15,699 research outputs found
A simple and effective method for directing the sagittal placement of thoracic pedicle screws without intraoperative imaging
Concurrent Session 5A: Adolescent Idiopathic Scoliosis & Complications. Paper no. 94postprintThe 17th International Meeting on Advanced Spine Techniques (IMAST 2010), Toronto, Canada, 21-24 July 2010
„Kitalált történetek”. ,A látogató’ és az ,Útvesztõ’
Andrographolide (Andro) has emerged recently as a potential and effective anticancer agent with induction of apoptosis in some cancer cell lines while induction of G2/M arrest with weak apoptosis in others. Few studies have proved that Andro is also effective in combination therapy. The flavonoid Taxifolin (Taxi) has showed anti-oxidant and antiproliferative effects against different cancer cells. Therefore, the present study investigated the cytotoxic effects of Andro alone or in combination with Taxi on HeLa cells. The combination of Andro with Taxi was synergistic at all tested concentrations and combination ratios. Andro alone induced caspase-dependent apoptosis which was enhanced by the combination with Taxi and attenuated partly by using Z-Vad-Fmk. Andro induced a protective reactive oxygen species (ROS)-dependent autophagy which was attenuated by Taxi. The activation of p53 was involved in Andro-induced autophagy where the use of Taxi or pifithrin-α (PFT-α) decreased it while the activation of JNK was involved in the cell death of HeLa cells but not in the induction of autophagy. The mitochondrial outer-membrane permeabilization (MOMP) plays an important role in Andro-induced cell death in HeLa cells. Andro alone increased the MOMP which was further increased in the case of combination. This led to the increase in AIF and cytochrome c release from mitochondria which consequently increased caspase-dependent and independent cell death. In conclusion, Andro induced a protective autophagy in HeLa cells which was reduced by Taxi and the cell death was increased by increasing the MOMP and subsequently the
'Spring-back' closure associated with open-door cervical laminoplasty
BACKGROUND CONTEXT: Spring-back complication after open-door laminoplasty as described by Hirabayashi is a well-known risk, but its definition, incidence, and associated neurologic outcome remain unclear. OBJECTIVE: To investigate the incidence and the neurologic consequence of spring-back closure after open-door laminoplasty. STUDY DESIGN: A retrospective radiographic and clinical review. OUTCOME MEASURES: Lateral cervical spine X-rays were evaluated. Anteroposterior diameters (APD) of the vertebral canal of C3-C7 were measured. Spring-back was defined as loss of APD on follow-up in comparison to immediate postoperative canal expansion. The loss of the end-on lamina silhouette with consequent reappearance of the lateral profile of the spinous processes was also assessed to verify the presence of spring-back. Spring-back closure was classified based on whether the collapse was total or partial, and whether all the operated levels or only a subset had collapsed (ie, complete vs. partial closure, segmental closure vs. total-construct closure). Neurologic status was documented using the Japanese Orthopaedic Association (JOA) score. METHODS: Thirty consecutive patients who underwent open-door laminoplasty from 1995 to 2005 at a single institution with a minimum follow-up of 2 years were assessed. They were all operated on using the classic Hirabayashi technique. Radiographic outcomes were assessed independently by two individuals. RESULTS: Sixteen men and 14 women with an average follow-up of 5 years (range, 2-12 years) were included. Of these patients, 24 had cervical spondylotic myelopathy and six had ossification of the posterior longitudinal ligament. Spring-back closure was found in three patients (10%) and 7 of 117 laminae (6%) within 6 months of the operation, which was further confirmed by computed tomography and magnetic resonance imaging. All spring-back closures were partial segmental closures. Gender and age were not significant factors related to spring back (p>.05). The mean JOA score on follow-up was 12.5, with a recovery rate of 40%. All patients with spring back and available JOA data exhibited postoperative neurologic deterioration. Of the three patients with spring back, two patients underwent revision surgery, whereas one declined. CONCLUSIONS: Spring-back closure occurred in 10% of our patients at or before 6 months after surgery. The incidence of spring-back by level (ie, 117 laminae) was 6%, mainly occurring at the lower cervical spine. All spring-back closures were partial segmental closures, most commonly involving C5 and C6. Postoperative neurologic deficit was associated with spring-back closure; therefore, surgeons should adopt preemptive surgical measures to prevent the occurrence of such a complication.postprin
A survey of network lifetime maximization techniques in wireless sensor networks
Emerging technologies, such as the Internet of things, smart applications, smart grids and machine-to-machine networks stimulate the deployment of autonomous, selfconfiguring, large-scale wireless sensor networks (WSNs). Efficient energy utilization is crucially important in order to maintain a fully operational network for the longest period of time possible. Therefore, network lifetime (NL) maximization techniques have attracted a lot of research attention owing to their importance in terms of extending the flawless operation of battery-constrained WSNs. In this paper, we review the recent developments in WSNs, including their applications, design constraints and lifetime estimation models. Commencing with the portrayal of rich variety definitions of NL design objective used for WSNs, the family of NL maximization techniques is introduced and some design guidelines with examples are provided to show the potential improvements of the different design criteri
Cross-layer network lifetime optimization considering transmit and signal processing power in WSNs
Maintaining high energy efficiency is essential for increasing the lifetime of wireless sensor networks (WSNs), where the battery of the sensor nodes cannot be routinely replaced. Nevertheless, the energy budget of the WSN strictly relies on the communication parameters, where the choice of both the transmit power as well as of the modulation and coding schemes (MCSs) plays a significant role in maximizing the network lifetime (NL). In this paper, we optimize the NL of WNSs by analysing the impact of the physical layer parameters as well as of the signal processing power (SPP) P_sp on the NL. We characterize the underlying trade-offs between the NL and bit error ratio (BER) performance for a predetermined set of target signal-to-interference-plus-noise ratio (SINR) values and for different MCSs using periodic transmit-time slot (TS) scheduling in interference-limited WSNs. For a per-link target BER requirement (PLBR) of 10^?3, our results demonstrate that a ’continuous-time’ NL in the range of 0.58?4.99 years is achieved depending on the MCSs, channel configurations, and SPP
Distinguishing Various Models of the 125 GeV Boson in Vector Boson Fusion
The hint of a new particle around 125 GeV at the LHC through the decay modes
of diphoton and a number of others may point to quite a number of
possibilities. While at the LHC the dominant production mechanism for the Higgs
boson of the standard model and some other extensions is via the gluon fusion
process, the alternative vector boson fusion is more sensitive to electroweak
symmetry breaking through the gauge-Higgs couplings and therefore can be used
to probe for models beyond the standard model. In this work, using the well
known dijet-tagging technique to single out the vector boson fusion mechanism,
we investigate its capability to discriminate a number of models that have been
suggested to give an enhanced inclusive diphoton production rate, including the
standard model Higgs boson, fermiophobic Higgs boson, Randall-Sundrum radion,
inert-Higgs-doublet model, two-Higgs-doublet model, and the MSSM. The rates in
vector-boson fusion can give more information of the underlying models to help
distinguishing among the models.Comment: 31 pages, 3 figures; in this version some wordings are change
The treatment experiences of people living with ileostomies: an interpretative phenomenological analysis
AIMS: To explore treatment and healthcare experiences of people living with ileostomies, so nurses can build on best practice whilst caring for these patients.
Background Ileostomies, in which the small intestine is re-directed out of a stoma in the abdominal wall so waste is collected using a bag, are used to treat conditions including Inflammatory Bowel Disease. Existing research suggests that although life with a stoma can be challenging, ileostomy patients are largely supported by multi-disciplinary teams. However, more research is needed to understand the nuances of these relationships and experiences of treatment, with a view to improving clinical care.
DESIGN: Participants took part in semi-structured interviews consisting of open ended questions about their experiences of life with an ileostomy and their treatments and time in hospital. Points of interest were followed up. Data were collected between July and December of 2014.
METHODS: The qualitative method Interpretative Phenomenological Analysis was used to analyse interviews with 21 people living with ileostomies.
FINDINGS: We present findings from two clinical themes: Issues around treatment and Relationships with multi-disciplinary teams. Surgical complications were common, and several participants reported concerns about addiction to painkillers. Varying attitudes were found around reversal surgery. Many reported experiencing distressing, dehumanising care, whilst some felt supported by excellent healthcare providers.
CONCLUSION: People living with ileostomies have a very mixed experience of multi-disciplinary teams and treatments, and much could be done to support them more fully. For example, more information about ileostomies could be given to patients and more training given to nurses around stomas
High frequency diffraction of an electromagnetic plane wave by an imperfectly conducting rectangular cylinder
Copyright @ 2011 IEEEWe shall consider the the problem of determining the scattered far wave field produced when a plane E-polarized wave is incident on an imperfectly conducting rectangular cylinder. By using the the uniform asymptotic solution for the problem of the diffraction of a plane wave by a right-angled impedance wedge, in conjunction with Keller's method, the a high frequency far field solution to the problem is given
Higgs boson enhancement effects on squark-pair production at the LHC
We study the Higgs boson effects on third-generation squark-pair production
in proton-proton collision at the CERN Large Hadron Collider (LHC), including
\Stop \Stop^*, \Stop\Sbot^*, and \Sbot \Sbot^*. We found that substantial
enhancement can be obtained through s-channel exchanges of Higgs bosons at
large , at which the enhancement mainly comes from , , and initial states. We compute the complete set of electroweak
(EW) contributions to all production channels. This completes previous
computations in the literature. We found that the EW contributions can be
significant and can reach up to 25% in more general scenarios and at the
resonance of the heavy Higgs boson. The size of Higgs enhancement is comparable
or even higher than the PDF uncertainties and so must be included in any
reliable analysis. A full analytical computation of all the EW contributions is
presented.Comment: 23 pages, 7 figures, 1 tabl
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