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1.
Curr Microbiol ; 79(3): 85, 2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35129690

RESUMO

Production of fuels from renewable resources is of utmost importance due to fast depletion of fossil resources and related environmental issues. The present study explored the intrinsic capability of microbial strains to produce alka(e)nes, the next-generation biofuel, thus to reduce the dependence upon current petroleum fuels. Eight bacterial strains, namely, SDK-1, SDK-2, SDK-6, SDK-7, SDK-8, SDK-9, SDK-10, and SDK-11 were isolated from sludge and soil samples collected from different sources using lauric acid as a substrate with a potential to produce alka(e)nes. Production of different medium- and long-chain alka(e)nes by these isolates was confirmed via gas chromatography-mass spectrometer (GC-MS) analysis. SDK-1 (7.2%), SDK-2 (3.72%), and SDK-6 (3.52%) produced significant proportion of medium-chain hydrocarbons as compared to SDK-10 and control with no production. These isolates may be further investigated for production of these alternative sources of energy. In contrary, maximum fraction of long-chain hydrocarbons is produced in SDK-8 (75.28%) followed by SDK-9 (61.51%). Similarly more than 50% of the total hydrocarbons produced in SDK-8 constitute fossil mimic hydrocarbons while only 10.78% fractions were found in SDK-10. Since these fractions resemble different hydrocarbons obtained from crude oil, hence may be explored for their wide applications in different fields. Biochemical characterization and sequencing of the 16S rRNA gene revealed the homology of SDK-1, SDK-2 and SDK-6 with Pseudomonas aeruginosa, SDK-7 and SDK-9 with Enterobacter cloacae, SDK-8 with Klebsiella pnuemoniae, SDK-10 with Enterobacter hormaechei and SDK-11 with Pseudomonas nitroreducens, respectively.


Assuntos
Biocombustíveis , Petróleo , Bactérias/genética , Biodegradação Ambiental , Hidrocarbonetos , RNA Ribossômico 16S/genética
2.
Analyst ; 144(2): 567-572, 2019 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-30426975

RESUMO

Detection of lead has continued to be of immense interest in the present industrial as well as environmental diaspora. To this end, we report a prudent Schiff base which enables the sensitive detection of Pb2+ ions in mixed aqueous medium. The probe is afforded by simple synthetic and purification processes. Further, the probe employs simple mechanistic detection of Pb2+ and also successively detects a host of biothiols. The sensor is also used to detect Pb2+ ions in real water samples and consecutive detection of a variety of biothiols, including functionalized thiouracils, in onion and garlic extract. The fact that the Pb2+-L ensemble is 'non-selective' towards any particular thiol substituted analyte in real samples could as well prove to be an interesting contribution for chemical and biological detoxification processes.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38700831

RESUMO

Lipases are industrially important enzymes having vast applications in various fields. Cloning and expression of lipase enzyme-encoding genes in suitable host lead to their widespread use in different fields. The present study represents the first attempt towards the expression of the synthetic lipase gene in Pseudomonas aeruginosa. An alkalophilic lipase gene (GenBank accession number: NP_388152) from Bacillus subtilis was synthetically designed and introduced in the pJN105 vector and subsequently cloned in Pseudomonas aeruginosa SDK-6. Agarose gel electrophoresis confirmed the transformation of SDK-6, exhibiting a band difference of ~ 700 bp between native and recombinant pJN105. Further amplification of cloned lipase gene was confirmed using PCR amplification with Lip 1 and Lip 2 primers respectively, followed by restriction analysis. Approximately 15-fold increase in lipase production was observed in recombinant Pseudomonas as compared to the native strain. One factor at a time (OFAT) analysis revealed L-arabinose, inoculum size (0.5%; v/v), and agitation (120 rpm) as significant factors affecting the over-expression of lipase enzyme. Optimization of enzyme induction conditions by central composite design (CCD) led to 1.60-fold increase in the production of lipase at 0.65% (w/v) inducer concentration, OD600-1.075 before induction and 35 °C post induction temperature with overall lipase production of 50.50 IU/mL. Statistical validation of observed value via ANOVA showed an F-value of 138.70 at p < 0.01 with R2 of 0.9921.

5.
Sci Rep ; 14(1): 5753, 2024 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459096

RESUMO

Parasitic organisms pose a major global health threat, mainly in regions that lack advanced medical facilities. Early and accurate detection of parasitic organisms is vital to saving lives. Deep learning models have uplifted the medical sector by providing promising results in diagnosing, detecting, and classifying diseases. This paper explores the role of deep learning techniques in detecting and classifying various parasitic organisms. The research works on a dataset consisting of 34,298 samples of parasites such as Toxoplasma Gondii, Trypanosome, Plasmodium, Leishmania, Babesia, and Trichomonad along with host cells like red blood cells and white blood cells. These images are initially converted from RGB to grayscale followed by the computation of morphological features such as perimeter, height, area, and width. Later, Otsu thresholding and watershed techniques are applied to differentiate foreground from background and create markers on the images for the identification of regions of interest. Deep transfer learning models such as VGG19, InceptionV3, ResNet50V2, ResNet152V2, EfficientNetB3, EfficientNetB0, MobileNetV2, Xception, DenseNet169, and a hybrid model, InceptionResNetV2, are employed. The parameters of these models are fine-tuned using three optimizers: SGD, RMSprop, and Adam. Experimental results reveal that when RMSprop is applied, VGG19, InceptionV3, and EfficientNetB0 achieve the highest accuracy of 99.1% with a loss of 0.09. Similarly, using the SGD optimizer, InceptionV3 performs exceptionally well, achieving the highest accuracy of 99.91% with a loss of 0.98. Finally, applying the Adam optimizer, InceptionResNetV2 excels, achieving the highest accuracy of 99.96% with a loss of 0.13, outperforming other optimizers. The findings of this research signify that using deep learning models coupled with image processing methods generates a highly accurate and efficient way to detect and classify parasitic organisms.


Assuntos
Babesia , Aprendizado Profundo , Parasitos , Toxoplasma , Animais , Microscopia
6.
J Anaesthesiol Clin Pharmacol ; 29(4): 478-84, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24249984

RESUMO

BACKGROUND: The aim of preemptive analgesia is to reduce central sensitization that arises from noxious inputs across the entire perioperative period. N-methyl d-aspartate receptor antagonists have the potential for attenuating central sensitization and preventing central neuroplasticity. MATERIALS AND METHODS: Patients undergoing laparoscopic cholecystectomy were randomized into four groups of 20 patients each, who were administered the study drug intravenously 30 min before incision. Groups A, B, and C received ketamine in a dose of 1.00, 0.75 and 0.50 mg/kg, respectively, whereas group D received isotonic saline. Anesthetic and surgical techniques were standardized. Postoperatively, the degree of pain at rest, movement, and deep breathing using visual analogue scale, time of request for first analgesic, total opioid consumption, and postoperative nausea and vomiting were recorded in postanesthesia care unit for 24 h. RESULTS: Pain scores were highest in Group D at 0 h. Groups A, B, and C had significantly decreased postoperative pain scores at 0, 0.5, 3, 4, 5, 6, and 12 h. Postoperative analgesic consumption was significantly less in groups A, B, and C as compared with group D. There was no significant difference in the pain scores among groups A, B, and C. Group A had a significantly higher heart rate and blood pressure than groups B and C at 0 and 0.5 h along with 10% incidence of hallucinations. CONCLUSION: Preemptive ketamine has a definitive role in reducing postoperative pain and analgesic requirement in patients undergoing laparoscopic cholecystectomy. The lower dose of 0.5 mg/kg being devoid of any adverse effects and hemodynamic changes is an optimal dose for preemptive analgesia in patients undergoing laparoscopic cholecystectomy.

7.
Proc Inst Mech Eng H ; 237(4): 517-526, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36882980

RESUMO

For various orthopedic needs, several studies have been testified on non-absorbable implants, prepared with different metals/alloys, and composites. But yet little has been stated on the partially absorbable smart implants of thermoplastic composites for online health monitoring of veterinary patients. This article highlights the in-house development of affordable, polyvinylidene fluoride (PVDF) composite-based partially absorbable smart implants (with online sensing capability) for orthopedic needs in canines. Hydroxyapatite (HAp) and chitosan (CS) nanoparticles were reinforced in the PVDF matrix by a melt processing route with various weight proportions (wt.%) to fabricate a partially absorbable smart implant for the canine. The study suggests that the 8.0 wt.% HAp and 2.0 wt.% CS in PVDF is the superlative composition/proportion of reinforcement for preparing feedstock stock filaments (for 3D printing of partially absorbable smart implants), based on rheological, mechanical, thermal, dielectric, and voltage-current-resistance (V-I-R) characteristics. For the selected composition/proportion of PVDF composite, acceptable mechanical properties (such as modulus of toughness (MoT) 2.0 MPa, Young's modulus (E) 889 MPa), and dielectric properties (dielectric constant (εr) 9.6 at room temperature (30°C) and 20 MHz) for online sensing capabilities (for health monitoring) was observed. The results are braced by attenuated total reflection Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analysis.


Assuntos
Quitosana , Durapatita , Animais , Cães , Espectroscopia de Infravermelho com Transformada de Fourier , Durapatita/química , Polivinil , Quitosana/química
8.
J Biol Chem ; 286(42): 36787-807, 2011 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-21849498

RESUMO

Mammalian testis-determining factor SRY contains a high mobility group box, a conserved eukaryotic motif of DNA bending. Mutations in SRY cause XY gonadal dysgenesis and somatic sex reversal. Although such mutations usually arise de novo in spermatogenesis, some are inherited and so specify male development in one genetic background (the father) but not another (the daughter). Here, we describe the biophysical properties of a representative inherited mutation, V60L, within the minor wing of the L-shaped domain (box position 5). Although the stability and DNA binding properties of the mutant domain are similar to those of wild type, studies of SRY-induced DNA bending by subnanosecond time-resolved fluorescence resonance energy transfer (FRET) revealed enhanced conformational fluctuations leading to long range variation in bend angle. (1)H NMR studies of the variant protein-DNA complex demonstrated only local perturbations near the mutation site. Because the minor wing of SRY folds on DNA binding, the inherited mutation presumably hinders induced fit. Stopped-flow FRET studies indicated that such frustrated packing leads to accelerated dissociation of the bent complex. Studies of SRY-directed transcriptional regulation in an embryonic gonadal cell line demonstrated partial activation of downstream target Sox9. Our results have demonstrated a nonlocal coupling between DNA-directed protein folding and protein-directed DNA bending. Perturbation of this coupling is associated with a genetic switch poised at the threshold of activity.


Assuntos
Substituição de Aminoácidos , DNA/química , Disgenesia Gonadal 46 XY , Mutação de Sentido Incorreto , Conformação de Ácido Nucleico , Dobramento de Proteína , Proteína da Região Y Determinante do Sexo/química , Animais , Linhagem Celular , DNA/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Estrutura Terciária de Proteína , Roedores , Fatores de Transcrição SOX9/química , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Proteína da Região Y Determinante do Sexo/genética , Proteína da Região Y Determinante do Sexo/metabolismo , Relação Estrutura-Atividade , Transcrição Gênica/genética
9.
Proc Inst Mech Eng H ; 236(8): 1057-1069, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35592933

RESUMO

Some studies have been reported in the recent past on smart sensors for non-enzymatic glucose sensing applications. Nevertheless, little has been reported on the in-house development of low-cost 3D printed smart biomedical sensors with tunable sensitivity. This study reports investigations on the in-house, low-cost fabrication of polyvinyl difluoride (PVDF) matrix-based 3D printed tunable non-enzymatic glucose sensors. For fabrication of smart sensors, Cu (4%) doped ZnO nanoparticles have been reinforced (in different weight proportions (wt%) in PVDF matrix through melt processing. The results suggest that 4% reinforcement (of 4% Cu doped-ZnO), processed at 190°C, 40 rpm screw speed on twin screw extrusion (TSE) followed by post heat treatment (HT) at 60°C are the best settings for fabrication of feedstock filaments (for bio-sensor 3D printing). Finally, a PVDF-based sensor to support bioreceptor and transducer requirements has been successfully prepared (with 4D properties (i.e. one-way programing feature), optical, morphological, bond strength, piezoelectric and mechanical characteristics). The 3D printed electro-active sensor, (of selected composition) resulted in acceptable mechanical, piezoelectric, and dielectric properties (modulus of toughness (MoT) 1.46 MPa, Young's modulus (YM) 1221.7 MPa, piezoelectric coefficient 19.3pC/N and dielectric constant 6.5). The results have been supported by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), current-voltage-resistance (I-V-R), and Fourier transformed infrared (FTIR) analysis.


Assuntos
Óxido de Zinco , Glucose , Microscopia Eletrônica de Varredura , Impressão Tridimensional , Óxido de Zinco/química
10.
Insect Sci ; 29(5): 1309-1317, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35020973

RESUMO

Infections by mosquito-borne diseases represent one of the leading causes of death in third world countries. The rapid progression of resistance to conventional insecticide causes a significant threat to the highly efficient preventive methods currently in place. Insect neuropeptidergic system offers potential targets to control the insect vectors. The essential roles of the neuropeptide ecdysis triggering hormone (ETH) in insect development and reproduction led us to attempt understanding of the fundamentals of the biochemical interaction between ETH and its receptor in the African malaria mosquito Anopheles gambiae. One of two ETH peptides of the African malaria mosquito (AgETH1), a small peptide hormone with 17 amino acid residues (SESPGFFIKLSKSVPRI-NH2 ), was studied to elucidate its molecular structure. N-termini deletions and mutations of conserved amino acids in the ligand revealed the critical residues for the receptor activation. The solution structure of AgETH1 using 2D 1 H-1 H nuclear magnetic resonance (NMR) spectroscopy and nuclear overhauser effect (NOE) derived constraints revealed a short alpha helix between residues 3S and 11S. The NMR solution structure of AgETH1 will be of significant assistance for designing a new class of insecticidal compounds that acts on the AgETH receptor aiming for in silico docking studies.


Assuntos
Anopheles , Inseticidas , Malária , Neuropeptídeos , Hormônios Peptídicos , Aminoácidos/farmacologia , Animais , Anopheles/genética , Hormônios/farmacologia , Insetos , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Ligantes , Muda/genética , Controle de Mosquitos/métodos , Mosquitos Vetores/genética , Hormônios Peptídicos/farmacologia
11.
Prog Addit Manuf ; 7(5): 1023-1036, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-38624980

RESUMO

Despite numerous advantages of fused deposition modeling (FDM), the inherent layer-by-layer deposition behavior leads to considerable surface roughness and dimensional variability, limiting its usability for critical applications. This study has been conducted to select optimum parameters of FDM and vapour smoothing (chemical finishing) process to maximize surface finish, hardness, and dimensional accuracy. A self-adaptive cuckoo search algorithm for predictive modelling of surface and dimensional features of vapour-smoothened FDM-printed functional prototypes has been demonstrated. The chemical finishing has been performed on hip prosthesis (benchmark) using hot vapours of acetone (using dedicated experimental set-up). Based upon the selected design of experiment technique, 18 sets of experiments (with three repetitions) were performed by varying six parameters. Afterwards, a self-adaptive cuckoo search algorithm was implemented by formulating five objective functions using regression analysis to select optimum parameters. An excellent functional relationship between output and input parameters has been developed using a self-adaptive cuckoo search algorithm which has successfully found the solution to optimization issues related to different responses. The confirmatory experiments indicated a strong correlation between predicted and actual surface finish measurements, along with hardness and dimensional accuracy.

12.
PLoS One ; 17(4): e0266482, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35363829

RESUMO

The periodic breakdowns of stripe rust resistance due to emergence of new virulent and more aggressive pathotypes of Puccinia striiformis f. sp. tritici have resulted in severe epidemics in India. This necessitates the search for new and more durable resistance sources against stripe rust. The three bread wheat cultivars PBW 343 (carries Yr9 and Yr27), PBW 621 (carries Yr17) and HD 2967 (gene not known) were highly popular among the farmers after their release in 2011. But presently all three cultivars are highly susceptible to stripe rust at seedling as well as at adult plant stages as their resistance has been broken down due to emergence of new pathotypes of the pathogen (110S119, 238S119). In previous study, the crosses of PBW 621 with PBW 343 and HD 2967 and evaluation of further generations (up to F4) against pathotype 78S84 resulted in resistant segregants. In the present study, the F5 and F6 RIL populations have been evaluated against new pathotypes of Pst. The RILs categorized based on the disease severity on the P (Penultimate leaf) and F (flag) leaf into three categories i.e., high, moderate and low level of APR (adult plant resistance) having 1-200, 201-400 and >400 values of AUDPC, respectively, upon infection with stripe rust. The various APR components (latent period, lesion growth rate, spore production and uredial density) were studied on each category, i.e., resistant, moderately resistant and susceptible. The values of APR parameters decreased as the level of resistance increased. Based on molecular analysis, the lines (representing different categories of cross PBW 621 X PBW 343) containing the genes Yr9 and Yr17 due to their interactive effect provide resistance. Based on BSA using 35k SNPs and KASP markers association with phenotypic data of the RIL population (PBW 621 X HD 2967) showed the presence of two QTLs (Q.Pst.pau-6B, Q.Pst.pau-5B) responsible for the residual resistance and two SNPs AX-94891670 and AX-94454107 were found to be associated with the trait of interest on chromosome 6B and 5B respectively. The present study concludes that in the population of both the crosses (PBW 621 X PBW 343 and PBW 621 X HD 2967) major defeated gene contributed towards residual resistance by interacting with minor gene/QTLs.


Assuntos
Basidiomycota , Triticum , Pão , Resistência à Doença/genética , Marcadores Genéticos , Doenças das Plantas/genética , Puccinia , Triticum/genética
13.
Sci Rep ; 12(1): 17263, 2022 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-36241660

RESUMO

The devastating Varroa mite (Varroa destructor Anderson and Trueman) is an obligatory ectoparasite of the honey bee, contributing to significant colony losses in North America and throughout the world. The limited number of conventional acaricides to reduce Varroa mites and prevent disease in honey bee colonies is challenged with wide-spread resistance and low target-site selectivity. Here, we propose a biorational approach using comparative genomics for the development of honey bee-safe and selective acaricides targeting the Varroa mite-specific neuropeptidergic system regulated by proctolin, which is lacking in the honey bee. Proctolin is a highly conserved pentapeptide RYLPT (Arg-Tyr-Leu-Pro-Thr) known to act through a G protein-coupled receptor to elicit myotropic activity in arthropod species. A total of 33 different peptidomimetic and peptide variants were tested on the Varroa mite proctolin receptor. Ligand docking model and mutagenesis studies revealed the importance of the core aromatic residue Tyr2 in the proctolin ligand. Peptidomimetics were observed to have significant oral toxicity leading to the paralysis and death of Varroa mites, while there were no negative effects observed for honey bees. We have demonstrated that a taxon-specific physiological target identified by advanced genomics information offers an opportunity to develop Varroa mite-selective acaricides, hence, expedited translational processes.


Assuntos
Acaricidas , Peptidomiméticos , Varroidae , Acaricidas/farmacologia , Animais , Abelhas/genética , Genômica , Ligantes , Peptidomiméticos/farmacologia , Varroidae/fisiologia
14.
Adv Physiol Educ ; 35(4): 427-37, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22139782

RESUMO

As part of a 3-wk intersession workshop funded by a National Science Foundation Expeditions in Computing award, 15 undergraduate students from the City University of New York(1) collaborated on a study aimed at characterizing the voltage dynamics and arrhythmogenic behavior of cardiac cells for a broad range of physiologically relevant conditions using an in silico model. The primary goal of the workshop was to cultivate student interest in computational modeling and analysis of complex systems by introducing them through lectures and laboratory activities to current research in cardiac modeling and by engaging them in a hands-on research experience. The success of the workshop lay in the exposure of the students to active researchers and experts in their fields, the use of hands-on activities to communicate important concepts, active engagement of the students in research, and explanations of the significance of results as the students generated them. The workshop content addressed how spiral waves of electrical activity are initiated in the heart and how different parameter values affect the dynamics of these reentrant waves. Spiral waves are clinically associated with tachycardia, when the waves remain stable, and with fibrillation, when the waves exhibit breakup. All in silico experiments were conducted by simulating a mathematical model of cardiac cells on graphics processing units instead of the standard central processing units of desktop computers. This approach decreased the run time for each simulation to almost real time, thereby allowing the students to quickly analyze and characterize the simulated arrhythmias. Results from these simulations, as well as some of the background and methodology taught during the workshop, is presented in this article along with the programming code and the explanations of simulation results in an effort to allow other teachers and students to perform their own demonstrations, simulations, and studies.


Assuntos
Arritmias Cardíacas/fisiopatologia , Gráficos por Computador , Simulação por Computador , Técnicas Eletrofisiológicas Cardíacas , Sistema de Condução Cardíaco/fisiopatologia , Modelos Cardiovasculares , Fisiologia/educação , Ensino/métodos , Arritmias Cardíacas/diagnóstico , Compreensão , Processamento Eletrônico de Dados , Retroalimentação , Humanos , Aprendizagem , Inquéritos e Questionários , Fatores de Tempo
15.
Compr Rev Food Sci Food Saf ; 9(4): 398-416, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33467837

RESUMO

Ripening of fleshy fruit is a differentiation process involving biochemical and biophysical changes that lead to the accumulation of sugars and subsequent changes in tissue texture. Also affected are phenolic compounds, which confer color, flavor/aroma, and resistance to pathogen invasion and adverse environmental conditions. These phenolic compounds, which are the products of branches of the phenylpropanoid pathway, appear to be closely linked to fruit ripening processes. Three key enzymes of the phenylpropanoid pathway, namely phenylalanine ammonia lyase, O-methyltransferase, and cinnamyl alcohol dehydrogenase (CAD) have been reported to modulate various end products including lignin and protect plants against adverse conditions. In addition, peroxidase, the enzyme following CAD in the phenylpropanoid pathway, has also been associated with injury, wound repair, and disease resistance. However, the role of these enzymes in fruit ripening is a matter of only recent investigation and information is lacking on the relationships between phenylpropanoid metabolism and fruit ripening processes. Understanding the role of these enzymes in fruit ripening and their manipulation may possibly be valuable for delineating the regulatory network that controls the expression of ripening genes in fruit. This review elucidates the functional characterization of these key phenylpropanoid biosynthetic enzymes/genes during fruit ripening processes.

16.
Mol Cell Biol ; 26(2): 535-47, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16382145

RESUMO

Doublesex (dsx) is a transcription factor in Drosophila that regulates somatic sexual differentiation. Male- and female-specific splicing isoforms of DSX share a novel DNA-binding domain, designated the DM motif. Broadly conserved among metazoan sex-determining factors, the DM domain contains a nonclassical zinc module and binds in the DNA minor groove. Here, we characterize the DM motif by site-directed and random mutagenesis using a yeast one-hybrid (Y1H) system and extend this analysis by chemogenetic complementation in vitro. The Y1H system is based on a sex-specific Drosophila enhancer element and validated through studies of intersexual dsx mutations. We demonstrate that the eight motif-specific histidines and cysteines engaged in zinc coordination are each critical and cannot be interchanged; folding also requires conserved aliphatic side chains in the hydrophobic core. Mutations that impair DNA binding tend to occur at conserved positions, whereas neutral substitutions occur at nonconserved sites. Evidence for a specific salt bridge between a conserved lysine and the DNA backbone is obtained through the synthesis of nonstandard protein and DNA analogs. Together, these results provide molecular links between the structure of the DM domain and its function in the regulation of sexual dimorphism.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/fisiologia , Processamento Alternativo , Sequência de Aminoácidos , Animais , Cisteína/genética , Proteínas de Ligação a DNA/fisiologia , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/genética , Elementos Facilitadores Genéticos , Feminino , Histidina/genética , Masculino , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese , Dobramento de Proteína , Estrutura Terciária de Proteína , Homologia de Sequência de Aminoácidos , Caracteres Sexuais , Zinco/química
17.
Chem Asian J ; 14(24): 4625-4630, 2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31237099

RESUMO

Luminescent detection of heavy metals continues to be of growing importance considering their increasing inseparable roles in modern day lifestyle. To this end, we report a simple yet interesting thiourea derivative that results in detection of CuII in a turn-on fashion via a chemodosimetric redox reaction leading to oxidative cyclization of the chemosensor molecule. Elaborate studies with regard to the sensing process have been performed along with the proposal of a plausible cyclization mechanism of the molecule. Furthermore, the probe optically detects HgII , yet another heavy metal of prime importance, discernable even to the naked eye. The occurrence of a coordination complex has been proved by UV/Visible spectroscopic experiments as well as ESI-mass spectrometry.

18.
Proc Inst Mech Eng H ; 233(7): 754-760, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31132941

RESUMO

Poly lactic acid reinforced with hydroxyapatite and chitosan is one of the commonly used thermoplastic composite materials in three-dimensional printing of orthopaedic scaffolds. This article is an extension of work reported on hydroxyapatite- and chitosan-reinforced, poly lactic acid-based biocompatible feedstock filament for three-dimensional printing of functional prototypes on low cost commercial fused deposition modelling setup. In this work, joining of orthopaedic scaffolds has been performed with rapid tooling by using friction stir welding process. Finally, the mechanical properties (such as tensile strength and hardness) of the orthopaedic scaffolds joints were studied with support of the photomicrographs and thermal images. The results of study suggest that best settings for joining of micro cracks in orthopaedic scaffolds of poly lactic acid-hydroxyapatite-chitosan are rotational speed of 1000 r/min with length of consumable tool as 4 mm and staring time as 40 s.


Assuntos
Procedimentos Ortopédicos/métodos , Alicerces Teciduais/química , Materiais Biocompatíveis/química , Quitosana/química , Durapatita/química , Fricção , Dureza , Teste de Materiais , Poliésteres/química , Impressão Tridimensional , Temperatura , Resistência à Tração , Engenharia Tecidual
19.
Proc Inst Mech Eng H ; 233(11): 1196-1203, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31545132

RESUMO

In this experimental study, a composite of poly-ether-ketone-ketone by reinforcement of hydroxyapatite and chitosan has been prepared for possible applications as orthopaedic scaffolds. Initially, different weight percentages of hydroxyapatite and chitosan were reinforced in the poly-ether-ketone-ketone matrix and tested for melt flow index in order to check the flowability of different compositions/proportions. Suitable compositions revealed by the melt flow index test were then taken forward for the extrusion of filament required for fused deposition modelling. For thermomechanical investigations, Taguchi-based design of experiments has been used with input variables in the extrusion process as follows: temperature, load applied and different composition/proportions. The specimens in the form of feedstock filament produced by the extrusion process were made to undergo tensile testing. The specimens were also inspected by differential scanning calorimetry and photomicrographs. Finally, the specimen showing the best performance from the thermomechanical viewpoint has been selected to extrude the filament for the fused deposition modelling process.


Assuntos
Benzofenonas/química , Quitosana/química , Durapatita/química , Teste de Materiais , Fenômenos Mecânicos , Polímeros/química , Temperatura , Procedimentos Ortopédicos , Alicerces Teciduais/química
20.
Polymers (Basel) ; 11(1)2019 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-30960046

RESUMO

This paper highlights the multi-material additive manufacturing (AM) route for manufacturing of innovative materials and structures. Three different recycled thermoplastics, namely acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), and high impact polystyrene (HIPS) (with different Young's modulus, glass transition temperature, rheological properties), have been selected (as a case study) for multi-material AM. The functional prototypes have been printed on fused deposition modelling (FDM) setup as tensile specimens (as per ASTM D638 type-IV standard) with different combinations of top, middle, and bottom layers (of ABS/PLA/HIPS), at different printing speed and infill percentage density. The specimens were subjected to thermal (glass transition temperature and heat capacity) and mechanical testing (peak load, peak strength, peak elongation, percentage elongation at peak, and Young's modulus) to ascertain their suitability in load-bearing structures, and the fabrication of functional prototypes of mechanical meta-materials. The results have been supported by photomicrographs to observe the microstructure of the analyzed multi-materials.

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