Design Fatigue Lives of Polypropylene Fibre Reinforced Polymer Concrete Composites

Flexural fatigue behavior of Poly-propylene fibre reinforced polymer concrete composites (PFRPCC) has been investigated at various stress levels and the statistical analysis of the data thus obtained has been carried out. Polymer Concrete Composite (PCC) samples without addition of any type of fibres were also tested for flexural fatigue.  Forty specimens of PCC and One hundred and Forty One specimens of PFRPCC containing 0.5%, 1.0% and 2.0% polypropylene fibres were tested in fatigue using a MTS servo controlled test system. Fatigue life distributions of PCC as well as PFRPCC are observed to approximately follow a two parameter Weibull distribution with correlation coefficient exceeding 0.9. The parameters of the Weibull distribution have been obtained by various methods. Failure probability, which is an important parameter in the fatigue design of materials, has been used to obtain the design fatigue lives for the material. Comparison of design fatigue life of PCC and PFRPCC has been carried out and it is observed that addition of fibres enhances the design fatigue life of PCC

DNase I nick translation in situ on meiotic chromosomes of the mouse, Mus musculus

DNase-I-sensitive sites have been located on the meiotic chromosomes of the mouse, Mus musculus, by the in situ DNase I nick-translation method. We find that: (1) of all the cell types studied, pachytene nuclei are the most sensitive to DNase I; (2) in diplotene the nicks occur preferentially in the vicinity of chiasmata; (3) the sex chromosomes are also sensitive to the enzyme despite their transcriptional quiescence; and (4) in the sex bivalent the nicks are primarily observed in the putative region of recombination. We conclude that, in addition to discriminating between the transcriptionally active and inactive states of chromatin, DNase I identifies recombination-specific chromatin changes in meiotic prophase

Novel Processing of Unique Ceramic-Based Nuclear Materials and Fuels

Advances in nuclear reactor technology and the use of gas-cooled fast reactors require the development of new materials that can operate at the higher temperatures expected in these systems. These include refractory alloys base on Nb, Zr, Ta, Mo, W, and Re; ceramics and composites such as those based on silicon carbide (SiCf-SiC); carbon-carbon composites; and advanced coatings. Besides the ability to handle higher expected temperatures, effective heat transfer between reactor componets is necessary for improved efficiency. Improving thermal conductivity of the materials used in nuclear fuels and other temperature critical components can lower the center-line fuel temperature and thereby enhance durability and reduce the risk of premature failure

Haemoglobinopathies- thalassaemias and abnormal haemoglobins in Eastern Uttar Pradesh and adjoining districts of neighbouring states

The haemoglobinopathies- thalassaemias and abnormal haemoglobins- constitute a major burden of genetic diseases in India. Our study, based on index cases from 120 families detected between May 1999 and May 2003, highlights the ethnic distribution of haemoglobinopathies in regions in and around Varanasi comprising 8-10 districts of eastern Uttar Pradesh and adjoining districts of Bihar, Jharkhand, Chhattisgarh and Madhya Pradesh. Homozygous and heterozygous β-thalassaemia was the most common (66.9%), with thalassaemic haemoglobinopathies HbE-β-thalassaemia (15.9%) and HbS-β-thalasseamia (7.8%) contributing to almost a quarter of the cases. Along with HbSS disease (4.3%), the results indicate a confluence of β-thalassaemia, HbS and HbE in this region. IVS1-5 nt was the most common mutation in the few carriers analysed for mutation detection. The significance of the study lies in the demonstration of wide prevalence of β-thalassaemia across all castes and communities of this region, with migrant population groups of Sindhis and Punjabis comprising only 5.8% of the index cases. Also, HbE seems to have a much higher presence in this region than so far believed and HbS has a significant presence in general castes as well

Cytokines induce effector T-helper cells during invasive aspergillosis; what we have learned about T-helper cells?

Invasive aspergillosis caused by Aspergillus species (Aspergillus fumigatus, A. flavus and A. terreus) is life-threatening infections in immunocompromised patients. Understanding the innate and adaptive immune response particularly T-helper cells (TH-cells) against these Aspergillus species and how the different sub-set of TH-cells are regulated by differentiating cytokines at primary target organ site like lung, kidney and brain is of great significance to human health. This review focuses on presentation of Aspergillus through Antigen presenting cells (APCs) to the naive CD4+ T-cells in the host. The production of differentiating/effector cytokines that activate following TH-cells e.g., TH1, TH2, TH9 and TH17 has been reported in association or alone in allergic or invasive aspergillosis. Chemokines (CXCL1, CXCL2, CCL1 and CCL20) and their receptors associated to these TH-cells have also been observed in invasive aspergillosis. Thus, further study of these TH-cells in invasive aspergillosis and other elements of adaptive immune response with Aspergillus species are required in order to have a better understanding of host response for safer and effective therapeutic outcome

Sequential emergence and clinical implications of viral mutants with K70E and K65R mutation in reverse transcriptase during prolonged tenofovir monotherapy in rhesus macaques with chronic RT-SHIV infection.

BackgroundWe reported previously on the emergence and clinical implications of simian immunodeficiency virus (SIVmac251) mutants with a K65R mutation in reverse transcriptase (RT), and the role of CD8+ cell-mediated immune responses in suppressing viremia during tenofovir therapy. Because of significant sequence differences between SIV and HIV-1 RT that affect drug susceptibilities and mutational patterns, it is unclear to what extent findings with SIV can be extrapolated to HIV-1 RT. Accordingly, to model HIV-1 RT responses, 12 macaques were inoculated with RT-SHIV, a chimeric SIV containing HIV-1 RT, and started on prolonged tenofovir therapy 5 months later.ResultsThe early virologic response to tenofovir correlated with baseline viral RNA levels and expression of the MHC class I allele Mamu-A*01. For all animals, sensitive real-time PCR assays detected the transient emergence of K70E RT mutants within 4 weeks of therapy, which were then replaced by K65R mutants within 12 weeks of therapy. For most animals, the occurrence of these mutations preceded a partial rebound of plasma viremia to levels that remained on average 10-fold below baseline values. One animal eventually suppressed K65R viremia to undetectable levels for more than 4 years; sequential experiments using CD8+ cell depletion and tenofovir interruption demonstrated that both CD8+ cells and continued tenofovir therapy were required for sustained suppression of viremia.ConclusionThis is the first evidence that tenofovir therapy can select directly for K70E viral mutants in vivo. The observations on the clinical implications of the K65R RT-SHIV mutants were consistent with those of SIVmac251, and suggest that for persons infected with K65R HIV-1 both immune-mediated and drug-dependent antiviral activities play a role in controlling viremia. These findings suggest also that even in the presence of K65R virus, continuation of tenofovir treatment as part of HAART may be beneficial, particularly when assisted by antiviral immune responses

Aedes aegypti lachesin protein binds to the domain III of envelop protein of Dengue virus-2 and inhibits viral replication.

Dengue virus (DENV) comprises of four serotypes (DENV-1 to -4) and is medically one of the most important arboviruses (arthropod-borne virus). DENV infection is a major human health burden and is transmitted between humans by the insect vector, Aedes aegypti. Ae. aegypti ingests DENV while feeding on infected humans, which traverses through its gut, haemolymph and salivary glands of the mosquito before being injected into a healthy human. During this process of transmission, DENV must interact with many proteins of the insect vector, which are important for its successful transmission. Our study focused on the identification and characterisation of interacting protein partners in Ae. aegypti to DENV. Since domain III (DIII) of envelope protein (E) is exposed on the virion surface and is involved in virus entry into various cells, we performed phage display library screening against domain III of the envelope protein (EDIII) of DENV-2. A peptide sequence showing similarity to lachesin protein was found interacting with EDIII. The lachesin protein was cloned, heterologously expressed, purified and used for in vitro interaction studies. Lachesin protein interacted with EDIII and also with DENV. Further, lachesin protein was localised in neuronal cells of different organs of Ae. aegypti by confocal microscopy. Blocking of lachesin protein in Ae. aegypti with anti-lachesin antibody resulted in a significant reduction in DENV replication

ADVANCED PROCESS MODEL FOR POLYMER DERIVED CERAMIC PROCESSING

ABSTRACT Pyrolysis of preceramic polymers allows a new type of ceramic materials to be processed at a relatively low temperature. The ceramics via polymer pyrolysis display a number of exceptional mechanical, thermal and chemical properties, including high thermal stability, high oxidation/creep resistance, etc. Moreover, they offer better geometrical accuracy compared to conventional ceramics. In addition, thermal induced pyrolysis of organometallic polymer precursors offers the possibility of net shape manufacturing at a lower temperature compared to traditional powder sintering process. The pyrolysis of polymer precursors involves curing of polymer precursors in which the polymer undergoes crosslinking to form a green body, followed by a pyrolysis stage that involves the formation of amorphous SiC and crystallization of SiC at a higher temperature. The source material changes phase and composition continuously during polymer pyrolysis based ceramic process. Chemical reactions and transport phenomena vary accordingly. To obtain ceramics with high uniformity of microstructure and species without crack, transport phenomena in material processing needs to be better understood and a process model needs to be developed to optimize the fabrication process. In this paper, a numerical model is developed, including heat and mass transfer, polymer pyrolysis, species transport, chemical reactions and crystallization. The model is capable of accurately predicting the polymer pyrolysis and chemical reactions of the source material. Pyrolysis of a sample with certain geometry is simulated. The effects of heating rate, particle size and initial porosity on porosity evolution, mass loss and reaction rate are investigated. Optimal conditions for the manufacturing are also proposed

Relation of delayed recovery of myocardial function after takotsubo cardiomyopathy to subsequent quality of life

Takotsubo cardiomyopathy (TTC) has generally been regarded as a relatively transient disorder, characterized by reversible regional left ventricular systolic dysfunction. However, most patients with TTC experience prolonged lassitude or dyspnea after acute attacks. Although this might reflect continued emotional stress, myocardial inflammation and accentuated brain-type natriuretic peptide (BNP) release persist for at least 3 months. We therefore tested the hypotheses that this continued inflammation is associated with (1) persistent contractile dysfunction and (2) consequent impairment of quality of life. Echocardiographic parameters (global longitudinal strain [GLS], longitudinal strain rate [LSR], and peak apical twist [AT]) were compared acutely and after 3 months in 36 female patients with TTC and 19 age-matched female controls. Furthermore, correlations were sought between putative functional anomalies, inflammatory markers (T2 score on cardiovascular magnetic resonance, plasma NT-proBNP, and high-sensitivity C-reactive protein levels), and the physical composite component of SF36 score (SF36-PCS). In TTC cases, left ventricular ejection fraction returned to normal within 3 months. GLS, LSR, and AT improved significantly over 3-month recovery, but GLS remained reduced compared to controls even at follow-up (-17.9 ± 3.1% vs -20.0 ± 1.8%, p = 0.003). Impaired GLS at 3 months was associated with both persistent NT-proBNP elevation (p = 0.03) and reduced SF36-PCS at ≥3 months (p = 0.04). In conclusion, despite normalization of left ventricular ejection fraction, GLS remains impaired for at least 3 months, possibly as a result of residual myocardial inflammation. Furthermore, perception of impaired physical exercise capacity ≥3 months after TTC may be explained by persistent myocardial dysfunction

Two neutrino positron double beta decay of 106^{106}Cd for 0+→0+0^+ \to 0^+ transition

The two neutrino positron double beta decay of $^{106}$Cd for 0$^{+} \to$ 0$^{+}$ transition has been studied in the Hartree-Fock-Bogoliubov model in conjunction with the summation method. In the first step, the reliability of the intrinsic wave functions of $^{106}$Cd and $^{106}$Pd nuclei has been tested by comparing the theoretically calculated results for yrast spectra, reduced $B(E2$:$0^{+}\to 2^{+})$ transition probabilities, quadrupole moments $Q(2^{+})$ and gyromagnetic factors $g(2^{+})$ with the available experimental data. In the second step, the nuclear transition matrix element $M_{2\nu}$ and the half-life $T_{1/2}^{2\nu}$ for 0$^{+}\to$ 0$^{+}$ transition have been calculated with these wave functions. Moreover, we have studied the effect of deformation on nuclear transition matrix element M$_{2\nu}.$Comment: 20 page