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1.
Phys Rev Lett ; 132(12): 126903, 2024 Mar 22.
Article in English | MEDLINE | ID: mdl-38579224

ABSTRACT

Adiabaticity is crucial for our understanding of complex quantum dynamics and thus for advancing fundamental physics and technology, but its impact cannot yet be quantified in complex but common cases where dynamics is only partially adiabatic, several eigenstates are simultaneously populated and transitions between noneigenstates are of key interest. We construct a universally applicable measure that can quantify the adiabaticity of quantum transitions in an arbitrary basis. Our measure distinguishes transitions that occur due to the adiabatic change of populated system eigenstates from transitions that occur due to beating between several eigenstates and can handle nonadiabatic events. While all quantum dynamics fall within the scope of the measure, we demonstrate its usage and utility through two important material science problems-energy and charge transfer-where adiabaticity could be effected by nuclear motion and its quantification will aid not only in unraveling mechanisms but also in system design, for example, of light harvesting systems.

2.
Virusdisease ; 32(4): 830-833, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34901330

ABSTRACT

Amaryllis plants showing the chlorotic stripes and yellowing of the leaves were collected. Electron microscopy of the infected plants revealed flexuous filamentous particles and disease incidence was recorded up to 64%. The presence of virus was confirmed using potyvirus genus and species-specific primers using Reverse transcription PCR. Blastn analysis showed that the samples were infected with leek yellow stripe virus (LYSV) and onion yellow dwarf virus (OYDV) the of genus Potyvirus, family Potyviridae. To the best of our knowledge, this is the first report of an association between LYSV (MZ203474 to MZ203478) and OYDV (MZ203479-MZ203482) with amaryllis. The result also showed that infected Amaryllis plants may act as a reservoir of LYSV and OYDV for economically important Allium crops.

3.
Sci Rep ; 11(1): 3799, 2021 Feb 15.
Article in English | MEDLINE | ID: mdl-33589699

ABSTRACT

Microwave spin resonance behavior of the Fe3O4 surface decorated ZnO nanocomposites (FZNC) has been investigated by ferromagnetic resonance (FMR). Modified hydrothermal method has been adopted to fabricate FZNC samples with Fe3O4 nanoparticles chains were used as seeds in the uniform magnetic field to decorate them on the surface of the ZnO nanoparticles in a unique configuration. Spin dynamics investigation confirms the transition of ZnO from diamagnetic to ferromagnetic as the sharp FMR spectra converts to the broad spectra with Fe3O4 nanoparticles incorporation. A single broad FMR spectra confirms that no isolated Fe3+ or Zn2+ ions exist which is also in agreement with XRD confirming suitable composite formation. Further, the increase in Fe3O4 concentration leads to decrease in g-value which is resulting from the internal field enhancement due to magnetic ordering. Also, various spin resonance parameters were calculated for the FZNC which provides a detail information about the magnetic ordering, exchange coupling and anisotropy. Elemental analysis confirms the presence of Fe and Zn simultaneously and transmission electron microscopy (TEM) image show the presence of Fe3O4 on the grain boundaries of ZnO which has been confirmed by taking high-resolution TEM and electron diffraction patterns on both sides of the interface. These unique structural configuration of the FZNC has tremendous potential in various magneto-optoelectronic, spintronics and electro-chemical applications.

4.
Dalton Trans ; 49(25): 8672-8683, 2020 Jul 07.
Article in English | MEDLINE | ID: mdl-32598416

ABSTRACT

Herein, we have presented a detailed investigation of the temperature effect on hydrothermal synthesis of Fe3O4 magnetic nanoparticles (MNPs). The appearance of single-phase cubic spinel Fe3O4 at and above critical temperature provides a clear indication that temperature plays a crucial role in the single-phase synthesis of the Fe3O4 MNPs. A detailed investigation of the structural, magnetic and spin dynamic properties of PEG-400 coated Fe3O4 MNPs synthesized by a facile hydrothermal method at different temperatures (120 °C, 140 °C, 160 °C and 180 °C for 16 hours) has been presented. The single-phase cubic magnetite structure with high crystallinity was found in the samples synthesized at 160 and 180 °C and confirmed from XRD results, whereas samples prepared at 120 and 140 °C are of mixed phase (α-Fe2O3 and Fe3O4). The magnetic hysteresis curves reveal that saturation magnetization and coercivity of MNPs enhanced systematically with the increase in the reaction temperature from 120 °C to 180 °C. Maximum saturation magnetization (88.98 emu g-1) and coercivity (134.16 Oe) were found for the sample synthesized at 180 °C. Furthermore, ferromagnetic resonance (FMR) spectra obtained for samples synthesised at higher temperatures indicate a lower value of the line width due to the high magnetic ordering in the samples. Also, the resonance field decreased, and the g-value increased due to enhancement in magnetization for the single-phase samples synthesized at higher reaction temperatures. The spin resonance properties obtained from fitting the FMR data clearly indicate that a large spin-orbit coupling was observed for the single phase Fe3O4 MNPs and excellent magnetic properties were obtained from the static magnetic measurements.

5.
Kathmandu Univ Med J (KUMJ) ; 18(72): 344-348, 2020.
Article in English | MEDLINE | ID: mdl-34165089

ABSTRACT

Background Iodine deficiency possesses serious threat to pregnant women and infants. During pregnancy, iodine deficiency can result in stillbirth while in infants it can lead to impaired brain development. Objective This study was conducted to assess the status of iodine deficiency among pregnant women and infants. Method Ninety seven pregnant women seeking antenatal check-up (ANC) from Chautara Hospital Sindhupalchowk were included to analyze urine iodine. Thirty one mothers and their children were followed-up for their clinical status. Additionally, the infants were assessed for their urine iodine excretion and the mothers were assessed for their awareness about iodine and iodine deficiency disorder (IDD). Result Urinary iodine excretion revealed 25.2% of pregnant women and 20% children below one year of age had insufficient iodine intake while 42.9% of pregnant women and 24% children had iodine level above normal. Almost all households were found using iodized salt, 80% respondents had heard about iodized salt, 13% mothers were aware of benefits of iodized salt, 41.9% had knowledge of iodine deficiency diseases and 38.4% cognized the source of iodine. Conclusion Though awareness about iodine and iodine deficiency disorder was satisfactory, pregnant women and children were at risk of iodine deficiency and excessive iodine disorder. Therefore, to improve health of pregnant women and newborn, their nutrition must be prioritized which ultimately will help reduce morbidity and mortality.


Subject(s)
Iodine , Malnutrition , Child , Cross-Sectional Studies , Female , Hospitals, District , Humans , Infant , Infant, Newborn , Iodine/analysis , Nepal/epidemiology , Nutritional Status , Pregnancy
6.
Nanoscale Adv ; 2(5): 1939-1948, 2020 May 19.
Article in English | MEDLINE | ID: mdl-36132523

ABSTRACT

A novel investigation on the finite-size effects on the spin resonance properties of cobalt ferrite (CoFe2O4) nanoparticles has been performed using a room temperature ferromagnetic resonance (FMR) technique. A single broad spectrum was obtained for the CoFe2O4 nanoparticle samples, which indicated that all the samples were showing ferromagnetic characteristics. An asymmetric FMR line shape with a hefty trailing section was obtained due to the high magneto-crystalline anisotropy in CoFe2O4 nanoparticles, which changed with the size distribution. The resonance field for the samples shifted to a higher value due to the increase in the magneto-crystalline anisotropy in the CoFe2O4 nanoparticles with an increase in size. A systematic change in the resonance field and line width was observed with the change in the size distribution of the particles. Initially, it decreased with an increase in the size of the particles and increased after the critical size range. The critical size range is the imprint of the shift of the magnetic domain from a single domain to multi domain. The line width increased at higher annealing temperatures due to the enhancement in the dipole-dipole interaction, which led to a higher spin concentration as well as magneto-crystalline anisotropy. Furthermore, the saturation magnetization (M s) as well as 'M r/M s' increased from 37.7 to 71.4 emu g-1 and 0.06 to 0.31, respectively. The highest coercivity (750.9 Oe) and anisotropy constant (4.62 × 104 erg cm-3) were found for the sample annealed at 700 °C, which can be corroborated by the literature as the critical annealing temperature at which CoFe2O4 nanoparticles shift from single domain nanoparticles to multi-domain nanoparticles. Post-processing annealing is critical in advanced processing techniques and spin dynamics plays a vital role in various interdisciplinary areas of applications.

7.
Kathmandu Univ Med J (KUMJ) ; 17(65): 73-76, 2019.
Article in English | MEDLINE | ID: mdl-31734684

ABSTRACT

Leprosy is a chronic infectious disease that presents with varied manifestations. Pure neuritic leprosy is one of the rarest forms of the disease which is characterized by nerve involvement without the characteristic cutaneous stigmata. Eleven year old, healthy male presented with progressively increasing painful swelling at the medial aspect of the arm near to the right elbow joint with difficulty in extending right ring and little fingers at interphalangeal joint and numbness in the same region for last 1 year with no cutaneous abnormalities. Physical examination revealed 6x3 cm firm, tender lesion 3 cm proximal to the right elbow joint with positive tinel's sign, without signs of inflammation, along with characteristic claw hand deformity of right hand and atrophy of hypothenar and interossei muscle. Electro-diagnostic testing revealed findings consistent with a right ulnar axonal neuropathy above the elbow. Magnetic resonance imaging revealed well defined heterogeneously hyper intense linear lesion along the course of thickened ulnar nerve in the distal arm extending posterior to the medial condyle. It also showed an oval shaped lesion (2.1x1.0 cm) arising from the same segment of the nerve, without any bony or muscular involvement of that area. The patient underwent surgical exploration and ulnar nerve decompression with biopsy. Pathology revealed necrotizing granulomatous inflammatory acid fast bacilli stain negative lesion, which was histologically consistent with caseous abscess caused by tuberculoid leprosy, pathognomonic for Hansen's disease. He has been started on antibiotic therapy and is referred to leprosy center for further course of management. Pure neuritic leprosy, though rare, should be considered as differential diagnosis in cases presenting with peripheral neuropathy at leprosy-endemic areas. Prompt diagnosis and treatment is imperative to prevent permanent neurological injury.


Subject(s)
Leprosy, Tuberculoid/diagnosis , Ulnar Nerve/diagnostic imaging , Abscess/diagnosis , Anti-Bacterial Agents/therapeutic use , Biopsy , Child , Diagnosis, Differential , Elbow , Humans , Leprosy, Tuberculoid/drug therapy , Leprosy, Tuberculoid/pathology , Magnetic Resonance Imaging , Male , Ulnar Nerve/pathology
8.
RSC Adv ; 9(71): 41764-41774, 2019 Dec 13.
Article in English | MEDLINE | ID: mdl-35541609

ABSTRACT

Ferromagnetism and magnetic anisotropy in Mn-Al thin films can be of great interest due to their applications in spintronic components and as rare-earth free magnets. Temperature-dependent uniaxial anisotropy has been observed in ferromagnetic MnAl thin films, which is attributed to the modification of the tetragonal lattice distortion with the change in annealing temperature, confirmed by VSM, MOKE and XRD results; the annealing time did not affect the magnetic anisotropy. A simple evaporation technique was used to deposit the Mn/Al bilayer thin films (thickness ∼ 64 nm) on GaAs substrates. A comprehensive study of the effect of annealing temperature as well as annealing time on structural, microstructural, magnetic and magneto-optical properties are reported in this paper. The ferromagnetic phase was enriched in annealed samples, which was confirmed by XRD, MOKE and magnetic hysteresis loops. XRD results revealed that the ferromagnetic τ-phase was enhanced in annealed films with the increase in annealing temperature ≥ 400 °C. Surface roughness was estimated from the AFM micrographs and was found to be increased, whereas the mean grain size was decreased on annealing the as-deposited Mn/Al bilayer thin film. The gradual increase in magnetic coercivity was found on increasing the annealing temperature. It is interesting to note that the magnetic easy axis can be tuned by changing the annealing temperature of MnAl thin films, and the easy axis changes from perpendicular to parallel direction of the film plane when the annealing temperature varies from 400 °C to 500 °C. MOKE results were also found to be consistent with the magnetic results.

9.
J Nanosci Nanotechnol ; 18(4): 2746-2751, 2018 Apr 01.
Article in English | MEDLINE | ID: mdl-29442952

ABSTRACT

We investigate the effect of dilution on dipolar interaction with linear and non-linear rheological properties of kerosene based magnetic fluid. The steady-state behavior demonstrate a shear thinning behavior and corroborated with a power law, (η = c γ ˙ n + η∞) exponent, n ≤ 1. The shear-induced-breakup (separation) of nanoparticles and the yielding behavior has been explained by Bingham model. Moreover, the magnetoviscous effect showed an initial increase at low shear rate and decrease at higher shear rate. Further, specific viscosity (ηF)-versus-Mason number (Mn) shows a perfect scaling at lower Mn (≤10-4) confirming negligible thermal and colloidal forces. Whereas, at higher Mn (≥10-3) deviation from collapse indicates the dominance of Brownian forces acting on nanofluids. The magnetic field dependent elastic (G') and viscous (G″) modulus reveal a crossover from viscoelastic-to-viscous behavior of nanofluid at critical concentration. Finally, we compare viscoelastic results with De Gans diagonal scaling theory to correlate the functional dependence of storage and loss modules with different particle volume concentration.

10.
HIV Med ; 19(4): 243-251, 2018 04.
Article in English | MEDLINE | ID: mdl-29178158

ABSTRACT

OBJECTIVES: This exploratory study examined the facilitators of and barriers to acceptance of pre-exposure prophylaxis (PrEP) and potential risk compensation behaviour emerging from its use among men who have sex with men (MSM) and transgender individuals (TGs) in India. METHODS: A questionnaire was administered to 400 individuals registered with a targeted intervention programme. Logistic regression models were used to identify facilitators of and barriers to PrEP acceptance. RESULTS: The respondents consisted of 68% MSM and 32% TGs. Risk behaviour categorization identified 40% as low risk, 41% as medium risk and, 19% as high risk for HIV infection. About 93% of the respondents were unaware of PrEP, but once informed about it, 99% were willing to use PrEP. The facilitators of PrEP acceptance were some schooling [odds ratio (OR) 2.16; P = 0.51], being married or in a live-in relationship (OR 2.08; P = 0.46), having a high calculated risk (OR 3.12; P = 0.33), and having a high self-perceived risk (OR 1.8; P = 0.35). Increasing age (OR 2.12; P = 0.04) was a significant barrier. TGs had higher odds of acceptance of PrEP under conditions of additional cost (OR 2.12; P = 0.02) and once-daily pill (OR 2.85; P = 0.04). Individuals identified as low risk for HIV infection showed lower odds of potential risk compensation, defined as more sexual partners (OR 0.8; P = 0.35), unsafe sex with new partners (OR 0.71; P = 0.16), and decreased condom use with regular partners (OR 0.95; P = 0.84), as compared with medium-risk individuals. The associations, although not statistically significant, are nevertheless important for public health action given the limited scientific evidence on PrEP use among MSM and TGs in India. CONCLUSIONS: With high acceptability and a low likelihood of risk compensation behaviour, PrEP can be considered as an effective prevention strategy for HIV infection among MSM and TGs in India.


Subject(s)
HIV Infections/prevention & control , Homosexuality, Male/psychology , Patient Acceptance of Health Care/psychology , Transgender Persons/psychology , Adult , Female , Health Knowledge, Attitudes, Practice , Health Risk Behaviors , Homosexuality, Male/statistics & numerical data , Humans , Logistic Models , Male , Odds Ratio , Patient Acceptance of Health Care/statistics & numerical data , Pre-Exposure Prophylaxis/economics , Surveys and Questionnaires , Transgender Persons/statistics & numerical data , Young Adult
11.
Public Health Action ; 5(2): 93-8, 2015 Jun 21.
Article in English | MEDLINE | ID: mdl-26400376

ABSTRACT

SETTING: Seven intervention districts with intensified childhood tuberculosis (TB) case-finding strategies implemented by a non-governmental organisation and seven control districts under the National Tuberculosis Programme, Nepal. OBJECTIVES: To assess the differences in childhood TB case registrations and case registration rates per 100 000 population between two time periods (Year 1 = March 2012-March 2013 and Year 2 = March 2013-March 2014) in intervention and control districts. DESIGN: Retrospective record review using routinely collected data. RESULTS: Childhood TB cases increased from 271 to 360 between Years 1 and 2 in the intervention districts (case registration rate from 18.2 to 24.2/100 000) and from 97 to 113 in the control districts (13.4 to 15.6/100 000): the increases were significantly higher in the intervention districts compared with the control districts. The increases were also significantly higher in children aged 0-4 years and in those with smear-negative pulmonary TB and extra-pulmonary TB. Of the various case-finding strategies, household contact screening, private-public mix services and mobile health chest camps produced the highest yield of TB. CONCLUSION: A package of intensified case-finding strategies in children was associated with an increase in childhood TB case registrations in Nepal. Additional diagnostic approaches to increase case registrations also need to be considered.


Contexte : Sept districts d'intervention avec des stratégies intensifiées de recherche active des cas de tuberculose (TB) mis en œuvre par une organisation non gouvernementale et sept districts témoins gérés par le Programme National Tuberculose au Népal.Objectifs : Evaluer les différences en termes d'enregistrement des cas de TB de l'enfant et de taux d'enregistrement pour 100 000 population entre deux périodes (année 1 = mars 2012 à mars 2013 et année 2 = mars 2013 à mars 2014) dans les districts d'intervention et les districts témoins.Schéma : Revue de dossiers rétrospective grâce aux données recueillies en routine.Résultats : Les cas de TB de l'enfant ont augmenté de 271 à 360 entre l'année 1 et l'année 2 dans les districts d'intervention (le taux d'enregistrement est passé de 18,2 à 24,2/100 000) et de 97 à 113 dans les districts témoins (13,4 à 15,6/100 000) : les augmentations ont été significativement plus importantes dans les districts d'intervention par rapport aux districts témoins. Les augmentations ont également été plus importantes chez les enfants de 0 à 4 ans et chez ceux qui ont eu une TB pulmonaire à frottis négatif et extra-pulmonaire. Parmi diverses stratégies de recherche des cas, le dépistage des contacts familiaux, les services conjoints privés-publics et les camps de santé mobiles pour la TB ont été les plus performants.Conclusion : Un paquet de stratégies intensifiées de recherche des cas a été associé à une augmentation des enregistrements de cas de TB de l'enfant au Népal. Il faut également envisager des approches diagnostiques supplémentaires pour augmenter encore l'enregistrement des cas.


Marco de referencia: Siete distritos de intervención en los cuales una organización no gubernamental aplica estrategias de búsqueda intensificada de casos de tuberculosis (TB) en los niños y siete distritos testigos del Programa Nacional contra la Tuberculosis de Nepal.Objetivos: Evaluar las diferencias en el registro de los casos de TB en la niñez y la tasa de registro de TB por 100 000 habitantes, en dos períodos (el primer año, de marzo del 2012 a marzo del 2013 y el segundo, de marzo del 2013 a marzo del 2014) en los distritos de intervención y los distritos testigos.Método: Fue este un estudio retrospectivo en el cual se analizaron los datos recogidos de manera sistemática.Resultados: Los casos de TB en la niñez aumentaron de 271 a 360 durante los períodos del estudio en los distritos de intervención (tasa de registro de casos de 18,2 a 24,2/100 000) y de 97 a 113 en los distritos testigos (de 13,4 a 15,6/100 000) y el incremento de los casos fue significativamente mayor en los distritos de intervención. Se observó un aumento con significación estadística en los niños del grupo de 0 a 4 años de edad, en los niños con TB pulmonar y baciloscopia negativa y con TB extrapulmonar. De las diferentes estrategias de búsqueda de casos, la detección sistemática de los contactos domiciliarios, los servicios mixtos público y privado y los puestos móviles de campaña de salud respiratoria alcanzaron el mayor rendimiento diagnóstico de TB.Conclusión: La introducción de un conjunto de estrategias de búsqueda intensificada de casos en los niños se asoció con un aumento en el registro de los casos de TB en Nepal. Se precisa también examinar la posibilidad de aplicar nuevos enfoques diagnósticos con el propósito de mejorar el registro de casos.

12.
Int J Tuberc Lung Dis ; 19(5): 545-51, 2015 May.
Article in English | MEDLINE | ID: mdl-25868022

ABSTRACT

SETTING: The Xpert(®) MTB/RIF assay is a highly sensitive molecular test with the potential to improve tuberculosis (TB) case detection. However, evidence supporting this potential at a programme level is minimal. METHODS: Xpert testing following smear microscopy and chest X-ray was implemented as part of routine case finding in 16 districts of Eastern Nepal. Changes in TB case notification were evaluated based on a pre/post analysis, as were expected notifications based on linear trend. RESULTS: A total of 9723 Xpert tests were performed, resulting in the identification of 1662 Mycobacterium tuberculosis-positive patients. Despite a previous declining trend in notifications, annual bacteriologically positive TB notifications increased by 15.2% during the intervention, from 3390 to 3906. However, annual notifications of pulmonary TB dropped by 8.5% overall, from 5123 to 4688. Both observations were significantly different from expected notifications based on historical trends. Treatment initiation for drug-resistant TB almost doubled. DISCUSSION: Xpert testing significantly increased bacteriologically positive TB notifications, but large reductions in empiric treatment of smear-negative disease reduced the number of pulmonary TB notifications overall. While better diagnostics remain critical, focusing solely on superior test sensitivity may not increase TB case notifications. Additional interventions are required to reach the millions of people with TB who are missed by routine services.


Subject(s)
Antitubercular Agents/administration & dosage , Communicable Disease Control/organization & administration , Disease Notification/statistics & numerical data , Molecular Diagnostic Techniques/methods , Tuberculosis, Pulmonary/diagnosis , Adolescent , Antitubercular Agents/pharmacology , Child , Child, Preschool , Confidence Intervals , DNA, Bacterial/analysis , Disease Notification/methods , Female , Humans , Male , Nepal/epidemiology , Polymerase Chain Reaction/methods , Quality Improvement , Radiography, Thoracic/methods , Sensitivity and Specificity , Sputum/microbiology , Tuberculosis, Multidrug-Resistant/diagnosis , Tuberculosis, Multidrug-Resistant/drug therapy , Tuberculosis, Pulmonary/drug therapy , Tuberculosis, Pulmonary/epidemiology , Young Adult
13.
Nepal J Ophthalmol ; 7(1): 74-8, 2015.
Article in English | MEDLINE | ID: mdl-27479993

ABSTRACT

BACKGROUND: Descemet's membrane (DM) detachment is an important cause of surgery related corneal edema that may lead to corneal decompensations and marked reduction in visual acuity if not identified and treated promptly. We prescent a case of postoperative Descemet's membrane detachment that occurred after complicated manual small incisional cataract surgery. Descemetopexy in post-cataract surgery descemet's membrane detachment has not yet been reported in Nepal. CASE: A 45 year old female underwent manual small incision cataract surgery of the right eye. Intraoperatively, there was descemet's membrane detachment so: anterior chamber tamponade with air was done. She was discharged with a visual acuity of 6/24. But on the eighth postoperative day, her visual acuity had decreased to 1/60 in right eye with corneal edema, detached descemet's membrane and descemet's folds. Hence was re-admitted for repositioning of descemet's membrane with C3F8 (14% gas mixed with air). The procedure successfully reattached the descemet's membrane. Corneal edema regressed and the gas bubble resolved after 15th day of the surgery. Patient's visual right acuity was 6/36 in right eye and the intraocular pressure was 12mmhg. CONCLUSION: DM detachment should not be taken lightly because of the potential for grave visual outcome. One needs to examine carefully, as the signs of DM detachment can be subtle and may be masked by corneal edema. During the past few years, intracameral injection with perfluoropropane (C3F8) gas has also gained increasing acceptance as an efficient and effective treatment option for Descemet's membrane detachments.


Subject(s)
Cataract Extraction/adverse effects , Corneal Diseases/surgery , Descemet Membrane/surgery , Endotamponade/methods , Fluorocarbons/administration & dosage , Corneal Diseases/etiology , Corneal Edema/physiopathology , Descemet Membrane/pathology , Female , Humans , Iatrogenic Disease , Lens Implantation, Intraocular , Middle Aged , Visual Acuity/physiology
14.
J Nanosci Nanotechnol ; 12(8): 6355-8, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22962748

ABSTRACT

Nano particles of CoGdxFe(2-x)O4, with x = 0.0, 0.1, 0.3, 0.5 have been prepared by chemical co-precipitation method. The as synthesized particles are annealed at 300 degrees C for two hours to improve crystallinity. The X-ray diffraction patterns reveal the single cobalt ferrite phase formation and the average crystallite size decreases to 7 nm in the Gd3+ ion doped sample (with x = 0.5) compared to 27 nm in case of un-doped cobalt ferrite sample. The electrical properties for the different compositions of Gd3+ ion substituted cobalt ferrite material were studied in the frequency range 100 Hz to 10 MHz at room temperature using WK impedance analyzer. It is found that the electrical conductivity of the samples increases with increasing Gd3+ ion concentration. The results of our investigations reveal a strong dependence of material properties on Gd3+ ion doping.

15.
Opt Lett ; 36(18): 3687-9, 2011 Sep 15.
Article in English | MEDLINE | ID: mdl-21931433

ABSTRACT

We report the first demonstration of on-chip cascaded stimulated Brillouin scattering (SBS). Cascaded SBS is characterized in a 4 cm long chalcogenide (As2S3) rib waveguide where the end facet reflections provide a monolithic Fabry-Perot (FP) resonator. The presence of the FP cavity reduces the Brillouin gain threshold, which enables observation of cascaded SBS at reduced pump powers. We observe up to three orders of Stokes waves in the backscattered signal at a coupled peak power of 1.34 W. Anti-Stokes waves due to four-wave mixing between the pump and the Stokes wave were observed in the forward spectrum.

16.
J Young Pharm ; 3(1): 60-4, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21607056

ABSTRACT

A contract research organization (CRO) is a company which conducts a Good Clinical Practice (GCP) in clinical trial. There are literally hundreds of CROs worldwide employing a workforce of nearly 100,000 professionals. The project proposes the study of practical parameters and their relative importance as perceived by the various stakeholders in clinical trials. The survey was conducted in Bangalore and New Delhi. Primary market data was obtained by primary market research which included 80 clinical trial stakeholders by having a preliminary communication with them, followed by administering a questionnaire along with prior permission. There were 15 Sponsors/ CROs, 27 Investigators /Monitors and 38 Ethics committee members involved in the study. It was shown from the study that a clinical investigator involved in a clinical trial is responsible for ensuring that an investigation is conducted according to the signed investigator statement, the investigational plan, and applicable regulations; for protecting the rights, safety, and welfare of the subjects under the investigator's care; and for the control of drugs under investigation. It was also shown from the study that the sponsors of a clinical trial carry the ultimate responsibility for the initiation, management and financing of the clinical trial. The study has identified a specific training need at the level of the individual stakeholder to perform a particular job function and to identify the actual practical parameters in the Indian context important for the conduction of clinical trials (GCP) with respect to the different stakeholders, to determine the relative importance of these parameters as perceived by various stakeholders involved in clinical trials, and to identify the relative contributions of different stakeholders to the success/ satisfactory conduct of a clinical trial.

17.
Clin Oncol (R Coll Radiol) ; 22(5): 374-81, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20466282

ABSTRACT

AIMS: Extraskeletal Ewing's sarcoma (EES) is a rare form of soft tissue sarcoma. The aim of the present study was to assess the outcome and the prognosis of adult patients presenting with EES treated with multi-modality therapy. MATERIALS AND METHODS: All EES patients older than 15 years referred to our institution between January 1995 and December 2004 were reviewed. In total, 57 patients were identified. Their median age at diagnosis was 20 years (range 15-57). RESULTS: The median size of the primary tumour was 11 cm (range 4-30 cm). Eighteen patients (31%) had metastatic disease at initial presentation. Wide surgical resection with negative margins was achieved in 23 cases (40%). Chemotherapy consisting of vincristine, adriamycin, ifosfamide, actinomycin D was given in 50 patients (88%). Radiotherapy was delivered in 37 patients (65%). Forty-one patients (72%) achieved complete remission and 16 (28%) progressed on therapy. Twenty-one patients (51%) relapsed. Local recurrence was encountered in 15 patients (36%). At a median follow-up of 46 months (range 6-143 months), the 5-year event-free survival and overall survival rates were 35 and 47%, respectively. Metastases at presentation, tumour size and surgical resection margin associated significantly with overall survival and event-free survival. CONCLUSION: EES is an aggressive type of tumour with a high incidence of local recurrence and distant metastasis. This series showed that the outcome of adult EES is not unlike that of skeletal Ewing's sarcoma in terms of response to multi-modality treatment and the prognostic factors influencing treatment outcome. Adequate surgical resection, aggressive chemotherapy and adjuvant local radiation therapy, when indicated, constitute the optimal treatment to achieve the best results in this rare type of disease.


Subject(s)
Sarcoma, Ewing/pathology , Sarcoma, Ewing/therapy , Sarcoma/pathology , Sarcoma/therapy , Adolescent , Adult , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Combined Modality Therapy , Dactinomycin/administration & dosage , Disease-Free Survival , Doxorubicin/administration & dosage , Humans , Ifosfamide/administration & dosage , Kaplan-Meier Estimate , Middle Aged , Radiotherapy , Sarcoma/mortality , Sarcoma, Ewing/mortality , Vincristine/administration & dosage , Young Adult
19.
Clin Oncol (R Coll Radiol) ; 21(10): 775-80, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19875275

ABSTRACT

AIMS: Aggressive fibromatosis is a locally aggressive infiltrative low-grade tumour, although pathologically benign, and it does not metastasise, yet it can cause serious local distressing symptoms by virtue of local destruction and impairment of local function. The aim of this study was to emphasise the role of radiotherapy and adequate surgery in the treatment of fibromatosis in patients presenting with newly diagnosed or recurrent disease and to analyse our treatment results over 15 years for this rare tumour type. MATERIALS AND METHODS: Fifty-four patients with confirmed diagnosis of aggressive fibromatosis treated at King Faisal Specialist Hospital between 1990 and 2006 were identified from our local cancer registry. Forty-seven patients had surgery: complete resection (R0) in 20 patients, incomplete surgery (R1/2) in 27 patients, and seven patients had biopsy only. Forty-five patients were treated with radiotherapy: 38 patients were treated with postoperative radiotherapy, three patients were treated with preoperative radiotherapy and four patients had radiotherapy as the only treatment. The radiotherapy dose ranged between 45 and 60Gy (median 50.4Gy). Three patients did not receive any form of treatment apart from biopsy, but were still included in the final analysis. RESULTS: Fifty-two per cent (28/54 patients) of our patient population had tumour recurrence when first presented to King Faisal Specialist Hospital. The median age was 29.5 years (range 2-63 years). The most common site of involvement was the extremities (28 patients). Among the 54 patients (with primary and recurrent presentation) there were 10 local recurrences, all of which were within the original primary site. The 5-year progression-free survival and overall survival rates for the whole group were 75 and 95%, respectively. Univariate and multivariate Cox regression analysis showed that the depth of invasion significantly affected progression-free survival. CONCLUSION: Aggressive fibromatosis is effectively treated with surgery and postoperative radiotherapy. Patients first presenting with tumour recurrence may still have local tumour control comparable with newly diagnosed patients.


Subject(s)
Fibroma/radiotherapy , Fibroma/surgery , Adolescent , Adult , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Retrospective Studies , Severity of Illness Index , Treatment Outcome , Young Adult
20.
Kathmandu Univ Med J (KUMJ) ; 7(26): 177-82, 2009.
Article in English | MEDLINE | ID: mdl-20071856

ABSTRACT

INTRODUCTION: Many doctors are leaving Nepal to work abroad. To understand this problem better, we decided to study the attitude and plans of young doctors and medical students. MATERIALS AND METHODS: This cross-sectional study was conducted at Kathmandu Medical College involving 65 first year medical students, 100 interns and 100 house officers. The data collected was entered in Microsoft excel and analysed by SPSS (Statistical Package for Social Sciences) programme. Chi-square test was used to compare two proportions. Significance level was set at 5%. RESULTS: Only 2% house officers said that their job prospects were excellent as compared to 22.4% of students, whereas 20% house officers as compared to 9% students thought job prospects in Nepal were poor (p= 0.003). Eighty two percent of students thought that a doctor's service to his country was very important as compared to 51% of interns (p= 0.001) and 58% of house officers. Forty percent of students, 58% of interns and 48% of house officers (no statistical significance between the three groups) planned to migrate to a developed country after graduation. Eighty eight percent of students, 89% interns and 74% of house officers (no statistical significant differences between the three groups) were of the opinion that improving career opportunities or working environment of the doctor could make the profession more attractive. CONCLUSION: Although majority of students, interns and house officers were of the opinion that a doctor's service to his community/country was very important, almost half of them still planned to migrate to a developed country after graduation. Improving the chances of professional advancement and professional working environment can make the profession more attractive, and therefore, may decrease this tendency for brain drain from our country.


Subject(s)
Career Mobility , Emigration and Immigration/trends , Internship and Residency , Physicians/psychology , Students, Medical/psychology , Attitude of Health Personnel , Career Choice , Humans , Job Satisfaction , Nepal
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