The MRI finding of the nerve root sedimentation sign: Its clinical validity and operative relativity for patients with lumbar spinal stenosis

AbstractBackgroundLumbar spinal stenosis (LSS) is increasingly being recognised as a cause of disabling low back and lower extremities pain in adult population. Advanced spinal imaging thought as confirmation tool for the diagnosis and as preoperative tool to delineate the extent and precise location of the pathology. Nerve roots normally sediment, due to gravity, to the dorsal part of the dural sac, which was known as negative sedimentation sign. If there is MRI finding of nerve roots in the ventral part of the dural sac the sedimentation sign is positive.ObjectivesTo evaluate the presence of the MRI finding of positive sedimentation sign in patients clinically suspected to have lumbar spinal stenosis and to follow up operated cases to identify the absence of the radiological signs in the operated cases.Material and methods70 patients clinically suspected to have lumbar spinal stenosis evaluated by MRI lumbosacral spine in supine position. A panel of two radiologists reviewed radiological data. MRI features were agreed by both radiologists in 48 patients. Out of these 48 patients; 25 were operated upon for central decompressive laminectomy, partial medial facetectomy and foraminotomy with instrumented fusion and fixation if indicated. Visual analogue score (VAS) collectively preoperative and postoperative was compared and the walking distance postoperative was reported and follow up MRI studies were done one year after the operation.ResultsOperated patients’ mean age was 58.2years; nineteen patients were operated upon for simple decompressive laminectomy for the affected levels. Walking distance preoperative range 100–700metres, improved postoperative to be 1474.0±601.1. VAS for pain preoperative was 9.28±0.84, improved at 12month follow up to be 0.84±0.62. Postoperative MRI done to evaluate the cross sectional area (CSA) became more than 80mm2 in the absence of the sedimentation sign and was negative in 22 cases.ConclusionThe MRI finding of positive sedimentation sign is a good positive sign to rule in lumbar spinal stenosis with high specificity and sensitivity; negative sedimentation sign can be used in postoperative follow up of decompression patients

Effect of Tire Lug Height, Forward Speed and Cast Iron Ballast on Tractor Performance

The study was conducted at El Rahad Agricultural Scheme (Block 8( Sudan, during the period Feb.-May 1996 where the soil is a heavy cracking clay. The objective of the study was to improve the performance of the tractor when worn tires were used. The performance of the tractor, wheel slippage, fuel consumption and field capacity of the tractor were measured. Three levels of tire lug height were used, namely, 35 mm (new tire), 20 mm (medium worm tire) and zero mm (fully worn tire). Four levels of cast iron ballast were used, namely, zero, 63, 126 and 252 kg were distributed between rear tires. Moreover, three levels of tractor forward speed (5.6, 6.9 and 10.6 km/hr) were employed. The results indicated that there was a significant improvement in tractor performance when using worn tires through the use of cast iron ballast on the rear wheels. It was found that tires with zero mm lug height and 252 kg cast iron ballast decreased tractor wheel slippage and fuel consumption by34% and 18%, respectively, and increased tractor field capacity by 16.2 % Moreover, when tires with 20 mm lug height and 252 kg cast iron ballast were used, the slippage and fuel consumption were decreased by 41.7 % and 18.2%, respectively, and tractor field capacity was increased by 14.5%. The tractor with tires lug height of 35 mm and 252 kg cast iron ballast, decreased slippage and fuel consumption by 22% and 11.5%, respectively, and increased tractor field capacity by 13.5%

Sectional variable frequency and voltage regulation control strategy for energy saving in beam pumping motor systems

Despite the fact that the energy losses in the beam pumping motor systems (BPMS) utilized in oil fields represent a monumental challenge industrially, very few studies discussed the feasibility and applicability of a universal energy saving technology for such industry. This study proposes a sectional control strategy integrating variable frequency (VF) with voltage regulation (VR) based on the mechanical load characteristics of the BPMS. Main merits of the proposed strategy are as follows: 1) controlling horse-head acceleration through VF, and indirectly weakening the inertia torque of polished rod load, thereby reducing the power consumption during the up-stroke; and 2) based on monitoring load conditions in real time, auto-tracking VR is adopted to optimize the online efficiency of the system. The proposed strategy utilized the adaptive fuzzy logic control to alternate between VF and VR modes. The proposed energy saving strategy was applied to a CYJ10 BPMS driven via a 37-kW induction motor in simulation and experimental environments. Results revealed that the effectiveness of the proposed strategy to improve the load balance effects through better utilization of the counterbalance during the heavy-loading conditions in up-stroke. Furthermore, the energy consumption is reduced via the auto-tracking of VR under light-loading conditions during the down-stroke. Moreover, the energy saving ratio is more than 10% under different dynamic liquid levels and counter weights. The effectiveness of the proposed strategy is verified through comparing the calculated results with the measured data for a standard oil rig, and the generality is verified as well

Promising Deep Semantic Nuclei Segmentation Models for Multi-Institutional Histopathology Images of Different Organs

Nuclei segmentation in whole-slide imaging (WSI) plays a crucial role in the field of computational pathology. It is a fundamental task for different applications, such as cancer cell type classification, cancer grading, and cancer subtype classification. However, existing nuclei segmentation methods face many challenges, such as color variation in histopathological images, the overlapping and clumped nuclei, and the ambiguous boundary between different cell nuclei, that limit their performance. In this paper, we present promising deep semantic nuclei segmentation models for multi-institutional WSI images (i.e., collected from different scanners) of different organs. Specifically, we study the performance of pertinent deep learning-based models with nuclei segmentation in WSI images of different stains and various organs. We also propose a feasible deep learning nuclei segmentation model formed by combining robust deep learning architectures. A comprehensive comparative study with existing software and related methods in terms of different evaluation metrics and the number of parameters of each model, emphasizes the efficacy of the proposed nuclei segmentation models

New Methodology for Prestressing Fiber Composites

Abstract The development of composite materials is characterized by the improvement of their mechanical properties (stiffness and strength) which have widened their application for structural fields like automobile, aerospace, and naval industries. The mechanical properties of composite materials can be upgraded during the manufacturing process by applying an appropriate load on the fibers and curing the corresponding matrix at certain temperature. For that purpose a machine was designed and built to exert load and heat on a composite of carbon fiber mat or glass fiber mat and matrix. The result is a rig agreed with horizontal tensiometer that can be called a prestress machine. This machine holds a certain tension on the fibers while the matrix is being cured. The main parts of the prestress machine are the mold, pulling crosshead, oven and sensors. This paper presents the steps of constructing and using this machine. Experimental investigations were carried out to determine the complete set of stiffness characteristics E ij , G ij , ν ij and strength characteristics σ i,n , ε i,n . The outcome results show that this machine can produce prestressed composite materials with much better mechanical properties comparing to those properties of the non-prestressed composite materials

An Insight into Sybil Attacks – A Bibliometric Assessment

Sybil attack poses a significant security concern in both centralized and distributed network environments, wherein malicious adversary sabotage the network by impersonating itself as several nodes, called Sybil nodes. A Sybil attacker creates different identities for a single physical device to deceive other benign nodes, as well as uses these fake identities to hide from the detection process, thereby introducing a lack of accountability in the network. In this paper, we have thoroughly discussed the Sybil attack including its types, attack mechanisms, mitigation techniques that are in use today for the detection and prevention of such attacks. Subsequently, we have discussed the impact of the Sybil attack in various application domains and performed a bibliometric assessment in the top four scholarly databases. This will help the research community to quantitatively analyze the recent trends to determine the future research direction for the detection and prevention of such attacks

Role of Head Nurses in Managing the Safety of High Alert Medications in Critical Care Units

high-alert medication is a medication that bears a heightened risk of causing significant patient harm when used in error .Head nurses are responsible for managing and improving the safety of high alert medications within the critical care unit.  Nurses receive directions and cooperation with their head nurses to achieve this target. A total of 236 nurses were willing to participate in the descriptive cross-sectional study. The first aim of this study was to develop a new questionnaire to describe the role of head nurses towards the nurses during practices of the safety of high alert medications. A secondary aim was to identify the factors influencing these roles. The key results of this study were the establishment of the questionnaire to describe the head nurse role in managing the safety of high alert medications as a reliable and valid tool that can be used to assess nurses’ perception in this respect. Head nurses role in this study was generally mild. Evaluation role was lesser than management, patient care and supervision and development roles. These results can be attributed to a combination of factors, some related to an organizational system and the other to managerial factors. Keywords: head nurses, role, high alert, medication

Determining the optimal range of coupling coefficient to suppress decline in WPTs efficiency due to increased resistance with temperature rise

The continuous operation of the wireless power transfer system (WPTS) under high-frequency switching activity might cause a temperature rise in various system\u27s components. That temperature rise might increase the resistance of the primary and secondary coils, which will lead to a significant decline in the system\u27s efficiency. To address this problem at the design stage, we investigate the optimal range of the coupling coefficient that suppresses the efficiency drop due to the increasing resistance of the WPTS components. The proposed optimal range of the coupling coefficient can also ensure the output power requirements of the WPTS. Using four different WPTSs, the determination method for the optimal range of coupling coefficients under different system operational frequencies was developed and implemented. A 3-kW resonant experimental prototype WPTS was designed and built to validate the proposed coupling coefficients experimentally. The experimental results show that the optimized coupling range successfully suppressed the efficiency decline resulting from the increasing resistance caused by temperature rise

Modified technique for sacrospinous-sacrotuberous ligament complex colpopexy in apical prolapse: preliminary results of a pilot randomized study

Background: Apical prolapse is frequently encountered following vaginal hysterectomy either or as a primary finding in patients with pelvic organ prolapse. This pilot comparative study introduces a modified sacrospinous sacrotuberous ligament fixation with biologic mesh augmentation which necessitates no special kits to be performed.Methods: This study was conducted at Department of Obstetrics and gynecology, Ain Shams University, Cairo, Egypt, and Department of Women Health of Bethanien Hospital, Iserlöhn, Germany from March 2018 to May 2020. 40 women with either utero-vaginal or vaginal vault prolapse were randomized to either; group (A): 20 women scheduled for modified sacrospinous-sacrotuberous fixation procedure, or group (B): 20 women scheduled for conventional sacrospinous-sacrotuberous fixation procedure.Results: Improvement of the Pelvic organ prolapse quantification system (POP-Q) stage from the base line pre-operative stage was 1 stage higher in the modified SS/ST-F group compared to the conventional SSF group (3 stage improvement from baseline in SS/ST-F group versus 2 stage improvement only in conventional SSF group).Conclusions: This pilot study provides a modified sacrospinous sacrotuberous ligament colpopexy technique which is easier to be performed and mastered, does not need the use of special devices, provides better improvement of grade of prolapse and less complications compared to the conventional technique.

Evaluation of Cerebral Hemodynamics in Cirrhotic Patients by Transcranial Doppler Ultrasonography and its Relation to Hepatic Encephalopathy

The study aimed at Aim evaluation the cerebral hemodynamics in cirrhotic patients by transcranial Doppler ultrasonography and its relation to hepatic encephalopathy. This study is a prospective study , 50 subjects attended El Hussein university hospital, inpatient and outpatient clinic are classified into three groups, group I(10 subjects as a healthy control),group II (20 subjects with liver cirrhosis without hepatic encephalopathy) and group III(20 subjects with liver cirrhosis with hepatic encephalopathy). All patients included in the study underwent a full history taking,complete physical examination, liver functions tests,blood ammonia level,C.B.C,blood urea and serum creatinine and pelvi-abdominal ultarasonography. Transcranial Doppler done for all patients participated in the study using a 2 MHz transducer. The results showed that as regard Trans cranial Doppler ultrasound parameters, we found a statistical significant difference between the three groups as regard Pulsatility Index (P ˂ 0.001), Breath-Holding Index (P ˂ 0.001) ) , Maximum Flow Velocity(P ˂ 0.001) and Mean (P ˂ 0.001), whereas Pulsatility Index, , Maximum Flow Velocity and Mean are higher in patient with Hepatic Encephalopathy, but Breath-holding index is low, there is no statistical significant difference (P > 0.05) between them as regard Minimum Flow Velocity. Conclusion: Transcranial doppler ultrasonography is easy, rapidly done not invasive method for evaluation of cerebral hemodynamic in cirrhotic patient and predection of hepatic encephalopathy. Keywords: Transcranial doppler, Hepatic encephalopathy, Cirrhosis