Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 166
Filtrar
1.
Spat Stat ; 49: 100537, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34493969

RESUMO

At the very outbreak of a pandemic, it is very important to be able to assess the spreading rate of the disease i.e., the rate of increase of infected people in a specific locality. Combating the pandemic situation critically depends on an early and correct prediction of, to what extent the disease may possibly grow within a short period of time. This paper attempts to estimate the spreading rate by counting the total number of infected persons at times. Adaptive clustering is especially suitable for forming clusters of infected persons distributed spatially in a locality and successive sampling is used to measure the growth in number of infected persons. We have formulated a 'chain ratio to regression type estimator of population total' in two occasions adaptive cluster successive sampling and studied the properties of the estimator. The efficacy of the proposed strategy is demonstrated through simulation technique as well as real life population which is followed by suitable recommendation.

3.
Public Health ; 189: 37-47, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33147524

RESUMO

OBJECTIVES: Adverse childhood experiences (ACEs) have a negative impact on childhood health, but their impact on education outcomes is less well known. We investigated whether or not ACEs were associated with reduced educational attainment at age 7 and 11 years. STUDY DESIGN: The study design used in the study is a population-based electronic cohort study. METHODS: We analysed data from a total population electronic child cohort in Wales, UK. ACEs (exposures) were living with an adult household member with any of (i) serious mental illness, (ii) common mental disorder (CMD), (iii) an alcohol problem; (iv) child victimisation, (v) death of a household member and (vi) low family income. We used multilevel logistic regression to model exposure to these ACEs and not attaining the expected level at statutory education assessments, Key Stage (KS) 1 and KS2 separately, adjusted for known confounders including perinatal, socio-economic and school factors. RESULTS: There were 107,479 and 43,648 children included in the analysis, with follow-up to 6-7 years (KS1) and 10-11 years (KS2), respectively. An increased risk of not attaining the expected level at KS1 was associated with living with adult household members with CMD (adjusted odds ratio [aOR]: 1.13 [95% confidence interval [CI]: 1.09-1.17]) or an alcohol problem (adjusted odds ratio [aOR]: 1.16 [95% confidence interval [CI]: 1.10-1.22]), childhood victimisation (adjusted odds ratio [aOR]: 1.58 [95% confidence interval [CI]: 1.37-1.82]), death of a household member (adjusted odds ratio [aOR]: 1.14 [95% confidence interval [CI]: 1.04-1.25]) and low family income (adjusted odds ratio [aOR]: 1.92 [95% confidence interval [CI]: 1.84-2.01]). Similar results were observed for KS2. Children with multiple adversities had substantially increased odds of not attaining the expected level at each educational assessment. CONCLUSION: The educational potential of many children may not be achieved due to exposure to adversity in childhood. Affected children who come in to contact with services should have relevant information shared between health and care services, and schools to initiate and facilitate a coordinated approach towards providing additional support and help for them to fulfil their educational potential, and subsequent economic and social participation.


Assuntos
Sucesso Acadêmico , Experiências Adversas da Infância/estatística & dados numéricos , Escolaridade , Consumo de Bebidas Alcoólicas/epidemiologia , Criança , Pré-Escolar , Estudos de Coortes , Vítimas de Crime/estatística & dados numéricos , Feminino , Humanos , Renda/estatística & dados numéricos , Modelos Logísticos , Masculino , Transtornos Mentais/epidemiologia , Razão de Chances , Instituições Acadêmicas , Fatores Socioeconômicos , País de Gales
4.
Science ; 368(6489): 401-405, 2020 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-32193361

RESUMO

Although there have been no cases of serotype 2 wild poliovirus for more than 20 years, transmission of serotype 2 vaccine-derived poliovirus (VDPV2) and associated paralytic cases in several continents represent a threat to eradication. The withdrawal of the serotype 2 component of oral poliovirus vaccine (OPV2) was implemented in April 2016 to stop VDPV2 emergence and secure eradication of all serotype 2 poliovirus. Globally, children born after this date have limited immunity to prevent transmission. Using a statistical model, we estimated the emergence date and source of VDPV2s detected between May 2016 and November 2019. Outbreak response campaigns with monovalent OPV2 are the only available method to induce immunity to prevent transmission. Yet our analysis shows that using monovalent OPV2 is generating more paralytic VDPV2 outbreaks with the potential for establishing endemic transmission. A novel OPV2, for which two candidates are currently in clinical trials, is urgently required, together with a contingency strategy if this vaccine does not materialize or perform as anticipated.


Assuntos
Erradicação de Doenças/métodos , Surtos de Doenças/prevenção & controle , Saúde Global , Poliomielite/epidemiologia , Poliomielite/etiologia , Vacina Antipólio Oral/efeitos adversos , Poliovirus/imunologia , Humanos , Poliomielite/prevenção & controle , Poliomielite/transmissão , Suspensão de Tratamento
6.
PLoS One ; 12(9): e0183677, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28880876

RESUMO

A cable model that includes polarization-induced capacitive current is derived for modeling the solitonic conduction of electrotonic potentials in neuronal branchlets with microstructure containing endoplasmic membranes. A solution of the nonlinear cable equation modified for fissured intracellular medium with a source term representing charge 'soakage' is used to show how intracellular capacitive effects of bound electrical charges within mitochondrial membranes can influence electrotonic signals expressed as solitary waves. The elastic collision resulting from a head-on collision of two solitary waves results in localized and non-dispersing electrical solitons created by the nonlinearity of the source term. It has been shown that solitons in neurons with mitochondrial membrane and quasi-electrostatic interactions of charges held by the microstructure (i.e., charge 'soakage') have a slower velocity of propagation compared with solitons in neurons with microstructure, but without endoplasmic membranes. When the equilibrium potential is a small deviation from rest, the nonohmic conductance acts as a leaky channel and the solitons are small compared when the equilibrium potential is large and the outer mitochondrial membrane acts as an amplifier, boosting the amplitude of the endogenously generated solitons. These findings demonstrate a functional role of quasi-electrostatic interactions of bound electrical charges held by microstructure for sustaining solitons with robust self-regulation in their amplitude through changes in the mitochondrial membrane equilibrium potential. The implication of our results indicate that a phenomenological description of ionic current can be successfully modeled with displacement current in Maxwell's equations as a conduction process involving quasi-electrostatic interactions without the inclusion of diffusive current. This is the first study in which solitonic conduction of electrotonic potentials are generated by polarization-induced capacitive current in microstructure and nonohmic mitochondrial membrane current.


Assuntos
Potenciais de Ação/fisiologia , Potencial da Membrana Mitocondrial , Modelos Neurológicos , Neurônios/fisiologia , Membranas Mitocondriais/metabolismo
7.
ACS Appl Mater Interfaces ; 9(12): 10664-10672, 2017 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-28267317

RESUMO

Generation of hydrogen by photochemical, electrochemical, and other means is a vital area of research today, and a variety of materials have been explored as catalysts for this purpose. C3N4, MoS2, and nitrogenated RGO (NRGO) are some of the important catalytic materials investigated for the hydrogen evolution reaction (HER) reaction, but the observed catalytic activities are somewhat marginal. Prompted by preliminary reports that covalent cross-linking of 2D materials to generate heteroassemblies or nanocomposites may have beneficial effect on the catalytic activity, we have synthesized nanocomposites wherein C3N4 is covalently bonded to MoS2 or NRGO nanosheets. The photochemical HER activity of the C3N4-MoS2 nanocomposite is found to be remarkable with an activity of 12778 µmol h-1 g-1 and a turnover frequency of 2.35 h-1. The physical mixture of C3N4 and MoS2, on the other hand, does not exhibit notable catalytic activity. Encouraged by this result, we have studied electrochemical HER activity of these composites as well. C3N4-MoS2 shows superior activity relative to a physical mixture of MoS2 and C3N4. Density functional theory calculations have been carried out to understand the HER activity of the nanocomposites. Charge-transfer between the components and greater planarity of cross-linked layers are important causes of the superior catalytic activity of the nanocomposites. Covalent linking of such 2D materials appears to be a worthwhile strategy for catalysis and other applications.

8.
Indian J Tuberc ; 63(4): 242-244, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27998496

RESUMO

Tuberculosis (TB) is an infectious disease commonly caused by the bacillus mycobacterium and worldwide estimation demonstrated that more than 8.6 million people are infected by TB. Many of the previous studies reported the association between TB and ABO blood group polymorphism. In this context, the objective of the present study is to understand the association of ABO blood group polymorphism and TB in Bengalee Hindu caste population. The present study consists of 100 clinically diagnosed TB patients and 100 apparently healthy individuals with no previous history of TB from the same population of the same area. The distribution of ABO phenotypes demonstrated significant (p<0.05) excess of AB blood group in TB patients and significant (p<0.05) decrease of O blood group in controls. Logistic regression analysis revealed that individuals with non O blood group have 1.97 times (95% CI 1.04-3.75) greater chance of developing TB than individuals with O blood group.


Assuntos
Sistema ABO de Grupos Sanguíneos/genética , Polimorfismo Genético , Classe Social , Tuberculose/genética , Estudos de Casos e Controles , Humanos , Índia/epidemiologia , Fenótipo , Tuberculose/sangue , Tuberculose/epidemiologia
9.
Physiol Int ; 103(2): 191-201, 2016 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28639867

RESUMO

Rapid economic and industrial growths imposed significant impact on human health including the pulmonary health. Questions were raised regarding the validity of the existing prediction norms of pulmonary function tests (PFTs) in a particular population. The present study was conducted to investigate the applicability of the existing norms for PFTs in young healthy non-smoking female university students of Kolkata, India. Significant difference was noted in vital capacity (VC), forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV1) when the present data were compared with the earlier study in similar population. Correlation statistic revealed significant relationship of age and body height with all the PFT parameters. Body mass had significant correlation with VC, FVC, FEV1 as a percentage of FVC (FEV1%), and peak expiratory flow rate (PEFR). Regression equations have been computed for predicting PFTs from age and body height. There has been a change of PFTs in the studied population for the last couple of decades due to increased environmental pollution in the course of economical and industrial developments. Regression equations computed in this study are not only recommended to predict PFT parameters in the studied population, but they are also considered more reliable owing to their substantially smaller standard error of estimate than those proposed in the previous study.


Assuntos
Pulmão/fisiologia , Adulto , Fatores Etários , Feminino , Volume Expiratório Forçado/fisiologia , Humanos , Índia/epidemiologia , Pico do Fluxo Expiratório/fisiologia , Valores de Referência , Testes de Função Respiratória/normas , Estudantes/estatística & dados numéricos , Capacidade Vital/fisiologia , Adulto Jovem
10.
Cell Death Dis ; 6: e1873, 2015 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-26335715

RESUMO

Pathological cardiac hypertrophy is a major risk factor associated with heart failure, a state concomitant with increased cell death. However, the mechanism governing progression of hypertrophy to apoptosis at the single-cell level remains elusive. Here, we demonstrate annexin A6 (Anxa6), a calcium (Ca(2+))-dependent phospholipid-binding protein critically regulates the transition of chronic hypertrophied cardiomyocytes to apoptosis. Treatment of the H9c2(2-1) cardiomyocytes with hypertrophic agonists upregulates and relocalizes Anxa6 with increased cytosolic punctate appearance. Live cell imaging revealed that chronic exposure to hypertrophic agonists such as phenylephrine (PE) compromises the mitochondrial membrane potential (ΔΨm) and morphological dynamics. Such chronic hypertrophic induction also activated the caspases 9 and 3 and induced cleavage of the poly-(ADP-ribose) polymerase 1 (Parp1), which are the typical downstream events in the mitochondrial pathways of apoptosis. An increased rate of apoptosis was evident in the hypertrophied cardiomyocytes after 48-72 h of treatment with the hypertrophic agonists. Anxa6 was progressively associated with the mitochondrial fraction under chronic hypertrophic stimulation, and Anxa6 knockdown severely abrogated mitochondrial network and dynamics. Ectopically expressed Anxa6 protected the mitochondrial morphology and dynamics under PE treatment, and also increased the cellular susceptibility to apoptosis. Biochemical analysis showed that Anxa6 interacts with Parp1 and its 89 kDa cleaved product in a Ca(2+)-dependent manner through the N-terminal residues (1-28). Furthermore, expression of Anxa6(S13E), a mutant dominant negative with respect to Parp1 binding, served as an enhancer of mitochondrial dynamics, even under chronic PE treatment. Chemical inhibition of Parp1 activity released the cellular vulnerability to apoptosis in Anxa6-expressing stable cell lines, thereby shifting the equilibrium away from cell death. Taken together, the present study depicts a dual regulatory function of Anxa6 that is crucial for balancing hypertrophy with apoptosis in cardiomyocytes.


Assuntos
Anexina A6/metabolismo , Cardiomegalia/metabolismo , Insuficiência Cardíaca/etiologia , Miócitos Cardíacos/metabolismo , Apoptose , Cardiomegalia/patologia , Insuficiência Cardíaca/patologia
11.
Biol Sport ; 32(1): 59-63, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25729151

RESUMO

The present study was conducted to validate the applicability of Cooper's 12-minute run test (CRT) for predicting VO2max in male university students of Kolkata, India, to bypass the exhaustive and complicated protocol of direct estimation of VO2max. Eighty-eight sedentary male university students recruited by simple random sampling from the University of Calcutta, Kolkata, were randomly assigned to the study group (N = 58) and the confirmatory group (N = 30). VO2max of each participant was determined by the direct procedure and the indirect CRT method. The mean value of predicted VO2max (PVO2max) (42.8±4.0 ml · kg(-1) · min(-1) with a range of 33.7-50.9) showed a significant difference with VO2max (39.8±4.0 ml · kg(-1) · min(-1) with a range of 33.5-47.7) in the study group. Limits of agreement between PVO2max and VO2max were large enough (0.10 to 5.94 ml · kg(-1) · min(-1)) with poor confidence intervals indicating inapplicability of the current protocol of CRT in the studied population. The prediction norm [Y = 21.01X - 11.04 (SEE = 0.193 ml · kg(-1) · min(-1))] was computed from the significant correlation (r = 0.93, P < 0.001) between distance covered in CRT and VO2max. Application of this norm in the confirmatory group revealed an insignificant difference between PVO2max and VO2max. The modified equation is recommended for application of CRT as a valid method to evaluate the cardiorespiratory fitness in terms of VO2max in sedentary male Indian youth.

12.
Exp Appl Acarol ; 66(1): 159-71, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25717008

RESUMO

To develop an eco-friendly tick control method, seven plant extracts were prepared using 50 and 95% ethanol and evaluated for acaricidal activity against cattle tick, Rhipicephalus (Boophilus) microplus. The adult immersion test was adopted for testing different extracts. Based on 72 h screening criterion, 95% ethanolic extracts of Datura metel fruits and Argemone mexicana whole plant were found effective showing more than 50% mortality of treated ticks. The 95% ethanolic extracts of D. metel fruits and A. mexicana whole plant exhibited acaricidal and reproductive inhibitory effects on treated ticks. The LC90 values of D. metel and A. mexicana extracts were determined as 7.13 and 11.3%, respectively. However, although both the extracts were found efficacious against deltamethrin-resistant IVRI-4 and multi-acaricide resistant IVRI-5 lines of R. (B.) microplus, they caused less mortality than treated ticks of the reference IVRI-I line. Phytochemical studies indicated the presence of alkaloids and glucosides in D. metel fruits and alkaloids, terpenoids, flavonoids and phenolics in A. mexicana whole plant extracts. The results indicated that these botanicals may play an important role in reducing the use of chemicals for tick control and possibly to manage resistant tick population in environment friendly manner.


Assuntos
Magnoliopsida/química , Extratos Vegetais/farmacologia , Rhipicephalus/efeitos dos fármacos , Controle de Ácaros e Carrapatos/métodos , Acaricidas/farmacologia , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/prevenção & controle , Resistência a Medicamentos , Feminino , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle , Infestações por Carrapato/veterinária
14.
Oncogene ; 33(28): 3707-16, 2014 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-23975430

RESUMO

Tumor metastasis is the leading cause of death among breast cancer patients. PELP1 (proline, glutamic acid and leucine rich protein 1) is a nuclear receptor coregulator that is upregulated during breast cancer progression to metastasis and is an independent prognostic predictor of shorter survival of breast cancer patients. Here, we show that PELP1 modulates expression of metastasis-influencing microRNAs (miRs) to promote cancer metastasis. Whole genome miR array analysis using PELP1-overexpressing and PELP1-underexpressing model cells revealed that miR-200 and miR-141 levels inversely correlated with PELP1 expression. Consistent with this, PELP1 knockdown resulted in lower expression of miR-200a target genes ZEB1 and ZEB2. PELP1 knockdown significantly reduced tumor growth and metastasis compared with parental cells in an orthotopic xenograft tumor model. Furthermore, re-introduction of miR-200a and miR-141 mimetics into PELP1-overexpressing cells reversed PELP1 target gene expression, decreased PELP1-driven migration/invasion in vitro and significantly reduced in vivo metastatic potential in a preclinical model of experimental metastasis. Our results demonstrated that PELP1 binds to miR-200a and miR-141 promoters and regulates their expression by recruiting chromatin modifier histone deacetylase 2 (HDAC2) as revealed by chromatin immunoprecipitation, small interfering RNA and HDAC inhibitor assays. Taken together, our results suggest that PELP1 regulates tumor metastasis by controlling the expression and functions of the tumor metastasis suppressors miR-200a and miR-141.


Assuntos
Neoplasias da Mama/patologia , Proteínas Correpressoras/metabolismo , Transição Epitelial-Mesenquimal , Histona Desacetilase 2/metabolismo , MicroRNAs/metabolismo , Fatores de Transcrição/metabolismo , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Proteínas Correpressoras/genética , Epigênese Genética , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Camundongos Nus , MicroRNAs/genética , Metástase Neoplásica , Fatores de Transcrição/deficiência , Fatores de Transcrição/genética
15.
Infection ; 42(1): 165-70, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24243481

RESUMO

We examined heavy alcohol use as a risk factor for severe influenza (intensive care admission or death) among hospitalized adults. In <65- and ≥65-year-olds, heavy alcohol use increased disease severity [relative risk (RR) 1.34; 95 % confidence interval (CI): 1.04-1.74, and RR 2.47; 95 % CI: 1.69-3.60, respectively]. Influenza vaccination and early, empiric antiviral treatment should be emphasized in this population.


Assuntos
Alcoolismo/complicações , Influenza Humana/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto Jovem
16.
J Neonatal Perinatal Med ; 6(3): 251-6, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24246598

RESUMO

BACKGROUND: A recent multinational clinical trial in preterm infants has demonstrated pulmonary and neurodevelopmental benefits from caffeine therapy. Indications for caffeine use in that study were predominantly for treatment of apnea and facilitation of extubation rather than prophylaxis. There are no recent studies that describe current practice of neonatologists and regional differences in regards to indications for starting, monitoring and discontinuing methylxanthine therapy in premature infants. OBJECTIVE: To characterize the spectrum of current practice and demonstrate the extent to which methylxanthine therapy varies by location. METHODS: A cross-sectional survey of all neonatologists in Thailand, Lebanon, Australia, and a representative sample in the USA regarding management of apnea of prematurity. RESULTS: The response rate was 50% (342/681). The methylxanthine of choice varied greatly across study locations. Prophylactic methylxanthine use is common (62%) among neonatologists in all four study locations. Significant variation exists in almost all aspects of apnea pharmacotherapy practice among neonatologists in different international locations. CONCLUSIONS: Prophylactic use of methylxanthine therapy for apnea of prematurity is widespread. We speculate that this expanded use is possibly attributed to the beneficial effects of caffeine therapy in the Caffeine for Apnea of Prematurity (CAP) Trial.


Assuntos
Apneia/tratamento farmacológico , Cafeína/uso terapêutico , Doenças do Prematuro/tratamento farmacológico , Neonatologia/métodos , Xantinas/uso terapêutico , Austrália , Estudos Transversais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Líbano , Masculino , Inquéritos e Questionários , Tailândia , Estados Unidos
17.
Rev Sci Instrum ; 84(3): 033301, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23556809

RESUMO

Radioactive ion beams (RIB) have been produced on-line, using a gas-jet recoil transport coupled Electron Cyclotron Resonance (ECR) ion-source at the VECC-RIB facility. Radioactive atoms∕molecules carried through the gas-jet were stopped in a catcher placed inside the ECR plasma chamber. A skimmer has been used to remove bulk of the carrier gas at the ECR entrance. The diffusion of atoms∕molecules through the catcher has been verified off-line using stable isotopes and on-line through transmission of radioactive reaction products. Beams of (14)O (71 s), (42)K (12.4 h), (43)K (22.2 h), and (41)Ar (1.8 h) have been produced by bombarding nitrogen and argon gas targets with proton and alpha particle beams from the K130 cyclotron at VECC. Typical measured intensity of RIB at the separator focal plane is found to be a few times 10(3) particles per second (pps). About 3.2 × 10(3) pps of 1.4 MeV (14)O RIB has been measured after acceleration through a radiofrequency quadrupole linac. The details of the gas-jet coupled ECR ion-source and RIB production experiments are presented along with the plans for the future.

18.
Indian J Virol ; 24(1): 59-65, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24426259

RESUMO

A PCR based method for detection of viral DNA in nucleopolyhedrovirus of three lepidopterans, Spodoptera litura, Amsacta albistriga and Helicoverpa armigera, was developed by employing the late expression factor-8 (lef-8) gene of three NPV using specific primers. The amplicons of 689, 699 and 665 bp were amplified, respectively, and the nucleotide sequences were submitted to GenBank and the accession numbers were obtained. The sequences of lef-8 gene of S. litura NPV and H. armigera NPV matched with those of their respective references in the GenBank database, thereby confirming their identity, however, the sequence of A. albistriga NPV was the first sequence submitted to the GenBank database. The sequence similarity analysis between the three lef-8 gene of NPV sequenced in the present study revealed that there was no significant similarity between them, however A. albistriga NPV and S. litura NPV were found to be closely related. CLUSTAL alignment of the sequences generated revealed general relatedness among NPVs lef-8 gene. The study confirmed that lef-8 gene can be used for quick and correct discriminatory identification of insect viruses.

19.
Vet Comp Orthop Traumatol ; 25(4): 286-96, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22580779

RESUMO

OBJECTIVES: To design, manufacture and analyze custom implants with functional gradation in macrostructure for attachment of amputation prostheses. METHODS: The external shape of the implant was designed by extracting geometrical data of canine cadavers from computed tomography (CT) scans to suit the bone cavity. Three generations of implant designs were developed and were optimized with the help of fit/fill and mechanical performance of implant-cadaver bone assembly using CT analysis and compression testing, respectively. A final optimized, custom Ti6Al4V alloy amputation implant, with approximately 25% porosity in the proximal region and approximately zero percent porosity in the distal region, was fabricated using Laser Engineered Net Shaping (LENS™)--a laser based additive manufacturing technology. RESULTS: The proposed design changes in the second generation designs, in terms of refining thresholds, increased the average fill of the bone cavity from 58% to 83%. Addition of a flange between the stem and the head in the second generation designs resulted in more than a seven-fold increase in the compressive load carrying capacity of the assembly. Application of LENS™ in the fabrication of present custom fit Ti6Al4V alloy implants enabled incorporation of 20 to 30% porosity in the proximal region and one to two percent residual porosity in the distal portion of the implant. CLINICAL SIGNIFICANCE: Patient specific prostheses having direct connection to the skeletal structure can potentially aid in problems related to load transfer and proprioception in amputees. Furthermore, application of LENS™ in the fabrication of custom implants can be faster to incorporate site specific porosity and gradients for improving long-term stability.


Assuntos
Ligas/química , Doenças do Cão/cirurgia , Cães/cirurgia , Teste de Materiais/veterinária , Próteses e Implantes/veterinária , Titânio/química , Animais , Osso e Ossos , Cadáver , Estresse Mecânico , Suporte de Carga
20.
Nat Prod Res ; 26(16): 1519-22, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-21978132

RESUMO

Maesilea quadrifolia Linn. (Marsileaceae) is a leafy vegetable well known in India. The current study aims to explore the phytochemical profile of M. quadrifolia and investigate its anti-cholinesterase potential. The methanol extract of the plant was subjected to qualitative and quantitative phytochemical screening (total alkaloidal content, saponin content and phenol content) and its anti-cholinesterase potential was tested by TLC bioautography and other screening methods using acytylcholinesterase (AChE) and butyrylcholinesterase (BChE). The study revealed that the extract contains various classes of phytoconstituents including steroids, saponins, alkaloids and other polyphenols. Total alkaloid, phenolic and saponin contents were found to be 19.3 mg g⁻¹ and 158.5 ± 1.02 mg g⁻¹ as gallic acid equivalents and 2.63 mg g⁻¹ of the extract, respectively. The TLC bioautography method exhibited the inhibition of both enzymes. In a microtiter plate assay, the IC50 values of the extract for AChE and BChE were found to be 51.89 ± 0.24 µg mL⁻¹ and 109.43 ± 2.82 µg mL⁻¹, respectively. These findings suggest that M. quadrifolia is a potential lead as an AChE and BChE inhibitor, which may be useful in the management of Alzheimer's disease.


Assuntos
Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Marsileaceae/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/enzimologia , Acetilcolinesterase/metabolismo , Alcaloides/química , Butirilcolinesterase/metabolismo , Ativação Enzimática/efeitos dos fármacos , Índia , Polifenóis/química , Saponinas/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...