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Latest Paper:
Appl Opt. 2012 May 1;51 (13):2288-97
22614403
2, 3-butanedione dihydrazone (BDDH) synthesized via chemical route and nonlinear optical parameters, such as nonlinear refractive index (n<sub>2</sub>), nonlinear absorption coefficient (β), third-order nonlinear optical susceptibility (χ<sup>(3)</sup>), second hyperpolarizability (γ), and optical-limiting behavior were investigated by single beam z-scan technique for different concentrations. Synthesized sample were irradiated by a Q-switched, frequency doubled Nd:YAG laser and found that n<sub>2</sub> and β increases linearly with increasing concentration and hence γ decreases linearly. The excited-state absorption cross sections of BDDH were found to be larger than ground-state absorption cross sections, and it leads to reverse saturable absorption (RSA). The experimental results are well in agreement with the theory and also establish BDDH as one of the potential candidate materials for optical limiting at 532 nm.
Department of Clinical Neurosciences and the Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
ABSTRACT: Like insulin, glucagon-like peptide 1 (GLP-1) may have direct trophic actions on the nervous system, but its potential role in supporting diabetic sensory neurons is uncertain. We identified wide expression of GLP-1 receptors on dorsal root ganglia sensory neurons of diabetic and nondiabetic mice. Exendin-4, a GLP-1 agonist, increased neurite outgrowth of adult sensory neurons in vitro. To determine the effects ofexendin-4 in comparison with continuous low- or high-dose insulin in vivo, we evaluated parallel cohorts of type 1 (streptozotocin-induced) and type 2 (db/db) mice of 2 months' diabetes duration with established neuropathy during an additional month of treatment. High-dose insulin alone reversed hyperglycemia in type 1 diabetic mice, partly reversed thermal sensory loss, improved epidermal innervation but failed to reverse electrophysiological abnormalities. Exendin-4 improved both sensory electrophysiology and behavioral sensory loss. Low-dose insulin was ineffective. In type 2 diabetes, hyperglycemia was uncorrected, and neither insulin nor exendin-4 reversed sensory electrophysiology, sensory behavior, or loss of epidermal axons. However, exendin-4 alone improved motor electrophysiology. Receptor for advanced glycosylated end products and nuclear factor-κB neuronal expression were not significantly altered by diabetes or treatment. Taken together, these results suggest that although GLP-1 agonists and insulin alone are insufficient to reverse all features of diabetic neuropathy, in combination, they might benefit some aspects of established diabetic neuropathy.
Institute of Cytology and Preventive Oncology (ICMR), Noida, India.
Alternative strategies are being proposed for early detection of cervical cancer in developing countries. Several investigators have proposed that visual examination of the cervix is an alternative to cervical cytology screening (1-3). Training modules have been developed with success for paramedical staff, mainly nurses, auxiliary midwives and teachers (4-5).
Neurobiol Dis. 2012 May 5;:
22569359
Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary.
OBJECTIVES: To evaluate whether augmenting neuronal protective mechanisms might slow or arrest experimental diabetic peripheral neuropathy (DPN). DPN is one of the most common neurodegenerative disorders and is rising in prevalence. How it targets sensory neurons is uncertain; the disorder is irreversible and untreatable. We explored the intrinsic protective properties of overexpressed human HSP27 on experimental DPN. HSP27 is a small pro-survival heat shock protein that also increases axonal regeneration. METHODS: Experimental diabetes was superimposed on mice overexpressing a human HSP27 transgene and its impact was evaluated on epidermal innervation, behavioural tests of sensation and electrophysiological indices of DPN. RESULTS: Mice that overexpress human HSP27 in their sensory and motor neurons and that were made diabetic for six months by streptozotocin treatment were protected from a range of neuropathic abnormalities, including loss of footpad thermal sensation, mechanical allodynia, loss of epidermal innervation, and slowing of sensory conduction velocity. The protection was selective for sensory neurons in comparison to motor neurons and at six months provided better protection in female than male mice. Markers of RAGE-NFκB activation were attenuated by the transgene. CONCLUSIONS: The findings support the idea that diabetic polyneuropathy involves a unique, sensory-centric neurodegenerative process which can be reduced by overexpressing a single gene, an important starting point for new disease-modifying therapeutic approaches.
B Koteswararao,
A V Mahajan,
F Bert,
P Mendels,
J Chakraborty,
V Singh,
I Dasgupta,
S Rayaprol,
V Siruguri,
A Hoser,
S D Kaushik
Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076, India.
The chain-like system Ba(3)Cu(3)Sc(4)O(12) has potentially interesting magnetic properties due to the presence of Cu(2+) and a structure-suggested low dimensionality. We present magnetization M versus magnetic field H and temperature T, T- and H-dependent heat-capacity C(p),(45)Sc nuclear magnetic resonance (NMR), muon spin rotation (μSR), neutron diffraction measurements and electronic structure calculations for Ba(3)Cu(3)Sc(4)O(12). The onset of magnetic long-range antiferromagnetic (AF) order at T(N) ∼ 16 K is consistently evidenced from the whole gamut of our data. A significant sensitivity of T(N) to the applied magnetic field H (T(N) ∼ 0 K for H = 70 kOe) is also reported. Coupled with a ferromagnetic Curie-Weiss temperature (θ(CW) ∼ 65 K) in the susceptibility (from a 100 to 300 K fit), it is indicative of competing ferromagnetic and antiferromagnetic interactions. These indications are corroborated by our density functional theory based electronic structure calculations, where we find the presence of significant ferromagnetic couplings between some copper ions whereas AF couplings were present between some others. Our experimental data, backed by our theoretical calculations, rule out the one-dimensional magnetic behavior suggested by the structure and the observed long-range order is due to the presence of non-negligible magnetic interactions between adjacent as well as next-nearest chains.
Spine (Phila Pa 1976). 2012 May 4;:
22565384
Angela D Melnyk,
Tian Lin Wen,
Stephen Kingwell,
Jason D Chak,
Vaneet Singh,
Peter A Cripton,
Charles G Fisher,
Marcel F Dvorak,
Thomas R Oxland
1Department of Mechanical Engineering, University of British Columbia 2Department of Orthopaedics, University of British Columbia 3ICORD, Vancouver Coastal Health Research Institute 4Beijing Army General Hospital, Beijing, China 5University of Ottawa Hospital, Ottawa, Ontario, Canada 6Division of Spine, Department of Orthopaedics, University of British Columbia, Vancouver, BC, Canada 7Medtronic Inc., Memphis, Tennessee, USA.
Study Design. A biomechanical human cadaveric study.Objective. To determine the percentage of shear force supported by posterior lumbar spinal devices of varying stiffnesses under anterior shear loading in a degenerative spondylolisthesis model.Summary of Background Data. Clinical studies have demonstrated beneficial results of posterior arthrodesis for the treatment of degenerative spinal conditions with instability. Novel spinal implants are designed to correct and maintain spinal alignment, share load with the spine, and minimize adjacent level stresses. The optimal stiffness of these spinal systems is unknown. To our knowledge, low-stiffness posterior instrumentation has not been tested under an anterior shear force, a highly relevant force to be neutralized in the clinical case of degenerative spondylolisthesis.Methods. The effects of implant stiffness and specimen condition on implant load and intervertebral motion were assessed in a biomechanical study. Fifteen human cadaveric lumbar functional spinal units were tested under a static 300 N axial compression force and a cyclic anterior shear force (5-250 N). Implants (High-Stiffness (HSI): ø5.5 mm Titanium, Medium-Stiffness (MSI): ø6.35 × 7.2 mm Oblong PEEK, and Low-Stiffness (LSI): ø5.5 mm Round PEEK) instrumented with strain gauges were used to calculate loads and were tested in each of three specimen conditions simulating degenerative changes: intact, facet instability and disc instability. Intervertebral motions were measured with a motion capture system.Results. As predicted, implants supported a significantly greater shear force as the specimen was progressively destabilized. Mean implant loads as a percent of the applied shear force in order of increasing specimen destabilization for the HSI were: 43, 67 and 76%, for the MSI were: 32, 56 and 77%, and for the LSI were: 18, 35 and 50%. Anterior translations increased with decreasing implant stiffness and increasing specimen destabilization.Conclusion. Implant shear stiffness significantly affected the load-sharing between the implant and the natural spine in anterior shear ex vivo. Low-stiffness implants transferred significantly greater loads to the spine. This study supports the importance of load-sharing behaviour when designing new implants.
Department of Civil Engineering, Environmental Engineering Laboratory, Indian Institute of Technology Delhi, New Delhi - 110016, India.
This study reports applicability of upflow anaerobic sludge blanket (UASB) process to treat the leachate from a municipal landfill located in Delhi. A laboratory scale reactor was operated at an organic loading rate of 3.00 kg chemical oxygen demand (COD)/m(3) d corresponding to a hydraulic retention time (HRT) of 12 h for over 8 months. The effect of toxicity of leachate, and feed composition on the treatability of leachate was evaluated. Average COD of the leachate, during the study period varied between 8,880 and 66,420 mg/l. Toxicity of the leachate used during a period of 8 months varied from LC50 1.22 to 12.35 for 96 h. The removal efficiency of soluble COD ranged between 91 and 67% for fresh leachate and decreased drastically from 90 to 35% for old leachate having high toxicity. The efficiency varied from 81 to 65%. The reactor performed more efficiently for the treatment of fresh leachate (less toxic, LC50 11.64, 12.35, and 12.15 for 96 h) as compared with old leachate (more toxic, LC50 1.22 for 96 h). Toxicity of the leachate affected its treatment potential by the UASB.
Skinmed. ;10 (2):116-8
22545332
Department of Dermatology, Venereology & Leprology, Gian Sagar Medical College & Hospital, Ram Nagar, Banur, Patiala, India. dr.varindersingh11@gmail.com
A 16-year-old young man presented with intensely itchy erythematous dermatitis on the body for 1 week and vesicular lesions on the palms and soles for 4 to 5 days. Lesions on the palms and soles were accompanied by severe burning and itching. The patient gave a history of sore throat and fever, 1 week prior to the onset of lesions. A general physical examination was normal, and cutaneous examination revealed multiple, well-defined erythematous scaly plaques with collaret scaling on the trunk and extremities (Figure 1). Vesicular lesions were seen on the palms and soles (Figure 2). The differential diagnoses we considered were pityriasis rosea and secondary syphilis. The possibility of dermatophytid, vesicular pityriasis rosea, and pompholyx was limited to the palms and sole lesions. Complete blood cell count was within normal limits. Results from antistreptolysin O titer, potassium hydroxide mount, and venereal disease research laboratory were negative. Skin biopsies were taken from the back and left palm. The biopsy specimen from the back revealed focal spongiosis, lymphocyte exocytosis, vacuolar changes in the basal layer, and perivascular lymphocytic infiltrate in the dermis (Figure 3). The biopsy obtained from the vesicular lesion on the left palm revealed an intraepidermal vesicle with no evidence of acantolytic process (Figure 4). A diagnosis of pityriasis rosea was made and the patient was started on clarithromycin 500 mg once a day for 7 days, along with antihistamines and emollients. The lesions faded dramatically in a very short period, and there was significant involution of almost all of the lesions after 7 days of clarithromycin. During the 6 months of follow-up, no recurrence was observed.
Binod Kumar,
Dibya R Pati,
Madhu Khanna,
Prashant Kumar,
Mradul K Daga,
Varinder Singh,
S Khare,
Sn Gaur
Department of Respiratory Virology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India.
Eur J Clin Nutr. 2012 Apr 18;:
22510791
G Trilok-Kumar,
H Arora,
M Rajput,
H Chellani,
V Singh,
J Raynes,
S Arya,
S Aggarwal,
N Srivastava,
H P S Sachdev,
S Filteau
Department of Biochemistry, Institute of Home Economics, Delhi University, New Delhi, India.
BACKGROUND/OBJECTIVES:Vitamin D deficiency has been associated with impaired resistance to infection, which may be mediated by alterations in cytokine responses. We investigated the effect of vitamin D supplementation to infants on whole blood in-vitro cytokine production and on the inflammatory marker, plasma C-reactive protein (CRP).SUBJECTS/METHODS:Blood samples were taken at 6 months of age from infants participating in the DIVIDS (Delhi Infant Vitamin D Supplementation) randomized controlled trial of weekly vitamin D supplements (1400 IU=recommended intake) from birth to 6 months with the aim of decreasing mortality and severe morbidity. We measured plasma CRP and whole blood in-vitro production of tumour necrosis factor-α (TNFα), interferon-γ (INFγ), interleukin (IL)-10 and IL-13 following no stimulation or stimulation with lipopolysaccharide or phytohemagglutinin.RESULTS:Although the intervention improved vitamin D status in a severely deficient population, there were no differences between treatment groups in plasma CRP or in the production of any of the cytokines in either unstimulated or stimulated cultures. Recent illness had limited association with immunological markers. Plasma 25-hydroxyvitamin D levels were not associated with CRP or production of any cytokines.CONCLUSIONS:Vitamin D supplementation did not affect plasma CRP or whole blood cytokine production of vitamin D-deficient low birth weight infants. This is consistent with the lack of effect of vitamin D on mortality and severe morbidity among infants in the DIVIDS trial.European Journal of Clinical Nutrition advance online publication, 18 April 2012; doi:10.1038/ejcn.2012.33.
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