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Epidemiological and clinical studies show that the magnitude and scope of cervical disease are on the rise, along with the world's rising aging population. From a biomechanical perspective, the cervical spine presents a wide inter-individual variability, where its motion patterns and load sharing strongly depend on the anatomy. This study aimed to first develop and validate a geometrically patient-specific model of the lower cervical spine for clinical applications, and secondly to use the model to investigate the spinal biomechanics associated with typical cervical disorders. Based on measurements of 30 parameters from X-ray radiographs, the 3D geometry of the vertebrae and intervertebral discs (IVDs) were developed, and detailed finite element models (FEMs) of the lower ligamentous cervical spine for 6 subjects were constructed and simulated. The models were then used for the investigation of different grades of IVD alteration. The multi directional range of motion (ROM) results were in alignment with the in-vitro and in-Silico studies confirming the validity of the model. Severe disc alteration (Grade 3) presented a significant decrease in the ROM and intradiscal pressure (flexion, extension, and axial rotation) on the C5-C6 and slightly increase on the adjacent levels. Maximum stress in Annulus Fibrosus (AF) and facet joint forces increased for Grade 3 for both altered and adjacent levels. The novel validated geometrically-personalized FEM presented in this study potentially offers the clinical community a valuable quantitative tool for the noninvasive analyses of the biomechanical alterations associated with cervical spine disease towards improved surgical planning and enhanced clinical outcomes.

Acute respiratory distress syndrome (ARDS) was first identified in 1967, as a syndrome associated with heterogeneous lung collapse and a very high mortality. It has been shown that maintaining homogeneous ventilation using mechanical ventilation can improve survival. Using our recent understanding that dynamic alveolar ventilation is viscoelastic in nature, we suggest that a superior technique to open and stabilize the lung would be to extend the time at inspiration, to recruit alveoli with each breath, and to set a very short expiratory time to prevent alveolar collapse. This has led us to develop a novel Time Controlled Adaptive (TCAV) protocol that uses the duration at inspiration and expiration to open and stabilize the lung.

Boron Neutron Capture Therapy (BNCT) beam design needs a special methodology to satisfy the recommended beam parameters required for the proper delivery of treatment doses. In this work, a new design method for a multi-layered spectrum shifter is proposed in order to improve the design process of epithermal BNCT beams for research reactors. The design method is based on two concepts: stepwise spectrum shifting and separation of the design process into two design stages, namely the material selection and the thickness determination. The method has been applied to two case studies using two different sources: a Watt fission neutron spectrum and neutron-gamma spectra of a typical MTR-type reactor radial beam. The different beam components have been designed with a special focus on the spectrum shifter. Java-based Nuclear Information Software (JANIS) has been used for cross sections computations needed for the selection of the spectrum shifter materials. Monte Carlo N–Particle code “MCNP5” has been used for the beam design. To validate the proposed spectrum shifter design method, comparisons have been done between the proposed spectrum shifter and the known patented material “FLUENTAL™” for both cases. The results of comparisons confirm that the proposed design outperforms the “FLUENTAL™” material. The proposed method proved to be time-saving, simple and efficient. Above all, it is based on a more systematic approach rather than the commonly used approaches. Thus, this method can be applied for other epithermal beams as well as other BNCT facilities such as accelerator-based BNCT facilities.

A new molecularly imprinted polymer (MIP) chitosan-TiO2 nanocomposite (CTNC) was prepared for the selective and quantitative removal of Rose Bengal dye from industrial wastewater. The physicochemical features of the prepared CTNC-MIP nanoparticles were thoroughly investigated. The prepared MIP nanoparticles exhibited high surface area (95.38 m2/g) with relatively uniform mesoporous channels that allowed an exceptional uptake of the dye (qm = 79.365 mg/g) and reflected the high selectivity of the prepared MIP compared to pure chitosan. The dye uptake was investigated using Freundlich, Langmuir, Dubinin Radushkevich and Temkin models. The kinetics of removal was explored by pseudo-first, pseudo second order, Elovich and Weber-Morris models. The Experimental data fitted well into pseudo-second order model, and much well with the Langmuir isotherm confirming the formation of monolayer of dye molecules. The enthalpy of adsorption was (62.279 kJ mol−1) showing strong interaction of MIP with the dye. The prepared MIP exhibited a good recyclability and stability.

This study presents a neutronic and thermal–hydraulic estimation to convert a Multi-Application Small Light Water Reactor (MASLWR) with UO2 core to the UO2 + ThO2 core or ThO2 with the minimum possible modifications in the geometry and main parameters of MASLWR core. The thorium considered in this work was already enriched in 233U. MCNPX 2.7.0 (Monte Carlo code) has been used to calculate neutronic parameters such as effective multiplication coefficient (Keff), the nuclear fuel evolution during the burn-up, and the power peaking factor (Pmax/Pav) in the radial direction of the MASLWR different cores. RELAP5 code also has been applied to calculate thermal–hydraulic parameters for fuel rod hot channel, such as the surface heat flux, the coolant channel temperature. The centerline temperature of the fuel was calculated axially and radially, as well as the departure from nucleate boiling (DNB) ratio. The results show that the utilization of thorium (enriched with 233U) fuel improves the overall performance characteristics of the MASLWR. Less or no burnable poisons may be used (especially at the beginning of the reactor cycle); longer reactor cycle and higher fuel burn-up can be achieved, and most attractive feature is its resistance to nuclear proliferation. Also, thermal–hydraulic analysis of fuel rods displayed that the ThO2 fuel rod has a lower axial centerline temperature than UO2, and the DNBR value is about 5.2 for both fuel types and occurred at 0.6 of the fuel height from the inlet side.

Stress triggered concurrent microbial/parasitic infections are prevalent in earthen pond based farmed Nile tilapia Oreochromis niloticus. In the current study, a total of thirty five O. niloticus were collected from a commercial fish farm with a history of severe mortalities at Port Said, Egypt. Nile tilapia samples were subjected to bacteriological, parasitological and pathological examinations. Twenty one Enterococcus fecalis and 15 Streptococcus agalactiae isolates were presumptively identified utilizing the semi-automated API 20 Strept test kit. The identities of the retrieved bacteria were confirmed by the sequencing of 16 S rRNA gene. Moribund O. niloticus were found to be heavily infected by one or both of Centrocestus formosanus encysted metacercariae (EMC) and/or Myxobolus tilapiae spores presenting a unique form of synergistic and/or symbiotic relationship. The identities of both parasites were confirmed through morphological and molecular characterization. Variable circulatory, degenerative, necrotic and proliferative changes were also noticed in hematopoietic organs. Interestingly, multiple myxobolus spores and EMC were noticed in some histological sections. It was obvious that the current concurrent bacterial and parasitic infections are triggered by the deleterious effects of some stressing environmental conditions. The unfavorable climatic conditions (high temperature and high relative humidity) recorded at the surge of mortalities are probable predisposing stress factors.

A gamma-ray system for detecting and measuring the interfaces between different fluids inside oil separators is proposed. Coupling the gamma-ray system with a displacer technique expedites the measurements process as the displacer defines the region for scanning. Monte Carlo calculations were carried out to calculate the sensitivity of the gamma-ray system. The simulation was carried out using Am-241 and Ba-133 gamma-ray sources. At low gamma-ray energy (~35 keV) of Ba-133 source, the system is very sensitive to the fluid composition and density. The concept was tested experimentally using three different fluids: water, engine oil and kerosene which simulate different three phases in an oil separator with a detection system of Ba-133 source and NaI detector. The experiment showed that the system can detect the fluids-interface with high accuracy in short detection time.

Thorium-plutonium mixture is proposed as alternative nuclear reactor fuel to incinerate the increasing stockpile plutonium. However, this fuel will produce an amount of uranium with about 90% 233U at applicable discharge burnups (60GWD/MTU). This research focuses on proposing an optimum non proliferative thorium fuel, by adding a small amount of 238U to reduce the attractiveness of the resultant uranium. Three types of additive which contain 238U were used: 4.98% enriched, natural and depleted uranium. We found that introducing uranium to the fresh thorium-plutonium fuel reduces its performance even if the uranium was enriched up to 5%. While uranium admixtures reduce the quality of the reprocessed uranium, it also increases the quality of the plutonium. However, this increase is very low compared to the reduced quality of uranium. We also found that using uranium as admixture for thorium-plutonium mixed fuel increases the critical mass of the extracted uranium by a factor of two when using only 1% admixture of uranium. The higher the percentage of uranium admixture the higher the critical mass of the reprocessed one.

The aim of this work is to design fast neutron irradiation channels for topaz irradiation at Egypt Second Research Reactor (ETRR-2) by shielding the aluminum boxes, used for topaz irradiation, with B 4 C (boron carbide) or manufacturing the irradiation boxes from aluminum contains boron. This in turn suppresses the thermal neutrons inside the box resulting in reduction of the residual radioactivity in topaz which decreases the worker exposure and release time. Simulation of the fast irradiation channels using the code: MCNPX showed that the thermal neutron component can be suppressed to less than one-tenth. ETRR-2 has many irradiation positions. The fast neutron flux distributions along the irradiation positions and the required irradiation times were calculated. The limiting conditions for safe operation of movable experiments are considered in the selection of the irradiation positions. That is the change in reactor reactivity due to the B-10 shield is below the reactivity limit for safe irradiation experiments. Heat generated during irradiation in topaz and in the material that contains boron was considered, as well. Experimentally, the worker exposure has been reduced to less than one-tenth and a decrease of 12 months in the release time of the irradiated topaz has been achieved. Also adequate cooling of the shielded box during irradiation has been demonstrated.

Seasonal variability is one of the most powerful components in multiple scale variations of plankton communities. A comparison of the seasonal blooms of Noctiluca scintillans in individual basins is combined with a statistical analysis of the relationships between this species and environmental forcing factors. Seasonal patterns of Noctiluca scintillans abundance throughout the Bay of Biscay, the North Sea, the Black Sea, the Sea of Azov, the Sea of Marmara, the Adriatic Sea, the Arabian Sea, Bay of Bengal, the eastern Australian shelf and the Japanese shelf pointed to the persistence of unimodal and bimodal algal blooms, of which unimodal are most common. In general, the duration of the monsoon-induced blooms exceeds that of the temperate regions. A Principal Component Analysis of blooms and environmental characteristics over regions indicated maximal magnitudes of Noctiluca blooms occurring at a medium kinetic energy of mesoscale eddies (from 0.06 to 0.12 m2 s−2), medium-to-high total concentration of nutrients (from 3 to 30 μ m ol), and high wind stress (from 0.04 to 0.07 N m−2).

This research is focused on using Thorium-Plutonium MOX fuel in the inner fuel pins of the CANDU fuel bundles for plutonium incineration and reduction of uranium demand and to reduce coolant void reactivity. The delayed neutron fraction and the power distribution amongst the fuel elements of the fuel bundle have been considered as main safety parameters. The 700 MWe Advanced CANDU Reactor (ACR-700) was selected as a case study. The inner eight UO 2 fuel pins of the ACR-700 fuel bundle are replaced by Thorium-Plutonium MOX fuel pins in the proposed design with 3% reactor grade PuO 2 . This amount represents 23.4 w/o of the fuel in the bundle. The outer two fuel rings (35 pins) enrichment is reduced from 2.1 w/o U-235 to 2 w/o U-235. The simulation using MCNP6 showed that about 27% reduction of uranium demand can be achieved. The proposed fuel bundle eliminate the use of burnable poisons in the central pin that was used for negative coolant void reactivity and more reduction in the coolant void reactivity was achieved (about 3.5 mk less than the reference fuel bundle). The power distribution throughout the fuel bundle is more flat in the proposed fuel bundle. Use of this fuel bundle reduces the delayed neutron fraction from 540 pcm in the reference case to 480 pcm in the proposed case.

The weighted average simulation technique is one of the newest techniques that showed promising capabilities in solving structural reliability problems. In this paper, a modification to the weighted average simulation method is proposed, which allows the computation of the reliability with a small number of performance function evaluations. In addition, an approach for conducting reliability-based design optimization problems by introducing an additional improvement to the weighted average simulation method is proposed. This improvement significantly reduces the number of performance function evaluations needed in the process without sacrificing the accuracy of the results. It was found that the proposed approach can obtain the same results as the original weighted average simulation method with only a fraction of the computational cost required.

Objective MRI is regarded as the study of choice in the diagnosis of lumbar spinal stenosis. In some cases, the supine MRI leads to a misdiagnosis in the extent of lumbar spinal stenosis. Dynamic myelography can detect lumbar spinal stenosis in these cases of where the MRI may not be as sensitive. To compare the sensitivities of dynamic radiographic myelography and supine MRI in lumbar canal stenosis (LCS) patients and to determine whether dynamic radiographic myelography is a valuable diagnostic exam in the work-up of lumbar canal stenosis. Patients & methods Over two years, the imaging data of 100 consecutive patients who were suspected of having LCS were prospectively analyzed. All lumbar intervertebral segments were evaluated in each patient on sagittal MR T2-weighted images and lateral plane images by myelography using a semi-quantitative scoring system. The differences in scores for 5 motion segments under 3 conditions (supine MRI, upright sitting myelography and standing myelography with extension) were analyzed statistically. Results Of 100 patients with 500 analyzed intervertebral segments, 23 patients with inconclusive supine MRI results had LCS in standing myelography with extension. Compared with upright sitting myelography and supine MRI, standing myelography with extension yielded the highest score for every segment from L1/2 to L5/S1. Compared with the upright sitting myelography position, 61 more patients received a diagnosis of lumbar stenosis in the standing myelography with extension position, and 121 more stenotic segments were diagnosed. Compared with the supine MRI position, standing myelography with extension detected 64 more stenotic patients and 137 more stenotic segments. Conclusio n Based on a large patient sample, dynamic myelography is a valuable diagnostic tool in detecting lumbar spinal stenosis. Patients with lumbar spinal stenosis may have inconclusive supine MRI in 23% of cases being misdiagnosed as normal. This missed rate of LCS patients with unclear supine MRI results can be avoided with dynamic myelography. The combination of supine MRI and dynamic myelography is critical in the evaluation of LCS, especially if multisegmental findings are detected.

In a previous work, a new design was proposed for the Pressurized Water Reactor (PWR) fuel assembly for direct use of the PWR spent fuel without processing. The proposed assembly has four zircaloy-4 tubes contains a number of 61-element CANDU fuel bundles (8 bundles per tube) stacked end to end. The space between the tubes contains 44 lower enriched UO 2 fuel rods and 12 guide tubes. In this paper, this assembly is used to build a single batch loading 36-month PWR and the spent CANDU bundles are recycled in the on power refueling CANDU reactors. The Advanced PWR (APWR) is considered as a reference design. The average enrichment in the core is 4.76%w U-235. IFBA and Gd 2 O 3 as burnable poisons are used for controlling the excess reactivity and to flatten the power distribution. The calculations using MCNPX showed that the PWR will discharge the fuel with average burnup of 31.8 MWd/kgU after 1000 effective full power days. Assuming a 95 days plant outage, 36 calendar months can be achieved with a capacity factor of 91.3%. Good power distribution in the core is obtained during the cycle and the required critical boron concentration is less than 1750 ppm. Recycling of the discharged CANDU fuel bundles that represents 85% of the fuel in the assembly, in CANDU-6 or in 700 MWe Advanced CANDU Reactor (ACR-700), an additional burnup of about 31 or 26 MWd/kgU burnup can be achieved, respectively. Averaging the fuel burnup on the all fuel in the PWR assembly, 58 or 54 MWd/kgU burnup of the fuel can be achieved, respectively. Comparing this fuel cycle strategy with that of the advanced pressurized water reactors such as AP-1000 and EPR, we find that almost the same burnup can be achieved with longer core cycle: 36 months versus 18 months for these reactors. Recycling these fuel bundles in CANDU-6 reactors requires minimizing the lattice pitch to 22 cm. In order to keep the coolant void reactivity of the ACR-700 slightly negative, the calandria tube should be increased from 7.8 cm to 8.2 cm to decrease the moderator to fuel volume ratio.

Highlights • Bovine enterovirus (BEV) was isolated from diarrheic calves in Egypt. • Sequencing revealed of BEV/Egypt/2014//KM667941 to have 7417 nucleotides (nt). • The organization of nt was typical of the BEV genome including 822 nt in 5′NTR, 6498 nt in ORF, and 97 nt in 3′NTR. • Phylogenetic analysis revealed clustering of BEV/Egypt/2014/KM667941 with BEV-F. • A specific RT-PCR for BEV was developed to detect this pathogen in cattle., Enteroviruses belong to the Picornaviridae family and infect a wide range of mammals including cattle. Bovine enterovirus (BEV) has recently been reclassified into E and F serotypes. BEV was first isolated in Egypt in 1966 although it has been known in other countries since the 1950s. In this study, BEV-F2 was isolated from calves with severe diarrhea and the isolated viruses were subjected to molecular characterization. Illumina sequencing of one of the isolates revealed the presence of a complete BEV-F genome sequence. The phylogenetic analysis revealed nucleotide substitutions along the genome in comparison with other known strains of BEV-F (HQ663846, AY508697 and DQ092795). Two primer sets were designed from the 3D and 5′NTR regions and used for the examination of the remaining isolates, which were confirmed to be of the BEV-F2 serotype. The availability of the complete genome sequence of this virus adds to the sequence database of the members of Picornaviridae and should be useful in future molecular studies of BEV.

Trauma, hemorrhagic shock, or sepsis can incite systemic inflammatory response syndrome, which can result in early acute lung injury (EALI). As EALI advances, improperly set mechanical ventilation (MV) can amplify early injury into a secondary ventilator-induced lung injury that invariably develops into overt ARDS. Once established, ARDS is refractory to most therapeutic strategies, which have not been able to lower ARDS mortality below the current unacceptably high 40%. Low tidal volume ventilation is one of the few treatments shown to have a moderate positive impact on ARDS survival, presumably by reducing ventilator-induced lung injury. Thus, there is a compelling case to be made that the focus of ARDS management should switch from treatment once this syndrome has become established to the application of preventative measures while patients are still in the EALI stage. Indeed, studies have shown that ARDS incidence is markedly reduced when conventional MV is applied preemptively using a combination of low tidal volume and positive end-expiratory pressure in both patients in the ICU and in surgical patients at high risk for developing ARDS. Furthermore, there is evidence from animal models and high-risk trauma patients that superior prevention of ARDS can be achieved using preemptive airway pressure release ventilation with a very brief duration of pressure release. Preventing rather than treating ARDS may be the way forward in dealing with this recalcitrant condition and would represent a paradigm shift in the way that MV is currently practiced.

Distributed data stores are critical to the success of applications in cloud. Massive volumes of user data are stored and processed with the support of underlying distributed data stores. With large amounts of data stored remotely in the cloud, security becomes a major concern. Authentication and access control are provided by cloud storage providers. But even with proper authentication and access control policies, storage systems are still vulnerable to attackers who have direct access to storage devices such as disks. Encryption makes it computational difficult to retrieve the original data even when the attackers have the access to the disks. However, there are many challenges in designing an encrypted distributed data store that is highly secure and cost-aware. In this paper, we show that security flexibility and cost efficiency can be achieved at the same time. We present Carp, a cost- aware relaxed protocol for encrypted data stores. Carp is a heuristic solution instead of an optimal one. The key idea is to reduce additional encryption operations for frequently accessed data. It is achieved by allowing data objects stay unencrypted for a short time period after the data are accessed. Reducing encryption operations eventually means reducing the computational cost and power consumption in the data store. Unlike conventional encrypted file systems which store data encryption keys on disks, we present a hybrid design of key generation and caching. Data encryption keys are generated for individual objects or a group of them using cryptographic hashing. We develop a prototype data store and conduct experiments. The experimental results show that Carp can reduce up to 20% encryption operations with high-level security.

The article by Liu et al. is a welcome contribution to the literature in which authors evaluate the biomechanical changes of adjacent segments of an instrumented fusion in the spine. It extends our analysis of the importance of realignment in the cervical spine. To date, a considerable amount of clinical and experimental data suggest that fixation of a spinal segment has the potential to provoke compensatory movements in the adjacent segments, thus changing the local biomechanics and, with that, changing the intradiscal forces that may result in faster disc and motion segment

In this paper we proposed a new design for the PWR fuel assembly for direct use of the PWR spent fuel without processing. The PWR spent fuel will be transferred directly (after a certain cooling time) to CANDU reactors which preferably built in the same site to avoid the problem of transportations. The proposed assembly has four zircaloy-4 tubes contains a number of CANDU fuel bundles (7 or 8 bundles per tube) stacked end to end. Each tube has the same inner diameter of that of CANDU pressure tube. The spaces between the tubes contain low enriched UO 2 fuel rods and guide tubes. MCNPX code is used for the simulation and calculation of the burnup of the proposed assembly. The bundles after the discharge from the PWR with their materials inventories are burned in a CANDU cell after a certain decay time. The results were compared with reference results and the impact of this new design on the uranium utilization improvement and on the proliferation resistance of plutonium is discussed. The effect of this new design on the power peaking, moderator temperature coefficient of reactivity and CANDU coolant void reactivity are discussed as well.

Intervertebral disc degeneration has been implicated in the etiology of low back pain; however, the current surgical strategies for treating symptomatic disc disease are limited. A variety of materials have been developed to replace disc components, including the nucleus pulposus (NP), the annulus fibrosus (AF) and their combination into disc-like engineered constructs. We have previously shown that layers of electrospun poly(ε-caprolactone) scaffold, mimicking the hierarchical organization of the native AF, can achieve functional parity with native tissue. Likewise, we have combined these structures with cell-seeded hydrogels (as an NP replacement) to form disc-like angle-ply structures (DAPS). The objective of this study was to develop a model for the evaluation of DAPS in vivo. Through a series of studies, we developed a surgical approach to replace the rat caudal disc with an acellular DAPS and then stabilized the motion segment via external fixation. We then optimized cell infiltration into DAPS by including sacrificial poly(ethylene oxide) layers interspersed throughout the angle-ply structure. Our findings illustrate that DAPS are stable in the caudal spine, are infiltrated by cells from the peri-implant space and that infiltration is expedited by providing additional routes for cell migration. These findings establish a new in vivo platform in which to evaluate and optimize the design of functional disc replacements.

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Let R and S be rings with identity, M be a unitary ( R , S ) -bimodule, and T = R M 0 S be the upper triangular matrix ring determined by R , S and M. Let E ij be the standard matrix unit. In this paper we show that every biderivation of T is decomposed into the sum of three biderivations D , Ψ and Δ , where D ( E 11 , E 11 ) = 0 , Ψ is an extremal biderivation and Δ is a special kind of biderivation. Using this characterization, we determine the structure of biderivations of the ring T n ( R ) ( n ⩾ 2 ) of all n × n upper triangular matrices over R, and show that in the special case when R is a noncommutative prime ring, every biderivation of T n ( R ) is inner. This extends some results of Benkovic (2009) [1] .

Okasha, N. M., & Frangopol, D. M. (2011). Computational platform for the integrated life-cycle management of highway bridges. Engineering structures, 33(7), 2145-2153., Throughout their service life, highway bridges are subject to progressive deterioration in performance; an issue that may render the use of these facilities unsafe at some point in time. Over the last few decades, there has been successful research towards developing procedures for establishing the various vital elements required in the life-cycle management of civil infrastructure. It is noted, however, that frameworks for integrating these elements together are lacking. The objective of this paper is to present an integrated framework for the life-cycle management of highway bridges in the form of a detailed computational platform. The elements integrated into the framework include the advanced assessment of life-cycle performance, analysis of system and component performance interaction, advanced maintenance optimization, and updating the life-cycle performance by information obtained from structural health monitoring and controlled testing.

The lifetime reliability of existing structures may be quantified by lifetime functions. Redundancy is an additional type of structural performance indicator that is defined as a measure of warning available prior to system collapse. Lifetime functions provide a basis on which lifetime redundancy can be evaluated and its quantification can be formulated. The objective of this paper is to present a novel approach for the evaluation of the lifetime redundancy of structural systems. Measures of lifetime redundancy based on lifetime functions are investigated. The effects of maintenance on lifetime functions and redundancy are also presented. Furthermore, the lifetime redundancy is incorporated in a maintenance optimization algorithm. This optimization algorithm is illustrated on an existing highway bridge.