3,867 research outputs found
Use of cylindrical titanium mesh and locking plates in anterior cervical fusion
Journal ArticleAfter performing anterior cervical corpectomy or discectomy for cervical spondolytic myelopathy or radiculopathy, iliac crest bone graft and fibular auto- or allograft is often used to achieve arthrodesis in the cervical spine. The purpose of this study was to evaluate the use of a cylindrical titanium mesh and locking plate system as an alternative technique in achieving anterior cervical fusion and maintaining lordosis. Hospital records and radiographs of 38 patients who underwent anterior cervical discectomies (28 patients) or corpectomies (10 patients) from 1995 to 1997 were reviewed retrospectively. All patients had undergone arthrodesis in which autograft and a cylindrical titanium mesh and anterior locking plate fixation were used after discectomy or corpectomy. There were 20 men and 18 women (mean age 46.1 years; range 34-72 years). Presenting symptoms included radiculopathy (61%), myelopathy (37%), and neck pain (2%). Preoperative and postoperative radiographs were studied, and data were obtained on the following: overall lordosis or kyphosis of the cervical spine, segmental lordosis or kyphosis at each surgically treated level, and evidence of fusion. In all of the patients in whom lordosis was present preoperatively, lordosis was maintained during the follow-up period. The overall fusion rate was 100%. The average change in overall lordosis or kyphosis related to the fixation devices was 1.2° (range 1-5°); the average segmental change was 2.3° (range 0-5°); and the mean follow up was 16 months (range 12-36 months). Anterior cervical fusion with cylindrical titanium mesh and cervical locking plate system is an effective method of achieving arthrodesis and maintaining alignment in the cervical spine. The construct may provide additional load-sharing function, and it avoids the use of cadaveric bone or the need for harvesting tricortical iliac crest autograft
Irving S. Cooper (1922-1985): a pioneer in functional neurosurgery
Journal ArticleIrving S. Cooper (1922-1985), the son of a salesman, worked his way through high school, college, and medical school to become one of the pioneers in functional neurosurgery. He developed several novel techniques for the surgical management of Parkinson's disease and other crippling movement disorders. A keen interest in the physiology of movement disorders was kindled by his doctoral research and continued during his neurosurgical training. He began to apply this knowledge to surgical practice in 1952 when he began his faculty career as Assistant Professor of Surgery at New York University. At the time, surgical treatment of parkinsonian tremor focused on various techniques used to interrupt the pyramidal tract. During a subtemporal approach for a cerebral pedunculotomy, he inadvertently injured and, subsequently, was forced to occlude the anterior choroidal artery. Much to Cooper's surprise, following emergence from anesthesia the patient's tremor and rigidity were abolished without any residual hemiparesis. This serendipitous observation, together with Meyer's earlier work on the role of the basal ganglia in motor control, helped focus surgical efforts on targets within the basal ganglia and, subsequently, within the thalamus to alleviate the movement disorders associated with Parkinson's disease. While at New York University, Cooper developed chemopallidectomy and, later at St. Barnabas Hospital in the Bronx (1954-1977), he used cryothalamectomy as a surgical technique for primary control of tremor in patients with Parkinson's disease. Cooper authored many original papers on surgical techniques and several textbooks on the lives of patients afflicted with Parkinson's disease and other crippling movement disorders. Although considered controversial, this fascinating and complex neurosurgeon made significant contributions to this field
Posterolateral approach for decompression with anterior and posterior fusion: a less invasive surgical technique for stabilization of the thoracic spine
Journal ArticleThe goals of surgery in unstable thoracic fractures or tumors involving the thoracic spine are neural decompression, correction of deformity, and stabilization. Several different approaches can be used to achieve these goals. The anterior, combined anterior and posterior, and more recently thoracoscopic approaches are well described in the literature and are extremely effective in achieving the goals mentioned. However, they do carry with them significant morbidity and mortality rates in patients who are elderly, who have associated medical problems, or for whom there are contraindications to thoracic surgery. The authors believe the posterolateral approach is a viable alternative that is reasonably well tolerated in this select patient population. One can achieve circumferential neural decompression as well as anterior and posterior arthrodesis through a single incision. Most neurosurgeons are familiar with the anatomical landmarks and technical steps in the posterolateral approach, and the authors believe it is a less invasive method that can be especially useful and should not be overlooked in this subgroup of patients
New analysis method of the halo phenomenon in finite many-fermion systems. First applications to medium-mass atomic nuclei
A new analysis method to investigate halos in finite many-fermion systems is
designed, as existing characterization methods are proven to be
incomplete/inaccurate. A decomposition of the internal wave-function of the
{-body} system in terms of overlap functions allows a model-independent
analysis of medium-range and asymptotic properties of the internal one-body
density. The existence of a spatially decorrelated region in the density
profile is related to the existence of three typical energy scales in the
excitation spectrum of the {-body} system. A series of model-independent
measures, taking the internal density as the only input, are introduced. The
new measures allow a quantification of the potential halo in terms of the
average number of fermions participating to it and of its impact on the system
extension. Those new "halo factors" are validated through simulations and
applied to results obtained through energy density functional calculations of
medium-mass nuclei. Performing spherical Hartree-Fock-Bogoliubov calculations
with state-of-the-art Skyrme plus pairing functionals, a collective halo is
predicted in drip-line Cr isotopes, whereas no such effect is seen in Sn
isotopes.Comment: 27 Pages, 29 Figures. Accepted for publication in Phys. Rev. C
back-to-back with second part (arXiv:0711.1275
Traditional Rural Wetlands in Haryana State of India Are Currently Confronting Multicornered Threats Leading to Extinction Sooner Than Later
The most serious threat to traditional rural ponds in Haryana is associated with transformed societal behavioural patterns, ethics, values and life style, amongst several others. The siltation of ponds with adjoining areas, soil coming in with rain water is a very serious cause of stratification of rural ponds. Also contracting of village community land for sun drying of cow dung cakes inspires villagers to overload periphery of each pond with cow dung turning the premises into grave-yard of dung. This dung is the major source of polluting pond water into blackish water with high load of organic matter. Moreover, it leads to over excessive eutrophication. Building of major highways and connectivity roads have resulted into compartmentalization and degradation of village ponds. Inhabitation of peripheral village ponds boundaries by lower section of society for dwelling purposes is more threat to wetlands. The indifferent inclination of villagers towards silted ponds drenched in bad odour and blackish sludge is the story of 80% of the cases. The total blockage of run-off rainy water towards the natural age old rural ponds due to obstruction by way of human inhabitation has resulted into desertification of shallow water sheet in 90% of the cases. The oblivion of harvesting dried silt in summer for brick making has spelled doom for the ponds turning them into flat ground through successive decades and so on. The water quality in all ponds was overshooting the decaying stage due to the continuous mixing of cow dung drenched rainy water. Over excessive USAge of ponds for bathing of cattle, dumping of cow dung and rotten vegetables waste has turned ponds into live sinks of dirt, garbage and rural dairy wastes. Majority of village ponds are now out of existence or in deep black sludge laden or converted into Fish-Farming wetlands. The present studies have indicated that Winter migratory birds like Greylag Goose Anser anser, Bar-headed Goose Anser indicus, Mallard Anas platyrhynchos, Gadwall Anas strepera, Northern Shoveller Anas clypeata, Northern Pintail Anas acuta, Garganey Anas querquedula, Common Teal Anas crecca, Common Pochard Aythya ferina, Tufted Pochard Aythya fuligula, Common Coot Fulica atra, Little Ringed Plover Charadrius dubius, Kentish Plover Charadrius alexandrines, Spotted Redshank Tringa erythropus, Common Redshank Tringa tetanus, Marsh Sandpiper Tringa stagnatilis, Wood Sandpiper Tringa glareola and Pied Avocet Recurivirostra avosetta arrive in the extremely dilapidated rural ponds in Haryana from far off places including Russia, Siberia, China, and Caspian region, east Asia each winter season without any break. As such the extinction of ponds in Haryana directly threatens global avian biodiversity
Halo phenomenon in finite many-fermion systems. Atom-positron complexes and large-scale study of atomic nuclei
The analysis method proposed in Ref. \cite{rotival07a} is applied to
characterize halo properties in finite many-fermion systems. First, the
versatility of the method is highlighted by applying it to light and
medium-mass nuclei as well as to atom-positron and ion-positronium complexes.
Second, the dependence of nuclear halo properties on the characteristics of the
energy density functional used in self-consistent Hartree-Fock-Bogoliubov
calculations is studied. It is found that (a) the low-density behavior of the
pairing functional and the regularization/renormalization scheme must be chosen
coherently and with care to provide meaningful predictions, (b) the impact of
pairing correlations on halo properties is significant and is the result of two
competing effects, (c) the detailed characteristics of the pairing functional
has however only little importance, (d) halo properties depend significantly on
any ingredient of the energy density functional that influences the location of
single-particle levels; i.e. the effective mass, the tensor terms and the
saturation density of nuclear matter. The latter dependencies give insights to
how experimental data on medium-mass drip-line nuclei can be used in the
distant future to constrain some characteristics of the nuclear energy density
functional. Last but not least, large scale predictions of halos among all
spherical even-even nuclei are performed using specific sets of particle-hole
and particle-particle energy functionals. It is shown that halos in the ground
state of medium-mass nuclei will only be found at the very limit of neutron
stability and for a limited number of elements.Comment: 24 Pages, 32 Figures. Accepted for publication in Phys. Rev. C
back-to back with first part (nucl-th/0702050
Description of Avian Bio-Diversity of Damdamma Jheel in Gurgaon District in Haryana, India
Damdamma Jheel is a wetland of impressive potentials of harboring rich avian bio-diversity in the accompaniment of enhanced habitat reconstruction and improvement. It is located in the National Capital Region, nearby Sohana town in Gurgaon district in Haryana merely 45 Kms from Dhaula Kuan in New Delhi. At present, compared to Sultanpur National Park, it is confronting neglect. Considering its positive features of terrain, water sheet, it has the qualities of being a rich habitat for birds of all hues including the winter migratory birds. The present studies focus attention on its avian biodiversity as well as its own degraded form and structure. In all, 128 species of birds belonging to 15 orders and 41 families could be enlisted. Order Passeriformes is the predominant one having 54 species, followed by Charadriiformes (14 Species) and Ciconiiformes (12 Species). The prominent winter migratory birds observed from Damdamma Jheel include Asian Openbill Stork Anastomus oscitans, Eurasian Spoonbill Platalea leucorodia, Northern Shoveller Anas clypeata, Northern Pintail Anas acuta, Common Teal Anas crecca, Common Pochard Aythya ferina, Gadwall Anas strepera, Spot-billed Duck Anas poecilorhyncha, Spotted Redshank Tringa erythropus, Common Redshank Tringa tetanus, Common Greenshank Tringa nebularia, Kentish Plover Charadrius alexandrinus, White-tailed Lapwing Vanellus leucurus, Marsh Sandpiper Tringa stagnatilis, Wood Sandpiper Tringa glareola, Common Sandpiper Actitis hypoleucos, White Wagtail Motacilla alba and Yellow Wagtail Motacilla flava. The lake is suffering from water scarcity considering its capacity and potential to have more water. The periphery towards east is plagued by the growth of peats. The very fact that in October 2012, a large group of Openbill Stork (Nearly 70-80) has already arrived at Damdamma Lake since September-2012 indicates that it is the largest HARBOUR of Open-bill Stork in Haryana. Also, Eurasian Spoonbills were seen in a group 10-12, again the largest in Haryana. It is argued in this paper, that Damdamma is the pride lake of Haryana and prime harbor for uncommon winter migratory birds like Open-bill Stork and Eurasian Spoonbill must be the prime place for habitat reconstruction by Ministry of Environment and Forest, Govt. of India in conjunction with Govt. of Haryana with the active contributions by WWF (India) to add to the might vastness of this lake an element of grace and glory so as to conserve the winter migratory birds during their sojourn in India. In addition, it will be one nodal point to include Sultanpur National Park, Badkhal Lake, Bhindawas and Keoladeo National Park as an eco-tourism rectangle with provision for night halt
Pentoxifylline in anaemia resistant to erythropoietin (PEAR) study A double blind placebo controlled randomised trial
PhDBackground Hyporesponsiveness to erythropoiesis-stimulating agents (ESA) and its association with adverse cardiovascular outcomes remains a considerable problem in patients with end-stage renal disease (ESRD) undergoing haemodialysis. Pentoxifylline has been shown to have some beneficial effect on ESA Hyporesponsiveness by reducing inflammation in ESRD patients. Methods We conducted a single centre, double-blind, placebo-controlled randomised trial to study the effect of Pentoxifylline on Erythropoietin stimulating agent (ESA) requirement of stable haemodialysis patients. Inclusion criteria were equivalent ESA dose of greater than or equal to 6000 International Units (I.U) per week or ESA resistance index greater than or equal to 6.5 I.U /kg/wk/Hb (g/dl) and stable Hb between 9 to 12 g/dl. The primary study endpoint was ESA requirement relative to Haemoglobin (Hb) level at the end of study period of 6 months. Secondary endpoints included safety analysis, Hb values, ESA dose and cardiovascular imaging biomarkers such as vascular PET CT and cardiac MRI scan. Cytokine profile was also analysed during the study. Results A total of 69 patients underwent randomisation. At the end of the study period, there was no statistically significant (p value= 0.26) difference in ESA /Hb ratio between pentoxifylline and placebo group (Mean (SD) 3.98 mcg/gm/dl (3.09) versus 4.91 mcg/gm/dl (3.49) respectively). The secondary outcomes did not show any statistically significant change between pentoxifylline and placebo group. There were no concerns regarding the safety of pentoxifylline in haemodialysis patients. The cytokine profile showed a reduction in inflammatory cytokines titres and rise in anti-inflammatory cytokines in the entoxifylline group analysed as slopes of cytokine variability longitudinally. Conclusions Pentoxifylline did not improve the ESA requirement in ESA hyporesponsive, stable haemodialysis patients over six months period. There was no statistically significant change in cardiovascular imaging biomarkers between Pentoxifylline and placebo group. Cytokine profile showed a favourable response to Pentoxifylline therapy.National Institute of Health Researc
Electron transport properties of sub-3-nm diameter copper nanowires
Density functional theory and density functional tight-binding are applied to
model electron transport in copper nanowires of approximately 1 nm and 3 nm
diameters with varying crystal orientation and surface termination. The copper
nanowires studied are found to be metallic irrespective of diameter, crystal
orientation and/or surface termination. Electron transmission is highly
dependent on crystal orientation and surface termination. Nanowires oriented
along the [110] crystallographic axis consistently exhibit the highest electron
transmission while surface oxidized nanowires show significantly reduced
electron transmission compared to unterminated nanowires. Transmission per unit
area is calculated in each case, for a given crystal orientation we find that
this value decreases with diameter for unterminated nanowires but is largely
unaffected by diameter in surface oxidized nanowires for the size regime
considered. Transmission pathway plots show that transmission is larger at the
surface of unterminated nanowires than inside the nanowire and that
transmission at the nanowire surface is significantly reduced by surface
oxidation. Finally, we present a simple model which explains the transport per
unit area dependence on diameter based on transmission pathways results
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