276 research outputs found
Sternoclavicular instability - reconstruction of sternoclavicular ligament using semitendinosus autograft
Background: Injury to the sternoclavicular joint is rare with an incidence of 3% of all the injuries around the shoulder girdle. Most of them heal with conservative treatment. Rarely some progress to chronic instability associated with pain.Methods: We present a small series of 4 such cases of chronic symptomatic sternoclavicular joint instability. We performed reconstruction of the sternoclavicular ligament using semitendinosus autograft, with excellent result, with minimum of 15 months follow up.Results: All the patients returned to pre injury level of activity at the end of 6 months. There was significant improvement in the DASH score following surgery. Our results are comparable with that of Castropil et al, who had performed a similar technique. Conclusions: Reconstruction of sternoclavicular ligament using the semitendinosus autograft is a safe, reproducible and functionally good surgical option in patients with chronic sternoclavicular instability
FIXATION, PERMANENCY, AND LEACHING OF COPPER CHROME ARSENATE (CCA) WOOD PRESERVATIVES: AN OVERVIEW OF THEORIES, MECHANISMS, AND IMPLICATIONS
With regards to Copper-Chromium-Arsenic (CCA) wood preservative chemicals, it is now established that fixation level of the CCA elements is a function of wood species, wood quality, CCA formulation, temperature, time, preservative application method, and conditioning techniques. The amount of Cu, Cr and As leached from CCA-treated wood is known to decrease with increases in the level of fixation. The permanence of a chemical preservative in wood is the single most important factor that determines the effectiveness of the preservative system. Depletion mechanisms that affect all types of wood preservatives include leaching, bleeding, blooming, vaporisation, volatilisation, migration, and biodetoxification. Although well understood, the chemical and physical mechanisms involved in the fixation and permanency of CCA elements in wood cell walls, appear to have posed problems not yet resolved. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down
A New Extensible Key Exchange Scheme For Wireless Sensor Networks
A sensor network is confident of a large number of sensor nodes Sensor nodes are small, low-cost, low-power devices that have following performance communicate on short distances sense environmental data perform limited data processing The network usually also contains “sink” node which connects it to the outside world. Advances in technology introduce new application areas for sensor networks. Foreseeable wide deployment of mission critical sensor networks creates concerns on security issues. Security of large scale slowly deployed and infrastructure-less wireless networks of resource limited sensor nodes requires efficient key distribution and management mechanisms. We consider distributed and hierarchical wireless sensor networks where unjust, multicast and broadcast type of communications can take place. We evaluate deterministic, probabilistic and hybrid type of key pre-distribution and dynamic key generation algorithms for distributing combination and network-wise keys
A Hybrid Cryptographic System for Secured Device to Device Communication
It is general fact that even after enormous expansion of wireless communication there are still dead regions that hampers the effective communication. With exponential rise in the smart phones, a new layer of communication has evolved that could address the concerns of dead regions and capacity barriers. D2D is the evolving communication technology which focuses on short distance hops between the public devices to reach the destination. The major drawback of this technology is that most of the devices are public hence trustworthiness of the entire channel needs to be addressed in order to make it a viable solution. In this paper, we introduce a novel hybrid cryptographic approach that could address multiple eavesdroppers’ scenario. This approach incorporates both Huffman coding and Binary coding to enhance the crypto benefits for the information transmitted over D2D channel that consists of several public devices. The dual-crypto nature of the proposed algorithm offers higher efficiency, better security and improved key transmission. Thus, the proposed hybrid cryptographic approach is robust in nature while easy and simple to operate. In addition, the proposed approach could recover the original information without any distortion from the encrypted data making the approach lossless in nature. Further simulation results prove that the proposed offers confidentiality to the transmitted to data while addressing the network capacity crunch
Efficient And Secure Hop-By-Hop Message Authentication And Source Privacy In Wireless Sensor Networks
security to the data is actually provided by an authentication. Authentication involves a process of confirming an identity. In Wireless sensor networks a lot of message authentication schemes have been developed, based on symmetric-key cryptosystems or public-key cryptosystems. Message authentication is one of the most effective way to prevent illegal and tainted messages from being forwarded in wireless sensor networks (WSNs). For this cause, Most of them, however, have the limitations of high computational and communication overhead in addition to lack of scalability and pliability to node compromise attacks. To address these issues, a Polynomial-based scheme was recently introduced. Though, this scheme and its extensions all have the flaw of a built-in Threshold determined by the degree of the polynomial: when the number of messages transmitted is larger than this threshold, the adversary can fully recover the polynomial. In this paper, we suggest a scalable authentication scheme based on Elliptic Curve Cryptography (ECC) with Schnorr Signcryption. While enabling intermediate nodes authentication, our proposed scheme solve the threshold problem. In addition, our scheme can also provide message source privacy. Both theoretical analysis and simulation results demonstrate that our proposed  scheme is efficient than the polynomial-based approach in terms of computational and communication overhead under comparable security levels
Dynamic hip screw technique in the management of trochanteric fracture
Background: Study was conducted to find the results of dynamic hip screw in the management of trochanteric fracture by analyzing the factors which influence post-operative mobility.Methods: Study was conducted in the department of orthopedics, GSL Medical College. Individuals >18 years, both genders who were diagnosed having trochanteric type I and II Boyd and Griffin stable fractures were included in the study. All surgeries were performed under spinal anesthesia, internal fixation with dynamic hip screw and 135o angled blade plate. Injectable third generation cephalosporins were used 24 hours preoperatively, intra- operatively and 5 days post-operatively, and oral antibiotics till suture removal. Patients allowed to sit on bed on 2nd and 3rd day and static quadriceps exercises were started from 2nd day onwards, hip and knee flexion exercises from 6 or 7th day and weight bearing walking form 10th day.Results: The average age was of the participants was 61.53 years, ranged between 41 to 80 years; 65% were female participants and 35% were male patients. In the study, 20 (50%) patients had right side fracture and left sided affection of trochanteric fracture to the remaining 50%. Most of the patients (67.5%) in this study were classified as type II Boyd and Griffin criteria, and 32.5% were type I. The clinical and functional outcome was calculated using the Kyle's criteria; 25% (10) showed excellent response, followed by good (50%), fair (15%) and poor (10%) results.Conclusions: Dynamic hip screw is the operative treatment of choice for stable trochanteric fractures. However, studies on large sample for long time are recommended
Caerulomycin A inhibits Th2 cell activity: a possible role in the management of asthma
We have recently demonstrated that Caerulomycin A induces regulatory T cells differentiation by suppressing Th1 cells activity. The role of regulatory T cells is well established in suppressing the function of Th2 cells. Th2 cells are known to inflict the induction of the activation of asthma. Consequently, in the present study, we monitored the influence of Caerulomycin A in inhibiting the activity of Th2 cells and its impact in recuperating asthma symptoms. Interestingly, we observed that Caerulomycin A significantly suppressed the differentiation of Th2 cells, as evidenced by downregulation in the GATA-3 expression. Further, decline in the levels of IL-4, IL-5 and IL-13 cytokines and IgE was noted in the animals suffering from asthma. Furthermore, we noticed substantial suppression in the inflammatory response and number of eosinophils in the lungs. In essence, this study signifies an important therapeutic role of Caerulomycin A in asthma
Experimental Studies of Resin Systems for Ablative Thermal Protection System
The present work was initiated to finalise resin for the development of thermal protection system (TPS) for the external surface of a polymeric composite rocket motor case made up of Carbon roving and Epoxy resin. The temperature on the outer surface of the composite case increases due to kinetic heating caused by aerodynamic drag and vehicle velocity. These rocket motor casings are functionally required only in the ascent phase of missile trajectory till motor action time and stage separation. Due to which the experienced heat flux is relatively less, and the temperature on the external composite case is in order of 250 °C - 300 °C depending on missile configuration and trajectory, unlike extreme thermal conditions on ablative nozzle liners exposed to rocket motor exhaust. The maximum allowable temperature in the present study for the Carbon-Epoxy case is 100 °C due to degradation in mechanical properties. The thermal protection system on the external surface will function as a heat-insulating layer based on the working mechanism of ablation. The resin of the thermal protection layer has a substantial impact on the manufacturing process and curing aspects, especially compatibility with the pre-cured carbon epoxy case layer. The generation of test results for thermal stability, cure characteristics and Tg for Epoxy resin has also been included in present studies as an additional objective that provides significant inputs for process development. The test results for Epoxy resin is also used as a basis for the finalisation of resin for the thermal protection layer for processing aspects apart from its basic thermal stability characteristics. The ablative thermal protection working mechanism is based on the ablation phenomenon. In the case of ablation, resin plays a vital role due to pyrolysis and other thermal characteristics. In the present experimental studies, the Phenolic resin and Silicone resin are considered as candidate resin materials for ablative thermal protection system based on available literature and in house experience. The main objective of the present studies is to evaluate thermal stability, char yield after final decomposition through DSC and TGA techniques for both resins as these are fundamental characteristics needed for the present specific application. The test results for specific grades (formulation) of phenolic and Silicone resins are generated and compared. In the present work, the experimental studies to evaluate glass transition temperature (Tg), thermal stability, and cure characteristics for Epoxy resin is also carried through DSC. The test results of specific grade Epoxy resin provides a basis to assess thermal margins for resins selected for ablative thermal protection system and inputs for process development and design requirements. The scope of the present studies is aimed to finalise the resin system for external thermal protection of composite rocket motor case based on thermal characteristics test results and other compatibility aspects with the structural layer
Variational Calculations for He Impurities on He Droplets
Variational Monte Carlo method is used to calculate ground state properties
of He droplets, containing 70, 112, 168, 240, 330, and 728 particles. The
resulting particle and kinetic energy densities are used as an input in the
Feynman-Lekner theory for He impurities. The kinetic energy density of
He atoms and the energy of the He surface states are compared with the
results of previous phenomenological calculations.Comment: 12 pages, in revtex 3.0, with 5 .ps figure
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