2,305 research outputs found

    Computer assisted navigation in spine surgery

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    INTRODUCTION: Computer aided navigation is an important tool which has the capability to enhance surgical accuracy, while reducing negative outcomes. However, it is a relatively new technology and has not yet been accepted as the standard of care in all settings. OBJECTIVES: The objective of the present study is to present the development and current state of technologies in computer aided navigation in Orthopedic Spine Surgery, specifically in navigated placement of pedicle screws, to examine the clinical need for navigation, it's effect on surgical accuracy and clinical outcome and to determine whether the benefits justify the costs, and make recommendations for future use and enhancements. CONCLUSION: Computer aided navigation in pedicle screw placement enhances accuracy, reduces the probability of negative outcomes, reduces the exposure of the patient and staff to radiation, reduces operative time, and provides cost-savings. Future investigations may potentially enhance this effect further with the use of innovative augmented reality type displays

    Microchips and their significance in isolation of circulating tumor cells and monitoring of cancers

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    In micro-fluid systems, fluids are injected into extremely narrow polymer channels in small amounts such as micro-, nano-, or pico-liter scales. These channels themselves are embedded on tiny chips. Various specialized structures in the chips including pumps, valves, and channels allow the chips to accept different types of fluids to be entered the channel and along with flowing through the channels, exert their effects in the framework of different reactions. The chips are generally crystal, silicon, or elastomer in texture. These highly organized structures are equipped with discharging channels through which products as well as wastes of the reactions are secreted out. A particular advantage regarding the use of fluids in micro-scales over macro-scales lies in the fact that these fluids are much better processed in the chips when they applied as micro-scales. When the laboratory is miniaturized as a microchip and solutions are injected on a micro-scale, this combination makes a specialized construction referred to as "lab-on-chip". Taken together, micro-fluids are among the novel technologies which further than declining the costs; enhancing the test repeatability, sensitivity, accuracy, and speed; are emerged as widespread technology in laboratory diagnosis. They can be utilized for monitoring a wide spectrum of biological disorders including different types of cancers. When these microchips are used for cancer monitoring, circulatory tumor cells play a fundamental role

    On homogeneous CR manifolds and their CR algebras

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    In this paper we show some results on homogeneous CR manifolds, proved by introducing their associated CR algebras. In particular, we give different notions of nondegeneracy (generalizing the usual notion for the Levi form) which correspond to geometrical properties for the corresponding manifolds. We also give distinguished equivariant CR fibrations for homogeneous CR manifolds. In the second part of the paper we apply these results to minimal orbits for the action of a real form of a semisimple Lie group \^G on a flag manifold \^G/Q.Comment: 14 pages. AMS-LaTeX v2: minor revisio

    Educational Research Issue in English Language Teaching and Learning

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    English language is considered as the most leading language globally. Previous studies affirmed that English language teaching and learning (ELT) is the most challenging area. A huge number of researches and publications are being published in this area concerning various aspects. Therefore, this study aims to presents a meta-analysis of previously done studies seek to investigate the various aspects in English language teaching and learning. The study is based on qualitative research approach as entire data has been collected from existing journals and research databases. A number of 8 articles have been gathered which have been published from 2012 to 2017. The findings of this meta-analysis provides the value to researcher and academic practitioners as well

    Experimental maps of DNA structure at nucleotide resolution distinguish intrinsic from protein-induced DNA deformations

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    Recognition of DNA by proteins depends on DNA sequence and structure. Often unanswered is whether the structure of naked DNA persists in a protein–DNA complex, or whether protein binding changes DNA shape. While X-ray structures of protein–DNA complexes are numerous, the structure of naked cognate DNA is seldom available experimentally. We present here an experimental and computational analysis pipeline that uses hydroxyl radical cleavage to map, at single-nucleotide resolution, DNA minor groove width, a recognition feature widely exploited by proteins. For 11 protein–DNA complexes, we compared experimental maps of naked DNA minor groove width with minor groove width measured from X-ray co-crystal structures. Seven sites had similar minor groove widths as naked DNA and when bound to protein. For four sites, part of the DNA in the complex had the same structure as naked DNA, and part changed structure upon protein binding. We compared the experimental map with minor groove patterns of DNA predicted by two computational approaches, DNAshape and ORChID2, and found good but not perfect concordance with both. This experimental approach will be useful in mapping structures of DNA sequences for which high-resolution structural data are unavailable. This approach allows probing of protein family-dependent readout mechanisms.National Institutes of Health [R01GM106056 to R.R., T.D.T.; U54CA121852 in part to T.D.T.]; Boston University Undergraduate Research Opportunities Program [Faculty Matching Grants to D.O. and Y.J.]; USC Graduate School [Research Enhancement Fellowship and Manning Endowed Fellowship to T.P.C.]. R.R. is an Alfred P. Sloan Research Fellow. Funding for open access charge: Boston University. (R01GM106056 - National Institutes of Health; U54CA121852 - National Institutes of Health; Boston University Undergraduate Research Opportunities Program; USC Graduate School; Boston University)https://academic.oup.com/nar/article/46/5/2636/4829691?searchresult=1https://academic.oup.com/nar/article/46/5/2636/4829691?searchresult=1Published versio

    Granulomatous gastritis: a diagnostic dilemma?

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    Granulomatous inflammation of the gastrointestinal tract is an uncommon entity, an aetiopathogenic diagnosis can be reached only by combining the morphological examination with clinical and laboratory investigations. We report two cases of granulomatous gastritis: a 27-year-old woman presenting with weight loss and a 55-year-old woman presenting with epigastric pain and vomiting. Upper oesophagastroduodenoscopy in these cases showed antral hyperaemia and histopathology showed non-caseating gastric granulomatous inflammation. Both the cases were extensively worked-up for possible tuberculosis (TB) as the Patients lived in an endemic area, before starting steroids for the possibility of Crohn\u27s disease (CD). The first Patient improved but the second Patient had a flare of underlying undiagnosed TB. Granulomatous gastritis present a diagnostic challenge for treating physicians because of similar clinical, laboratory and endoscopical features between CD and intestinal TB

    Takayasu’s arteritis in pregnancy

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    We had the opportunity to manage a pregnant lady who presented for the first time at 34 weeks of amenorrhea with absent pulses in upper limbs on examination. She underwent Magnetic Resonance Angiography to confirm the diagnosis of Takayasu’s arteritis. Luckily she did not have complications of Takayasu’s such as hypertension, cardiac failure, neurological symptoms, visual disturbances. She proceeded to have a normal vaginal delivery after aggressive management which included a multidisciplinary team involving obstetrician, cardiologist, physician and rheumatologist

    Macrocalcification in thyroid nodule

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    Background: The thyroid is one of the largest endocrine organs. The prevalence of palpable thyroid nodules increases with age and is 4-7% in a middle-aged population. Objective of present study was to understand if thyroid malignancy is associated with macrocalcification.Methods: 34 cases were with thyroid nodules were evaluated initially with sonography and then with FNAC, the results of which were given on the basis of Bethesda system.Results: On USG, 23 (67.6%) nodules had macrocalcifications, 5 (14.7%) had microcalcifications and 6 (17.6%) had both micro as well as macrocalcifications. Cytology of 23 nodules with macrocalcification were non-diagnostic in 8.7%, benign 73.9%, suspicious for malignancy in 8.7 % and malignant in 8.7%. Only 2 lesions with macrocalcification and 1 with both macro and microcalcification came out to be non-diagnostic. 17 lesions with macrocalification were diagnosed as benign, 2 as suspicious for malignancy and 2 as malignant. While 3 lesions with microcalcification were diagnosed as malignant on FNAC and 2 as benign.Conclusions: Macrocalcification is not a good indicator for malignancy

    Energy Management of Dynamic Wireless Power Transfer Systems for Electric Vehicle Applications

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    Wireless power transfer is a method of transferring electric power from a transmitter to a receiver without requiring any physical connection between the two. Dynamic Wireless Power Transfer (DWPT) entails having the transmitters buried under the roadway and the receiver unit being installed on the Electric Vehicle (EV). In this method, EVs are charged while driving over the transmitters as they receive bursts of electric energy at the time of significant alignment between transmitters and receivers. Compared to the stationary charging method which involves parking the EV for long hours for a full charge, the dynamic charging method (i.e., DWPT) offers convenience as the vehicle gets charged while driving. It also facilitates extended driving range of EVs. Despite offering these advantages, DWPT causes a few significant issues. DWPT charging results in a transient power profile both at grid side and EV side, which not only hampers grid-side regulation but also affects EV-battery longevity. To address these two issues, both grid-side and EV-side energy management are needed to be employed to protect the grid and the vehicle from sudden exposure to harmful power transients. In this dissertation, the grid-side and EV-side energy management methods have been investigated. Firstly, a detection system to safely detect the vehicle on charging lane is proposed. This detection system is used to facilitate safe and efficient operation of DWPT chargers on EV roadways. Secondly, A novel DWPT system is proposed, which reduces the grid-side power transients with minimal additional hardware requirements. Finally, an EV-side energy management system is proposed which reduces the exposure of EV batteries to pulsating DPWT-power, thereby helping batteries to last longer
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