479 research outputs found

    An analytical and experimental study of the behavior of semi-infinite metal targets under hypervelocity impact

    Get PDF
    The material strength and strain rate effects associated with the hypervelocity impact problem were considered. A yield criterion involving the second and third invariants of the stress deviator and a strain rate sensitive constitutive equation were developed. The part of total deformation which represents change in shape is attributable to the stress deviator. Constitutive equation is a means for analytically describing the mechanical response of a continuum under study. The accuracy of the yield criterion was verified utilizing the published two and three dimensional experimental data. The constants associated with the constitutive equation were determined from one dimensional quasistatic and dynamic experiments. Hypervelocity impact experiments were conducted on semi-infinite targets of 1100 aluminum, 6061 aluminum alloy, mild steel, and commercially pure lead using spherically shaped and normally incident pyrex projectiles

    Phytochemical and Pharmacological potential of Annona cherimola-A Review

    Get PDF
    Several plant remedies have been employed in various medicinal systems for the treatment and management of different diseases. During past several years, there has been growing interest among the usage of various medicinal plants from traditional system of medicine for the treatment of different ailments. Traditional system of medicine consists of large number of plants with various medicinal and pharmacological importances and hence represents a priceless tank of new bioactive molecules. Annona cherimola Miller is a multipurpose tree with edible fruits and is one of the sources of the medicinal products. This review attempts to encompass the available literature on Annona cherimola with respect to its pharmacognostic characters, phytochemical constituents, pharmacological activities and traditional uses

    Hyperinsulinism-hyperammonaemia syndrome: novel mutations in the GLUD1 gene and genotype-phenotype correlations

    Get PDF
    Background: Activating mutations in the GLUD1 gene (which encodes for the intra-mitochondrial enzyme glutamate dehydrogenase, GDH) cause the hyperinsulinism–hyperammonaemia (HI/HA) syndrome. Patients present with HA and leucine-sensitive hypoglycaemia. GDH is regulated by another intra-mitochondrial enzyme sirtuin 4 (SIRT4). Sirt4 knockout mice demonstrate activation of GDH with increased amino acid-stimulated insulin secretion. Objectives: To study the genotype–phenotype correlations in patients with GLUD1 mutations. To report the phenotype and functional analysis of a novel mutation (P436L) in the GLUD1 gene associated with the absence of HA. Patients and methods: Twenty patients with HI from 16 families had mutational analysis of the GLUD1 gene in view of HA (n=19) or leucine sensitivity (n=1). Patients negative for a GLUD1 mutation had sequence analysis of the SIRT4 gene. Functional analysis of the novel P436L GLUD1 mutation was performed. Results: Heterozygous missense mutations were detected in 15 patients with HI/HA, 2 of which are novel (N410D and D451V). In addition, a patient with a normal serum ammonia concentration (21 µmol/l) was heterozygous for a novel missense mutation P436L. Functional analysis of this mutation confirms that it is associated with a loss of GTP inhibition. Seizure disorder was common (43%) in our cohort of patients with a GLUD1 mutation. No mutations in the SIRT4 gene were identified. Conclusion: Patients with HI due to mutations in the GLUD1 gene may have normal serum ammonia concentrations. Hence, GLUD1 mutational analysis may be indicated in patients with leucine sensitivity; even in the absence of HA. A high frequency of epilepsy (43%) was observed in our patients with GLUD1 mutations

    Analgesic and anti-inflammatory activity of ethanolic extracts of leaf and fruit pulp of Aegle marmelos in albino rats

    Get PDF
    Background: To study the analgesic and anti-inflammatory activity of the ethanolic extracts of leaf (LE) and fruit pulp (FE) of Aegle marmelos in comparison with the standard drugs pentazocine and diclofenac in albino rats. 56 healthy wistar albino rats of either sex were randomly divided into 14 groups of 4 each (n=4), weighing about 150-200grams were selected for the study. All drugs i.e. 1ml of 1% Carboxy methyl cellulose (CMC), pentazocine 10mg/kg (intraperitoneal), diclofenac 10 mg/kg and LE and FE at doses of 100mg/kg and 200mg/kg in 1% CMC (vehicle) were administered per oral one hour before the experiment.Methods: Analgesic activity was assessed by Eddy’s hot plate method (latency time) and acetic acid induced writhing (number of writhings) method. Anti-inflammatory activity was assessed by carrageenan induced hind paw edema method using digital plethysmometer.Results: Test drugs at doses LE 200mg/kg and FE 200mg/kg have shown significant increase in mean latency time in Eddy’s hot plate (P 0.05).Conclusions: Leaf extract (LE) and fruit extract (FE) at doses 200mg/kg have shown significant analgesic action and no anti-inflammatory action

    Molecular and Clinical Features of Heterogeneous Vancomycin Intermediate Staphylococcus aureus in Tertiary Care Hospitals of South India

    Get PDF
    Objectives: This study aimed to detect heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) among methicillin resistant S. aureus (MRSA) isolated from healthcare-associated infections and identify staphylococcal cassette chromosome mec (SCCmec) types. Methods: Isolation and identification of MRSA were done using standard bacteriological methods. Antimicrobial susceptibility testing was done using Kirby-Bauer disc diffusion and macrolide-lincosamide-streptogramin B (MLSB) phenotypes identified using D test. The minimum inhibitory concentration (MIC) of vancomycin was determined using agar dilution. hVISA were confirmed by modified population analysis profile-area under the curve (PAP-AUC) test. SCCmec types and Panton-Valentine leukocidin (pvl) were detected using multiplex PCR. Results: Out of 220 MRSA stains, 14 (6.4%) were hVISA. None of the MRSA isolate was vancomycin intermediate or resistant. All hVISA were susceptible to linezolid and teicoplanin. Macrolide-streptogramin B (MSB) phenotype was present in 42.9% hVISA. 92.9% hVISA strains had vancomycin MIC in the range 1-2 µg/mL. Majority of hVISA and vancomycin susceptible MRSA were isolated from skin and soft tissue infections. SCCmec III and IV were present in 50% and 35.7% hVISA respectively. 14.3% hVISA harboured SCCmec V. Conclusion: The rate of hVISA among MRSA was 6.4%. MRSA strains should be tested for hVISA before starting vancomycin treatment. None of the isolates was vancomycin intermediate or resistant. All the hVISA strains were susceptible to linezolid and teicoplanin. The majority of hVISA were isolated from skin and soft tissue infections. The majority hVISA harboured SCCmec III and IV. Keywords: MRSA; Hospital infection; Molecular typing; Vancomyci

    Qualitative Analysis and Antibacterial Activity of Pelargonium graveolenL’Herit

    Get PDF
    Medicinal plants are an important source of phytochemicals that offer traditional medicinal treatment of various ailments and one of the plants is Pelargonium Graveolens which was grown in Hyderabad province. The preliminary screening of their aerial leaves showed best results the presence of different phytochemical like alkaloids, flavonoids, glycosides, phenol, sterol and lignin found in Methanolic and Ethyl acetate extract. However chloroform extract revealed the absence of alkaloids and sterols, where as in Water extract flavonoids, phenol, sterol and lignin. The best resulted extracts from preliminary screening test were subjected to Antimicrobial studies like some on gram positive and gram negative bacterial strains which exhibited a significant effect.  The both ethyl acetate  and methanolic extracts were showed the similar zone of inhibition on gram positive bacteria (S.aurea and B.Subtilus) whereas  ethyl acetate  extract positive inhibition on k.pneumonia  when compare to methanolic  extract  and which are more active suppression on gram negative  bacterial (E.coli) in comparison with the standard antibiotic.

    Qualitative Analysis and Antibacterial Activity of Pelargonium graveolenL’Herit

    Get PDF
    Medicinal plants are an important source of phytochemicals that offer traditional medicinal treatment of various ailments and one of the plants is Pelargonium Graveolens which was grown in Hyderabad province. The preliminary screening of their aerial leaves showed best results the presence of different phytochemical like alkaloids, flavonoids, glycosides, phenol, sterol and lignin found in Methanolic and Ethyl acetate extract. However chloroform extract revealed the absence of alkaloids and sterols, where as in Water extract flavonoids, phenol, sterol and lignin. The best resulted extracts from preliminary screening test were subjected to Antimicrobial studies like some on gram positive and gram negative bacterial strains which exhibited a significant effect.  The both ethyl acetate  and methanolic extracts were showed the similar zone of inhibition on gram positive bacteria (S.aurea and B.Subtilus) whereas  ethyl acetate  extract positive inhibition on k.pneumonia  when compare to methanolic  extract  and which are more active suppression on gram negative  bacterial (E.coli) in comparison with the standard antibiotic.

    An observational, prospective, multicenter, natural history study of patients with mucopolysaccharidosis type IIIA

    Get PDF
    Mucopolysaccharidosis type IIIA (MPS IIIA, also known as Sanfilippo syndrome) is a rare genetic lysosomal storage disease characterized by early and progressive neurodegeneration resulting in a rapid decline in cognitive function affecting speech and language, adaptive behavior, and motor skills. We carried out a prospective observational study to assess the natural history of patients with MPS IIIA, using both standardized tests and patientcentric measures to determine the course of disease progression over a 2-year period. A cohort of 23 patients (7 girls, 16 boys; mean age 28–105 months at baseline) with a confirmed diagnosis of MPS IIIA were assessed and followed up at intervals of 3–6 months; cognitive function was measured using Bayley Scales of Infant and Toddler Development 3rd edition (BSID-III) to derive cognitive development quotients (DQ). Daily living, speech/ language development and motor skills were measured using the Vineland Adaptive Behavior Scale (VABS-II). Sleep–wake patterns, behavior and quality-of-life questionnaires were also reported at each visit using parent/ caregiver reported outcome tools. All patients had early onset severe MPS IIIA, were diagnosed before 74 months of age, and had cognitive scores below normal developmental levels at baseline. Patients less than 40 months of age at baseline were more likely to continue developing new skills over the first 6–12 months of follow-up. There was a high variability in cognitive developmental age (DA) in patients between 40 and 70 months of age; twothirds of these patients already had profound cognitive decline, with a DA ≤10 months. The highest cognitive DA achieved in the full study cohort was 34 months. Post hoc, patients were divided into two groups based on baseline cognitive DQ (DQ ≥50 or <50). Cognitive DQ decreased linearly over time, with a decrease from baseline of 30.1 and 9.0 points in patients with cognitive DQ ≥50 at baseline and cognitive DQ <50 at baseline, respectively. Over the 2-year study, VABS-II language scores declined progressively. Motor skills, including walking, declined over time, although significantly later than cognitive decline. No clear pattern of sleep disturbance was observed, but night waking was common in younger patients. Pain scores, as measured on the quality-of-life questionnaire, increased over the study period. The findings of this study strengthen the natural history data on cognitive decline in MPS IIIA and importantly provide additional data on endpoints, validated by the patient community as important to treat, that may form the basis of a multidomain endpoint capturing the disease complexity

    Atomic Hole Doping of Graphene

    Full text link
    Graphene is an excellent candidate for the next generation of electronic materials due to the strict two-dimensionality of its electronic structure as well as the extremely high carrier mobility. A prerequisite for the development of graphene based electronics is the reliable control of the type and density of the charge carriers by external (gate) and internal (doping) means. While gating has been successfully demonstrated for graphene flakes and epitaxial graphene on silicon carbide, the development of reliable chemical doping methods turns out to be a real challenge. In particular hole doping is an unsolved issue. So far it has only been achieved with reactive molecular adsorbates, which are largely incompatible with any device technology. Here we show by angle-resolved photoemission spectroscopy that atomic doping of an epitaxial graphene layer on a silicon carbide substrate with bismuth, antimony or gold presents effective means of p-type doping. Not only is the atomic doping the method of choice for the internal control of the carrier density. In combination with the intrinsic n-type character of epitaxial graphene on SiC, the charge carriers can be tuned from electrons to holes, without affecting the conical band structure
    • …
    corecore