on the outcome of the study, a two-dimensional compression and decompression modulus classification system (CDMCS) was proposed. The proposed CDMCS could be used to define critical material attributes in the early development stage or to understand reasons for tablet failure in the late development stage.

White Blood Cells, Platelets, Red Blood Cells and Gas Bubbles in SCUBA Diving: Is There a Relationship?

(1) Background: SCUBA diving can influence changes of several hematological parameters (HP) but the changes of HP in the decompression phases are still unclear. The aim of this study was to investigate any possible relationship between HP and predisposition to inert gas bubble formation after a single recreational dive. (2) Methods: Blood, obtained from 32 expert SCUBA divers, was tested for differences in white blood cells (WBC), granulocytes (GRAN), lymphocytes (LYM), and monocytes (MONO), red blood cells (RBC), and platelets (PLT) between bubblers (B) and non-bubblers (NB). (3) Results: We found inter-subject differences in bubble formation (considering the same diving profile performed by the divers) and a statistically significant higher number of total WBC, GRAN and LYM in NB as compared to the B divers in the pre and in the post diving sample, while no statistical differences were found for MONO and PLT. In addition, we did not find any statistically significant difference between NB and B in RBC. (4) Conclusions: Our results, even if in absence of investigated anti-inflammatory markers, could indicate a relationship between low WBC numbers and bubble formation. This aspect may explain a possible cause of inter-subject differences in bubble formation in divers performing the same dive profile.

A safety assessment of a 300-meter saturation dive at sea by mental ability and performance efficacy

High pressure is an environmental characteristic of the deep sea that may exert critical effects on the physiology and mental abilities of divers. In this study we evaluated the performance efficacy and mental ability of four divers during a 300-meter helium-oxygen saturation dive at sea. Spatial memory, 2D/3D mental rotation functioning, grip strength, and hand-eye coordination ability were examined for four divers during the pre-dive, compression, decompression, and post-dive phases. The results showed that both the reaction time and the correct responses for the mental rotation and hand-eye coordination were slightly fluctuated. In addition, there was a significant decline in the grip strength of the left hand. It is concluded that the performance efficacy and mental ability of divers were virtually unaffected during 300-meter helium-oxygen saturation diving at sea.

Metamorphic evolution of the pelitic and mafic granulites from Daltonganj, Chhotanagpur Granite Gneiss Complex, India: Constraints from zircon U–Pb age and phase equilibria modelling

The Daltonganj region is located on the northwestern extension of the Chhotanagpur Granite Gneiss Complex in the eastern Indian Peninsula, which is characterized by pelitic and mafic assemblages of granulite facies rock. The pelitic granulites contain garnet, cordierite, biotite, plagioclase, K‐feldspar, sillimanite, and quartz. Petrographical interpretations divulge prograde and retrograde metamorphic events within mafic granulites, which consist of clinopyroxene, orthopyroxene, amphibole, plagioclase, biotite, and quartz. Field observation, petrography, phase equilibrium modelling, and U–Pb zircon geochronology of the pelitic granulites reveal two stages of metamorphic events along the clockwise P–T path. Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA‐ICP‐MS) zircon U–Pb age dating of pelitic granulites shows the detrital zircon ages from ~1,734 Ma to 1,677 Ma, and the possible metamorphic domains show the weighted mean age of 1,638 ± 22 Ma, which represents the timing of metamorphism. Subsequently, the magmatic emplacement of mafic granulites was recorded at 1,629 ± 6 Ma age by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA‐ICP‐MS) zircon U–Pb dating which coincide with the timing of metamorphism of the pelitic granulite. Phase equilibrium modelling in the NCKFMASHTO system divulges the pre‐peak metamorphic stage at ~3.2 kbar and ~620°C and the first stage which is characterized by a peak metamorphic condition that ranges from 7.40 to 9.10 kbar and from 815 to 835°C during ~1,638 Ma with the mineral assemblage of garnet + sillimanite + biotite + plagioclase + K‐feldspar + melt + quartz + ilmenite. Sequentially, the retrograde metamorphism is observed by a nearly isothermal decompression stage at ~4.0 kbar/~790°C after 1,638 Ma, due to the appearance of garnet + cordierite + biotite + plagioclase + K‐feldspar + melt + quartz + ilmenite + magnetite. The formation of cordierite is due to the decompression and dehydration melting phases. The Nb, Sr, and Ti negative anomalies suggest their generation from crustal sources. The geochemical analyses constrain that the sedimentation of pelitic sediments was recorded along the convergent margin and encountered by a subduction‐related tectonic setting. The geochemical interpretation provides significant evidence that the protoliths of pelitic granulites were derived from the Singhbhum Mobile Belt, Mahakoshal Supracrustal Belt, and Bundelkhand Craton, while their metamorphism was processed by the continent–continent collision and followed by exhumation.

Mechanical active compression-decompression versus standard mechanical cardiopulmonary resuscitation: A randomised haemodynamic out-of-hospital cardiac arrest study

BackgroundActive compression-decompression cardiopulmonary resuscitation (ACD-CPR) utilises a suction cup to lift the chest-wall actively during the decompression phase (AD). We hypothesised that mechanical ACD-CPR (Intervention), with AD up to 30 mm above the sternal resting position, would generate better haemodynamic results than standard mechanical CPR (Control). MethodsThis out-of-hospital adult non-traumatic cardiac arrest trial was prospective, block-randomised and non-blinded. We included intubated patients with capnography recorded during mechanical CPR. Exclusion criteria were pregnancy, prisoners, and prior chest surgery. The primary endpoint was maximum tidal carbon dioxide partial pressure (pMTCO2) and secondary endpoints were oxygen saturation of cerebral tissue (SctO2), invasive arterial blood pressures and CPR-related injuries. Intervention device lifting force performance was categorised as Complete AD (≥30 Newtons) or Incomplete AD (≤10 Newtons). Haemodynamic data, analysed as one measurement for each parameter per ventilation (Observation Unit, OU) with non-linear regression statistics are reported as mean (standard deviation). A two-sided p-value < 0.05 was considered as statistically significant. ResultsOf 221 enrolled patients, 210 were deemed eligible (Control 109, Intervention 101). The Control vs. Intervention results showed no significant differences for pMTCO2: 29(17) vs 29(18) mmHg (p = 0.86), blood pressures during compressions: 111(45) vs. 101(68) mmHg (p = 0.93) and decompressions: 21(20) vs. 18(18) mmHg (p = 0.93) or for SctO2%: 55(36) vs. 57(9) (p = 0.42). The 48 patients who received Complete AD in > 50% of their OUs had higher SctO2 than Control patients: 58(11) vs. 55(36)% (p < 0.001). ConclusionsMechanical ACD-CPR provided similar haemodynamic results to standard mechanical CPR. The Intervention device did not consistently provide Complete AD. Clinical trial registrationClinicalTrials.gov identifier (NCT number): NCT02479152. The Haemodynamic Effects of Mechanical Standard and Active Chest Compression-decompression During Out-of-hospital CPR.

Clemastine improves electrophysiologic and histomorphometric changes through promoting myelin repair in a murine model of compression neuropathy

Compression neuropathies are common and debilitating conditions that result in variable functional recovery after surgical decompression. Recent drug repurposing studies have verified that clemastine promotes functional recovery through enhancement of myelin repair in demyelinating disease. We investigated the utility of clemastine as a treatment for compression neuropathy using a validated murine model of compression neuropathy encircling the compression tube around the sciatic nerve. Mice received PBS or clemastine solution for 6 weeks of compression phase. Mice taken surgical decompression received PBS or clemastine solution for 2 weeks of decompression phase. Electrodiagnostic, histomorphometric, and Western immunoblotting analyses were performed to verify the effects of clemastine. During the compression phase, mice treated with clemastine had significantly decreased latency and increased amplitude compared to untreated mice that received PBS. Histomorphometric analyses revealed that mice treated with clemastine had significantly higher proportions of myelinated axons, thicker myelin, and a lower G-ratio. The expression levels of myelin proteins, including myelin protein zero and myelin associated glycoprotein, were higher in mice treated with clemastine. However, the electrophysiologic and histomorphometric improvements were observed regardless of clemastine treatment in mice taken surgical decompression. Mice treated with clemastine during compression of the sciatic nerve demonstrated that clemastine treatment attenuated electrophysiologic and histomorphometric changes caused by compression through promoting myelin repair.

Image Compression Approach using Segmentation and Total Variation Regularization

In this paper we present a hybrid model for image compression based on segmentation and total variation regularization. The main motivation behind our approach is to offer decode image with immediate access to objects/features of interest. We are targeting high quality decoded image in order to be useful on smart devices, for analysis purpose, as well as for multimedia content-based description standards. The image is approximated as a set of uniform regions: The technique will assign well-defined members to homogenous regions in order to achieve image segmentation. The Adaptive fuzzy c-means (AFcM) is a guide to cluster image data. A second stage coding is applied using entropy coding to remove the whole image entropy redundancy. In the decompression phase, the reverse process is applied in which the decoded image suffers from missing details due to the coarse segmentation. For this reason, we suggest the application of total variation (TV) regularization, such as the Rudin-Osher-Fatemi (ROF) model, to enhance the quality of the coded image. Our experimental results had shown that ROF may increase the PSNR and hence offer better quality for a set of benchmark grayscale images.

WITHDRAWN: Multi-classifiers and deep cnns for implementing image block truncation coding in e-learning platform

Abstract Handling the image database with minimal storage complexity, minimal computational complexity and optimal quality is a significant task. To obtain these solutions, many image processing techniques are evolved. In the domain, image compression and decompression are more needed at any cost for effectively handling the complex image databases. Now days, E-Learning resources are widely used around the internet based knowledge sharing environments. In the E-Learning environment, multiple types of data resources are managed. Particularly, organizing the images is more crucial task where multiple qualities of images are appeared inside the E-Learning network databases. This problem expects solutions from effective image compression techniques. Block Truncation Coding (BTC) and Absolute Moment BTC (AMBTC) are the techniques provide useful and easy implementations of E-Learning based image compression platform. At the same time, they are limited to image dissimilarity rate. To maintain the quality of images in both compression and decompression phases, multilevel image analysis models and training phases are required. In this regard, this proposed system develops a Dual Layered Deep Classification and Truncation (DLDCT) technique. DLDCT comprises the baseline benefits of BTC, multi-layered Support Vector Machine (SVM) units and Deep Layered Convolutional Neural Network (DLCNN) for producing classified range of image pixels and compressing the images under controlled circumstances. This proposed DLDCT makes the image compression and decompression with determined observations. This reduces real time errors occur during image reconstruction phases. This proposed system has been implemented and compared with existing works with respect to significant performance parameters.

ECG compression with Douglas-Peucker algorithm and fractal interpolation.

In this paper, we propose a new ECG compression method using the fractal technique. The proposed approaches utilize the fact that ECG signals are a fractal curve. This algorithm consists of three steps: First, the original ECG signals are processed and they are converted into a 2-D array. Second, the Douglas-Peucker algorithm (DP) is used to detect critical points (compression phase). Finally, we used the fractal interpolation and the Iterated Function System (IFS) to generate missing points (decompression phase). The proposed (suggested) methodology is tested for different records selected from PhysioNet Database. The obtained results showed that the proposed method has various compression ratios and converges to a high value. The average compression ratios are between 3.19 and 27.58, and also, with a relatively low percentage error (PRD), if we compare it to other methods. Results depict also that the ECG signal can adequately retain its detailed structure when the PSNR exceeds 40 dB.

Computer Simulation Research on Flow Field of SRM High Altitude Simulation Test

The simulation test of passive ejection type high-altitude solid rocket motor (SRM) was simulated by computer. For SRM passive ejector type high-altitude test, the tempering in the process of engine ignition and flameout poses a serious threat to the nozzle of the engine test device and circuit arrangement in the upper compartment. Using the N-S equation and Spalart-Allmaras model: numerical simulation on the flow structure of engine pressurize, decompression and stratochamber air phase in the testing process, and flow field of the diffuser and the cabin altitude simulation, analyzing the flow field structure of high-altitude experiment stages. The results showed the rough coincidence between the simulation curve and the measured data, with slight difference at the initial stage of air supply, the measured data and the simulation data reach the overall high degree of coincidence. During the process of building a compression and decompression, the adiabatic measures should be taken to prevent high temperature gas from damaging the engine, especially the nozzle and the head ring, in addition, the reasonable design of the nozzle contour surface can control gas separation tempering, reducing the influence caused by tempering. Stability of the flow field in the high altitude chamber of the pressure will not affect the engine.

Experience in the use of dynamic interspinous fixation in the treatment of lumbar spine stenosis

The results of surgical treatment of lumbar stenosis using the dynamic intercostal fixator Coflex in the period from September 2016 to February 2019 were analyzed in 36 patients, 25 of them with monosegmental stenosis, 11 with two levels. Caudogenic intermittent claudication was observed in 27 patients. Dynamic interspinous fixation was performed on38 vertebral-motor segments of the lumbar. Assessment of the quality of life and the intensity of pain in the back and leg before and after the operation, as well as the outcome of the operation in the distant period after the operation, was carried out by validated scales and questionnaires. There were no intraoperative complications. In the distant period after surgery, the results of control functional spondylography of the lumbar revealed a direct dependence of the mobility of the operated vertebral-motor segment on the value of the disk height index. In all observations, a decrease in the mobility of the operated level was noted, which indicated the high-quality functioning of the interspinous implant. An increase in the height of the intervertebral foramen additionally provided indirect decompression of the spinal nerve in all cases. Syndrome of caudogenic intermittent claudication by the time of discharge regressed in all cases. For the period of observation of cases of development of postoperative instability and restenosis at the operated level was not noted. Satisfactory outcomes were obtained in 33 (91,7%), and unsatisfactory outcomes in 3 (8,3%) cases. Unsatisfactory outcomes in two cases were due to chronic pain in the lower back due to symptomatic stenosis of the spinal canal at an adjacent level, and in one observation, severe pain in the right leg due to the formation of sequestered herniated discs at an adjacent level. In general, interspinous dynamic stabilization has proven itself in the treatment of spinal stenosis of the lumbar spine, as the completion of the operation after the decompression phase.