Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 67
Filtrar
Más filtros

País/Región como asunto
Intervalo de año de publicación
1.
Med J Armed Forces India ; 79(3): 300-308, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37193519

RESUMEN

Background: Hospital administrators are often challenged with overcrowding at hospitals. The study hospital receives referred patients; however, they have to wait in long queues even for getting registered. This was a cause of concern for hospital administrators. The study was undertaken to find an amicable solution to the queues at registration using Queuing Theory. Method: This observational and interventional study was carried out in a tertiary care ophthalmic hospital. In the first phase, data of service time and arrival rate was collected. The queuing model was built using the coefficient of variation (CoV) of the observed times. Server utilization for new patient registration was found to be 1.21 and was 0.63 for revisit patients. Scenario-based simulation carried out using free software for optimal utilization of both types of servers. Recommendations made to combine the registration process and to increase one server were implemented.In the second phase, after one year, patient registration data were collected and compared for the number of patients registered using SPSS 17. Results: Number of patients registered within the registration timings increased whereas the number of patients registered after the registration timings decreased significantly at 95% CI with a p-value of less than 0.001. Queues finished early and more number of patients were registered in the same time. Conclusion: Using queuing theory, the bottleneck of the systems can be identified. Scenario and software-based simulations provide solutions to the problem of queues. The study is an application of Queuing Theory with a focus on efficient resource utilization. It can be replicated in an organization with limited resources facing the challenge of queues.

2.
Georgian Med News ; (343): 98-103, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38096524

RESUMEN

The Corona Virus (COV-19) epidemic significantly affected the educational environment, requiring a quick transition to distance and blended learning methods. This extraordinary disruption had an incredible impact on pupil's levels of physical activity (PA), psycho-emotional health (PEH) and engagement with academic material. The research aims to examine the vital determinants that influenced various areas of learners' lives during CoV-19. The purpose of this 600-person study was to collect data on the subjects' overall health and PA levels for the CoV-19 pandemic. The SPSS application was used to process the questionnaire's collected data. The information given reveals the respondents' degree of PA throughout the quarantine. According to the breakdown, 15% indicated low levels of PA, 39% reported medium levels and 46% reported high levels. The data show that, despite the respondents' different levels of PA, little PA predominated for most of them. The limitations of distance learning throughout quarantine and the prevalent recommendation of leaving residence for necessary reasons were blamed for this tendency. There were fewer prospects for higher-intensity PA due to these circumstances.


Asunto(s)
COVID-19 , Humanos , Emociones , Ejercicio Físico , Pandemias
3.
Med J Armed Forces India ; 78(Suppl 1): S163-S171, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36147384

RESUMEN

Background: Cancellation of surgeries is a regular phenomenon in any hospital, and reasons may vary from clinical to managerial ones. The aim of the study is to suggest scheduling to address the problem of time over run related cancellations. This is an observational and descriptive study conducted in a tertiary care hospital with ophthalmology facilities. The sample size is calculated with 95% confidence interval using Epi Info 6 from the total surgeries performed in the last 5 years (n = 380). Simple random sampling technique was used. Methods: Surgical time for all types of ophthalmic surgeries (n = 582) was observed. Allocation of listed cases to the available operating rooms (ORs) was carried out using the observed time using LEKIN software. Results: The time over-run of 2 h and 6 h was noted for two units, whereas idle OR time was observed in other units. An average idle time of 19% was noted on each day. Reallocation of the cases to the ORs was carried out taking all the planned cases (of both the operating units of the day) as the number of jobs and all the available ORs as parallel machines using LEKIN software. All the planned cases could be accommodated; still, an average of 17% of the total available operation theater (OT) time was found idle on each day. Conclusions: Planning of cases using procedure time and scheduling on a daily basis using allocation models with simple algorithms can provide optimal utilization of OTs and can address the time over-run and related cancellations.

4.
Kathmandu Univ Med J (KUMJ) ; 18(71): 279-283, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-34158437

RESUMEN

Background Periodontitis has a multifactorial etiology, and the pathogenic bacteria that reside in the subgingival area are the primary etiologic agent. Objective The study aimed to evaluate the clinical efficacy and benefits of herbal chip and gel made from extracts of Punica granatum as a subgingival adjunct to scaling and root planing (SRP). Method A randomized control clinical trial was conducted on 30 systemically healthy patient's sites having chronic periodontitis, and they were randomly allocated to into three treatment groups followed by Scaling and Root Planing in all patients. Group 1 - Ten patients received Scaling and Root Planing and Punica granatum chip at selected sites. Group 2 - Ten patients received Scaling and Root Planing and punica granatum gel at selected sites. Group 3 - Ten patients with Scaling and Root Planing alone. Clinical parameters were recorded at baseline, 21 days and at 45 days which included plaque index (PI), gingival index (GI), probing pocket depth (PPD) and relative attachment level (RAL). Result Plaque Index and Gingival index showed better reduction in group I compared to group II and group III at 21st day 45th day follow up. Analysing Pocket Probing Depth the intergroup comparison revealed similar results with maximum reduction being seen in group I from baseline to 21 and baseline to 45 days (p < 0.001). On analysing Relative Attachment Loss revealed reduction in all three groups with maximum reduction in group I from baseline to 45 days and reduction in group III was not statistically significant (p < 0.090). Conclusion The study concluded that Punica granatum chip as an adjunct to Scaling and Root Planing was more effective than Punica granatum gel and scaling and root planing alone.


Asunto(s)
Periodontitis Crónica , Granada (Fruta) , Periodontitis Crónica/tratamiento farmacológico , Humanos , Índice Periodontal , Aplanamiento de la Raíz , Resultado del Tratamiento
5.
Gene Ther ; 25(1): 20-26, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29057994

RESUMEN

Enhanced afferent excitability is considered to be an important pathophysiological basis of interstitial cystitis/bladder pain syndrome (IC/BPS). In addition, transient receptor potential vanilloid-1 (TRPV1) receptors are known to be involved in afferent sensitization. Animals with hydrogen peroxide (HP)-induced cystitis have been used as a model exhibiting pathologic characteristics of chronic inflammatory condition of the bladder. This study investigated the effect of gene therapy with replication-defective herpes simplex virus (HSV) vectors encoding poreless TRPV1 (PL) or protein phosphatase 1 α (PP1α), a negative regulator of TRPV1, using a HP-induced rat model of cystitis. HSV vectors encoding green fluorescent protein, PL or PP1α were inoculated into the bladder wall of female rats. After 1 week, 1% HP or normal saline was administered into the bladder, and the evaluations were performed 2 weeks after viral inoculation. In HP-induced cystitis rats, gene delivery of PL or PP1α decreased pain behavior as well as a reduction in the intercontraction interval. Also, both treatments reduced nerve growth factor expression in the bladder mucosa, reduced bladder inflammation characterized by infiltration of inflammatory cells and increased bladder weight. Taken together, HSV-mediated gene therapy targeting TRPV1 receptors could be effective for the treatment of IC/BPS.


Asunto(s)
Cistitis/inducido químicamente , Cistitis/terapia , Terapia Genética/métodos , Vectores Genéticos , Peróxido de Hidrógeno/toxicidad , Proteína Fosfatasa 1/genética , Simplexvirus/genética , Canales Catiónicos TRPV/genética , Animales , Cistitis/enzimología , Cistitis/metabolismo , Virus Defectuosos/genética , Modelos Animales de Enfermedad , Femenino , Expresión Génica , Proteínas Fluorescentes Verdes/genética , Tamaño de los Órganos , Ratas , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/patología
6.
Indian J Public Health ; 61(3): 174-181, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28928300

RESUMEN

BACKGROUND: The global resurgence of rickettsial diseases and their potential to impact the fitness of military personnel and inflict widespread casualties amongst civil populations has emerged as a major cause of public health concern. Absence of surveillance system, lack of awareness amongst medical fraternity to rickettsial activity along with the difficulty in diagnosis because of their protean clinical manifestations are reasons for the outbreaks of these diseases. OBJECTIVES: To determine rickettsial activity amongst rodents and study vector diversity, abundance and their distribution to enable mapping of rickettsial hotspots. METHODS: Zoonotic surveillance was undertaken in six selected study areas in India - Jammu, Akhnoor, Rajouri-Poonch, Udhampur-Nagrota, Dehradun and Pune. Weil-Felix test was used for rickettsial sero-surveillance amongst rodents and standard identification keys were used for mapping vector diversity and database preparation. RESULTS: Serological findings revealed positivity to all the three rickettsial antigens (OXK, OX19 and OX2) in Jammu, OX19 in Dehradun and OXK and OX2 positivity in Udhampur-Nagrota belt. The vector database records presence of 16 species of trombiculid mites from three important genera - Leptotrombidium, Schoengastiella and Gahrliepia with ticks from five genera and 8 species of fleas from four genera. Mite fauna of study sites has been enriched with addition of new records of mite species (five mite species at Pune, two at Akhnoor with one mite species each at Jammu and Dehradun). CONCLUSION: The study reveals rickettsial activity amongst rodents at Jammu, Dehradun and Udhampur-Nagrota belt. The results correlate well with the presence of vectors of scrub and tick typhus and corroborate the occurrence of outbreaks of these diseases in the respective areas.


Asunto(s)
Vectores de Enfermedades , Infecciones por Rickettsia/epidemiología , Rickettsia/aislamiento & purificación , Zoonosis , Animales , Reservorios de Enfermedades , India/epidemiología , Roedores/microbiología , Roedores/parasitología
7.
Spinal Cord ; 53(3): 190-194, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25535154

RESUMEN

OBJECTIVES: This study investigated the mechanisms inducing autonomic dysreflexia due to enhanced bladder-to-vascular reflexes in rats with spinal cord injury (SCI). METHODS: SCI was produced by the transection of the Th4-5 spinal cord in female Sprague-Dawley rats. At 4 weeks after SCI, changes in blood pressure during graded increases in intravesical pressure (20-60 cm H2O) were measured in spinal-intact (SI) and SCI rats under urethane anesthesia. In five animals, effects of C-fiber desensitization induced by intravesical application of resiniferatoxin (RTX), a TRPV1 agonist, on the bladder-to-vascular reflex were also examined. Nerve growth factor (NGF) levels of mucosa and detrusor muscle layers of the bladder were measured by enzyme-linked immunosorbent assay. The expression levels of TRPV1 and TRPA1 channels were also examined in laser captured bladder afferent neurons obtained from L6 DRG, which were labeled by DiI injected into the bladder wall. RESULTS: In SI and SCI rats, systemic arterial blood pressure was increased in a pressure-dependent manner during increases in the intravesical pressure, with significantly higher blood pressure elevation at the intravesical pressure of 20 cm H2O in SCI rats vs SI rats. The arterial blood pressure responses to bladder distention were significantly reduced by RTX-induced desensitization of C-fiber bladder afferent pathways. SCI rats had higher NGF protein levels in the bladder and higher TRPV1 and TRPA1 mRNA levels in bladder afferent neurons compared with SI rats. CONCLUSIONS: The bladder-to-vascular reflex induced by TRPV1-expressing C-fiber afferents during bladder distention is enhanced after SCI in association with increased expression of NGF in the bladder and TRP channels in bladder afferent neurons.

8.
Parasitol Res ; 114(9): 3487-96, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26113507

RESUMEN

Antimalarial drug resistance including artemisinin resistance in Plasmodium falciparum malaria is a major concern in combating malaria throughout the world. Delayed parasite clearance time (PCT) is indicative of emergence of artemisinin resistance. Herein, PCT has been monitored with the help of gold standard technique microscopy accompanied by a more sensitive real-time assay for academic purpose. After the administration of artemisinin based combination therapy, artesunate + sulfadoxine pyrimethamine (AS + SP), all the subjects were followed up to day 42 for monitoring the therapeutic efficacy of AS + SP in Bisra Community Health Centre (CHC), Sundergarh district in the state of Odisha in India. Further, representative samples were analyzed for L263E, E431K, A623E and S769N SNPs in Pfatpase6 gene and copy number polymorphisms in Pfmdr1 gene. Though all the samples were found parasite negative according to microscopy by the end of day 3 and attained adequate clinical and parasitological response (ACPR) at the end of day 42, real-time PCR showed day 3 positivity in 12 of the total analyzed samples (n = 43). This was further validated by end-point diagnostic PCR and correlated with high initial parasite load. E431K mutation was observed in 2 of the 12 samples (16.7 %) while the controls (n = 18) were all wild. L263E, A623E and S769N were wild in all the analyzed samples (n = 30). Pfmdr1 copy number analysis showed no change in the said trait. Conclusively, real-time PCR could support microscopy for better monitoring of PCT and may provide as an additional but useful research tool for artemisinin resistance studies.


Asunto(s)
Antimaláricos/farmacología , Artemisininas/farmacología , Resistencia a Medicamentos/genética , Malaria Falciparum/parasitología , Plasmodium falciparum/genética , Pirimetamina/farmacología , Sulfadoxina/farmacología , Adolescente , Adulto , Animales , Niño , Preescolar , Femenino , Dosificación de Gen , Humanos , India , Malaria Falciparum/tratamiento farmacológico , Masculino , Microscopía , Persona de Mediana Edad , Mutación , Plasmodium falciparum/efectos de los fármacos , Reacción en Cadena en Tiempo Real de la Polimerasa , Adulto Joven
9.
J Clin Pediatr Dent ; 37(3): 301-5, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23855176

RESUMEN

OBJECTIVE: To evaluate and compare the behavioral changes and effect of sedative techniques in pediatric dental patients using Oral Midazolam, Intravenous Midazolam and Oral Diazepam as sedative agents. METHOD: Triple blind randomized control trial with 40 patients aged between 2-10 years, exhibiting definitely negative behavior was considered. Patients were randomly assigned to one of the four treatment groups. Group I received midazolam 0.5 mg/kg orally, Group II received 0.5 mg/kg diazepam orally, Group III received 0.06 mg/kg midazolam intravenously and Group IV received oral placebo. Behavioral changes (sleep, crying, movement, and overall behavior) and effect of sedative techniques on pediatric patients were assessed. RESULTS: All the patients in group 3 were significantly better in post administrative behavior viz. sleep, crying and movement. Over all behavior scores for group 3 patients were significantly better than other three groups (p < 0.001). Positive behavior of patients in group 2 and 3 did not show significant difference but positive behavior in group 3 was significantly (p < 0.05) more than group 2. Placebo group showed the highest negative behavior CONCLUSION: Sedative effects of oral midazolam and oral diazepam were comparable, where as intravenous midazolam produced more sedation. Anxiolysis was found to be more in both the midazolam groups than the diazepam group. Most number of positive changes were observed in midazolam groups as compared to diazepam group.


Asunto(s)
Conducta Infantil/efectos de los fármacos , Atención Odontológica , Diazepam/administración & dosificación , Hipnóticos y Sedantes/administración & dosificación , Midazolam/administración & dosificación , Administración Oral , Anestesia Dental/métodos , Anestésicos Locales/administración & dosificación , Ansiolíticos/uso terapéutico , Presión Sanguínea/efectos de los fármacos , Monitores de Presión Sanguínea , Niño , Preescolar , Sedación Consciente/métodos , Llanto , Operatoria Dental/instrumentación , Método Doble Ciego , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Inyecciones Intravenosas , Masculino , Midazolam/uso terapéutico , Movimiento/efectos de los fármacos , Oximetría/instrumentación , Placebos , Respiración/efectos de los fármacos , Sueño/efectos de los fármacos
10.
Clin Infect Dis ; 55(5): 663-71, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22586253

RESUMEN

BACKGROUND: Artemisinin-based combination therapy is the first-line treatment for uncomplicated falciparum malaria. This study assessed the antimalarial efficacy and safety of a combination of 150 mg of arterolane maleate and 750 mg of piperaquine phosphate (AM-PQP) in comparison to Coartem (artemether and lumefantrine) in patients with acute uncomplicated P. falciparum malaria. METHODS: In this open-label, randomized, multicentric, parallel group clinical trial, 240 patients were randomized to receive AM-PQP (160 patients) or Coartem (80 patients). Patients with P. falciparum monoinfection and initial parasite densities ranging from 1000 to 100 000 asexual parasites/µL of blood were followed for 28 days. Polymerase chain reaction-corrected adequate clinical and parasitologic response on day 28, parasite clearance time, and fever clearance time were evaluated. RESULTS: A total of 151 (94.4%) of 160 patients in the AM-PQP group completed the trial, while 77 (96.3%) of 80 patients in the Coartem group completed the trial. No treatment failure was noted in the AM-PQP group, while one patient receiving Coartem failed treatment on day 28. There was no difference in the median parasite clearance time (30 hours in both groups) or median fever clearance time (24 hours in both groups) after administration of the 2 study treatments. CONCLUSIONS: The available data support the evaluation of a drug combination in a larger population as a fixed-dose combination. Clinical Trials Registration. CTRI/2007/091/000031.


Asunto(s)
Antimaláricos/uso terapéutico , Compuestos Heterocíclicos con 1 Anillo/uso terapéutico , Malaria Falciparum/tratamiento farmacológico , Peróxidos/uso terapéutico , Quinolinas/uso terapéutico , Compuestos de Espiro/uso terapéutico , Adolescente , Adulto , Antimaláricos/efectos adversos , Antimaláricos/farmacocinética , Femenino , Compuestos Heterocíclicos con 1 Anillo/efectos adversos , Compuestos Heterocíclicos con 1 Anillo/farmacocinética , Humanos , Estimación de Kaplan-Meier , Malaria Falciparum/metabolismo , Malaria Falciparum/parasitología , Masculino , Peróxidos/efectos adversos , Peróxidos/farmacocinética , Quinolinas/efectos adversos , Quinolinas/farmacocinética , Compuestos de Espiro/efectos adversos , Compuestos de Espiro/farmacocinética , Estadísticas no Paramétricas
11.
Clin Infect Dis ; 51(6): 684-91, 2010 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-20687837

RESUMEN

BACKGROUND: Drug-resistant Plasmodium falciparum malaria necessitates development of novel drugs for treatment.The present study assessed the efficacy and safety of 3 dose levels of arterolane (RBx 11160), a synthetic trioxolane, for treatment of acute uncomplicated falciparum malaria. METHODS: In this randomized, double-blind, multicenter, parallel-group, dose-finding, phase II trial, 230 patients from 4 centers in Thailand, India, and Tanzania (mainland and Zanzibar) received either 50 mg (n=78), 100mg (n=76), or 200 mg (n=76) of arterolane once daily for 7 days. Patients (aged 13-65 years) with asexual parasite density of 1000-100,000 parasites/microL were included and were followed up for 28 days. The median time to 90% parasite clearance (PC90) was evaluated. RESULTS: The median PC90 was longer in the group receiving the 50-mg dose (19.4 h), compared with the groups receiving the 100-mg dose (12.8 h) and 200-mg dose (12.6 h) (P < .01). The polymerase chain reaction-corrected adequate clinical and parasitological responses on day 28 were 63%, 71%, and 72% for the groups receiving the 50-mg, 100-mg, and 200-mg doses, respectively, by intention-to-treat analysis (odds ratio, 1.55; 95%confidence interval, 0.78-3.06, for comparison of the 200-mg and 50-mg dose groups). Treatment was generally well tolerated. No patient died or experienced any serious adverse event. Mild complaints were reported in <10%of the patients and were similar in the 3 groups. Biochemistry and hematological analyses did not show any signof drug toxicity in any patient. CONCLUSION: Arterolane at daily doses of 100 and 200 mg is a rapidly acting, effective, and safe synthetic antimalarial drug, which may potentially represent an alternative to artemisinin derivatives in antimalarial combination therapy. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT00362050.


Asunto(s)
Antimaláricos/administración & dosificación , Compuestos Heterocíclicos con 1 Anillo/administración & dosificación , Malaria Falciparum/tratamiento farmacológico , Peróxidos/administración & dosificación , Plasmodium falciparum/aislamiento & purificación , Compuestos de Espiro/administración & dosificación , Adolescente , Adulto , Anciano , Antimaláricos/efectos adversos , Antimaláricos/farmacología , Método Doble Ciego , Femenino , Compuestos Heterocíclicos con 1 Anillo/efectos adversos , Compuestos Heterocíclicos con 1 Anillo/farmacología , Humanos , India , Masculino , Persona de Mediana Edad , Peróxidos/efectos adversos , Peróxidos/farmacología , Plasmodium falciparum/efectos de los fármacos , Compuestos de Espiro/efectos adversos , Compuestos de Espiro/farmacología , Tanzanía , Tailandia , Resultado del Tratamiento , Adulto Joven
12.
J Nanosci Nanotechnol ; 20(6): 3839-3844, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-31748084

RESUMEN

The GaN nanoporous-film (NPF) and nanorods (NRs) were grown on sapphire (0001) using laserassisted molecular beam epitaxy (LMBE) technique by laser ablating solid GaN target at different laser energy density. The interconnected GaN NPF was grown at low laser energy density of ˜4 J/cm² whereas vertically aligned GaN NRs was obtained at high laser energy density of ˜7 J/cm². The pore size of the GaN NPF structure is in range of 40-120 nm. The GaN NRs possess hexagonal shape with six sidewall facets and truncated top facet. The length, width and density of GaN NRs are 600-900 nm, 150-250 nm and ˜2.5×107 cm-2, respectively. The X-ray rocking curve full width at half maximum values along GaN (0002) and (1012) planes for GaN NRs obtained to be 0.41 and 0.53°, respectively. The biaxial stress in hetero-epitaxially grown GaN was investigated with Raman spectroscopy and it was found that GaN NRs possesses a very low in-plane compressive biaxial stress of 0.09 GPa. The photoluminescence study exhibits a sharp band-to-band emission at 3.4 eV with a peak line width of 140 meV, signifying the good optical quality of the LMBE grown GaN NRs on sapphire (0001).

13.
J Nanosci Nanotechnol ; 20(6): 3866-3872, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-31748088

RESUMEN

The optical properties of laser-assisted molecular beam epitaxy grown homo-epitaxialGaN nanowall networks (NWNs) were investigated using power dependent photoluminescence (PL) spectroscopy and compared with homo-epitaxial GaN thin film. The pore size and tip width of GaN NWN sample is ˜120-180 nm and 10-15 nm, respectively. The ultraviolet-visible spectroscopy study shows that the GaN NWNs have low optical light reflection and minimum Fabry-Perot cavity effect than GaN film. The room temperature PL spectroscopy reveals that the GaN NWNs possesses enhanced band gap of 3.51 eV with blue shift of 90 meV than the GaN film (3.42 eV). The excitation density dependent PL spectroscopy measurements reveal that the GaN NWNs nanowall and near band emission (NBE) peak position and its linewidth invariant. The intensity of NBE peak for GaN film and nanowalls varies linearly whereas NBE to defect related yellow luminescence peak intensity ratio shows a non-linear variation on the excitation density. The excitation density in PL measurements plays a key role when the sample quality compared on the basis of PL data.

14.
RSC Adv ; 10(4): 2113-2122, 2020 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-35494595

RESUMEN

The effect of flexible Ti metal foil surface modification and laser repetition rate in laser molecular beam epitaxy growth process on the evolution of GaN nanorods and their structural, electronic and optical properties has been investigated. The GaN nanostructures were grown on bare- and pre-nitridated Ti foil substrates at 700 °C for different laser repetition rates (10-30 Hz). It is found that the low repetition rate (10 Hz) promotes sparse growth of three-dimensional inverted-cone like GaN nanostructures on pre-nitridated Ti surface whereas the entire Ti foil substrate is nearly covered with film-like GaN consisting of large-sized grains for 30 Hz growth. In case of the GaN growth at 20 Hz, uniformly-aligned, dense (∼8 × 109 cm-2) GaN nanorods are successfully grown on pre-nitridated Ti foil whereas sparse vertical GaN nanorods have been obtained on bare Ti foil under similar growth conditions for both 20 and 30 Hz. X-ray photoemission spectroscopy (XPS) has been utilized to elucidate the electronic structure of GaN nanorods grown under various experimental conditions on Ti foil. It confirms Ga-N bonding in the grown structures, and the calculated chemical composition turns out to be Ga rich for the GaN nanorods grown on pre-nitridated Ti foil. For bare Ti substrates, a preferred reaction between Ti and N is noticed as compared to Ga and N leading to sparse growth of GaN nanorods. Hence, the nitridation of Ti foil is a prerequisite to achieve the growth of dense and aligned GaN nanorod arrays. The X-ray diffraction, high resolution transmission electron microscopy and Raman studies revealed the c-axis growth of wurtzite GaN nanorods on Ti metal foil with good crystallinity and structural quality. The photoluminescence spectroscopy showed that the dense GaN nanorod possesses a near band edge emission at 3.42 eV with a full width at half maximum of 98 meV at room temperature. The density-controlled growth of GaN nanorods on a flexible substrate with high structural and optical quality holds promise for potential applications in futuristic flexible GaN based optoelectronics and sensor devices.

15.
J Nanosci Nanotechnol ; 20(6): 3929-3934, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-31748098

RESUMEN

We report the direct growth of crystalline GaN on bare copper (Cu) and monolayer-graphene/Cu metal foils using laser molecular beam epitaxy technique at growth temperature of 700 °C. The surface morphology investigated with field emission scanning electron microscopy revealed that the size of GaN grains for film grown on bare Cu falls in range of 90 to 160 nm whereas large grains with size of ˜200 to 600 nm was obtained for GaN grown on graphene/Cu foil under similar growth condition. The transverse optical mode of cubic GaN and E2 (high) phonon mode for wurtzite GaN phases were obtained on the GaN film grown on Cu and graphene/Cu metal foils as deduced by Raman spectroscopy. The photoluminescence (PL) spectroscopy studies showed that the near band edge emission peaks for GaN on Cu and graphene/Cu consist two major peaks at 3.26 and 3.4 eV, corresponding to cubic and wurtzite GaN, respectively. The Raman and PL studies disclosed that the mixed phase growth of GaN occurs on these foils and better structural and optical quality for GaN on graphene/Cu foil. The direct growth of GaN on two dimensional graphene on polycrystalline metal foils is beneficial various transferrable and flexible opto-electronics device applications.

16.
Gene Ther ; 16(1): 26-33, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18668142

RESUMEN

Neurturin (NTN), a member of glial cell line-derived neurotrophic factor (GDNF) family, is known as an important neurotrophic factor for penis-projecting neurons. We recently demonstrated significant protection from erectile dysfunction (ED) following a replication-defective herpes simplex virus (HSV) vector-mediated GDNF delivery to the injured cavernous nerve. Herein, we applied HSV vector-mediated delivery of NTN to this ED model. Rat cavernous nerve was injured bilaterally using a clamp and dry ice. For HSV-treated groups, 20 microl of vector stock was administered directly to the damaged nerve. Delivery of an HSV vector expressing both green fluorescent protein and lacZ (HSV-LacZ) was used as a control. Intracavernous pressure along with systemic arterial pressure (ICP/AP) was measured 2 and 4 weeks after the nerve injury. Fluorogold (FG) was injected into the penile crus 7 days before being killed to assess neuronal survival. Four weeks after nerve injury, rats treated with HSV-NTN exhibited significantly higher ICP/AP compared with untreated or control vector-treated groups. The HSV-NTN group had more FG-positive major pelvic ganglion neurons than the control group following injury. HSV vector-mediated delivery of NTN could be a viable approach for the improvement of ED following cavernous nerve injury.


Asunto(s)
Disfunción Eréctil/terapia , Terapia Genética/métodos , Vectores Genéticos/administración & dosificación , Neurturina/genética , Pene/lesiones , Simplexvirus/genética , Animales , Biomarcadores/análisis , Disfunción Eréctil/etiología , Disfunción Eréctil/metabolismo , Ganglios Espinales/metabolismo , Ganglios Espinales/patología , Expresión Génica , Vectores Genéticos/genética , Proteínas Fluorescentes Verdes/genética , Inmunohistoquímica , Masculino , Modelos Animales , Regeneración Nerviosa , Neurturina/análisis , Neurturina/metabolismo , Óxido Nítrico Sintasa de Tipo I/análisis , Pene/inervación , Ratas , Ratas Sprague-Dawley , Transducción Genética/métodos , Tirosina 3-Monooxigenasa/análisis
17.
Anal Chem ; 81(24): 9979-84, 2009 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-19904993

RESUMEN

Spatially resolved electrochemical recording of neurochemicals is difficult due to the challenges associated with producing nanometer-scale patternable and integrated sensors. We describe the lithographic fabrication and characterization of patternable gold (Au) nanowire (NW) based sensors for the electrochemical recording of dopamine (DA). We demonstrate a straightforward NW-size-independent approach to align contact pads to NWs. Sensors, with NW widths as small as 30 nm, exhibited considerable insensitivity to scan rates during cyclic voltammetry, a nonlinear increase in oxidation current with increasing NW width, and the selectivity to measure submaximal synaptic concentrations of DA in the presence of interfering ascorbic acid. The electrochemical sensitivity of Au NW electrode sensors was much larger than that of Au thin-film electrodes. In chronoamperometric measurements, the NW sensors were found to be sensitive for submicromolar concentration of DA. Hence, the patternable NW sensors represent an attractive platform for electrochemical sensing and recording.


Asunto(s)
Dopamina/análisis , Oro/química , Nanopartículas del Metal/química , Nanocables/química , Electroquímica , Electrodos , Tamaño de la Partícula , Propiedades de Superficie
19.
J Med Entomol ; 46(2): 342-50, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19351086

RESUMEN

A village-scale trial was conducted on the efficacy of Olyset nets: a long-lasting insecticidal net (LLIN) factory treated with 2% wt:wt permethrin against malaria vectors Anopheles culicifacies Giles and Anopheles fluviatilis James, in Sundargarh District, Orissa, India. The study area comprised 22 villages that were randomized into three clusters and designated as Olyset net, untreated net, and no net clusters. Baseline studies showed that both vector species were 100% susceptible to permethrin. Results of wash resistance and bioefficacy of Olyset nets showed 100% mortality in An. culicifacies up to 11 washings, whereas 100% mortality was observed in An. fluviatilis even after 20 washings. The median knock-down time for these species ranged between 4.55-6.00 and 4.45-5.45 min, respectively, during 1 yr of intervention. In the Olyset net study area, there was a significant reduction of 80.6, 94.1, and 76.7% in the entry rate of An. culicifacies, An. fluviatilis, and other anopheline species, respectively, with an overall reduction of 63.5% in total mosquitoes. Floor sheet collections in houses with Olyset nets indicated 39% immediate mortality in total mosquitoes. The overall feeding success rate of mosquitoes in the trial village was only 18.0% in comparison to 44.2 and 79.1% in villages with untreated nets and no nets, respectively. A significant reduction was also recorded in parity rate and human blood index of vector species in the Olyset net area. This study showed that Olyset nets are an effective personal protection tool that can be used in a community-based intervention program.


Asunto(s)
Anopheles , Insectos Vectores , Control de Mosquitos/instrumentación , Animales , Conducta Alimentaria , India/epidemiología , Mordeduras y Picaduras de Insectos/epidemiología , Lavandería/estadística & datos numéricos , Malaria/transmisión , Oviparidad , Densidad de Población
20.
Indian J Med Res ; 130(4): 458-66, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19942752

RESUMEN

BACKGROUND & OBJECTIVES: Insecticide incorporated plastic sheeting is a new technology to control mosquitoes in emergency shelter places and also temporary habitations in different locations. Therefore, field studies were conducted to assess the efficacy of ZeroFly plastic sheeting treated with deltamethrin on prevailing disease vectors Anopheles culicifacies and An. fluviatilis and its impact on malaria transmission in one of the highly endemic areas of Orissa. METHODS: The study was conducted in Birkera block of Sundargarh district, Orissa state. The study area comprised 3 villages, which were randomized as ZeroFly plastic sheet, untreated plastic sheet and no sheet area. ZeroFly plastic sheets and untreated plastic sheets were fixed in study and control villages respectively covering all the rooms in each household. Longitudinal studies were conducted on the bioefficacy with the help of cone bioassays, monitoring of the mosquito density through hand catch, floor sheet and exit trap collections and fortnightly domiciliary active surveillance in all the study villages. RESULTS: In ZeroFly plastic sheeting area, there was a significant reduction of 84.7 per cent in the entry rate of total mosquitoes in comparison to pre-intervention phase. There was 56.2 per cent immediate mortality in total mosquitoes in houses with ZeroFly sheeting. The overall feeding success rate of mosquitoes in the trial village was only 12.5 per cent in comparison to 49.7 and 51.1 per cent in villages with untreated plastic sheet and no sheet respectively. There was a significant reduction of 65.0 and 70.5 per cent in malaria incidence in ZeroFly plastic sheeting area as compared to untreated plastic sheet and no sheet area respectively. INTERPRETATION & CONCLUSIONS: Our study showed that introduction of ZeroFly plastic sheets in a community-based intervention programme is operationally feasible to contain malaria especially in the high transmission difficult areas.


Asunto(s)
Ropa de Cama y Ropa Blanca , Insecticidas , Malaria , Control de Mosquitos/instrumentación , Plásticos/química , Equipos de Seguridad , Animales , Anopheles/efectos de los fármacos , Humanos , India , Insectos Vectores/efectos de los fármacos , Insecticidas/química , Insecticidas/farmacología , Malaria/prevención & control , Malaria/transmisión , Control de Mosquitos/métodos , Nitrilos/química , Nitrilos/farmacología , Piretrinas/química , Piretrinas/farmacología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA