Effect of case hardening on the wear and hardness properties of medium carbon steel for bone crushing application.

The majority of wear-related problems are connected to crushing machines because hammer failure frequently causes machine failure which eventually leads to machine downtime. Therefore, improving the reliability of crushing materials is necessary for effective production. This research investigation focused on the development of crushing material with appropriate strength properties that can function in critical, impact-prone, corrosive, and abrasive conditions. The current study used palm kernel shell, coconut shell, and sawdust powder as the media for medium carbon steel in order to valorize the agro waste. Carburising media PKS-composition, CS-composition, and SD-composition were changed to 40%: 30%: 30%, PKS-composition 100%, CS-composition 100%, and SD-composition 100%. The process was carried out in 1 h (60 mims), 1 h:30 min (90 min), 2 h (120 min), 2 h:30 (150 min), and 3 h (180 min) soak period with varied carburising temperatures of 900, 950, 1000, and 1050 °C. However, several characterisation and mechanical tests were carried out using an optical microscope, a spark spectrometer, a scanning electron microscope coupled with an energy dispersive spectrometer, wear tester to explore their microstructural features. Vicker's hardness tester, sliding wear tester, and a thermal gravimetric analysis testing machine were also employed. In order to establish reasons for failure other than the cyclic loading on the materials, the results were compared with the properties of as-received un-failed, and carburised medium carbon steel. The results of carburisation show that PKS penetrates carbon at a rate that is noticeably higher than that of other materials at various temperatures and times, indicating that carbon diffuses deeply into the material. Hence, this enhances the wear resistance, and sample's hardness number but decreased its impact toughness respectively.

[Promotion of Mental Health in Early Childhood Institutions in Disadvantaged Areas]. / Förderung der seelischen Gesundheit in Kitas in Quartieren mit besonderen Problemlagen.

A prevention programme for the promotion of psychological health was implemented in six early childhood education institutions, which caters to four different levels (courses for children, courses and counselling for parents, vocational training and supervision for paedagogic professionals, establishing networks within the social environment). New, low-threshold structures have been created in order to simplify the usage of prevention services and to develop meaningful connections between the support systems of health and education. The effects of the programme have been validated by means of a combination research design.

Enteric fever in an HIV/AIDS patient: Atypical manifestations.

Bloodstream infections with Salmonella typhi, is uncommon in human immunodeficiency virus (HIV)-infected persons. The symptoms in such patients are often non-specific and have a rather insidious onset and progression. We report a patient with sepsis and lower limb gangrene due to Salmonella typhi infection in an HIV-infected patient.

Complete failure of insulin-transmitted signaling, but not obesity-induced insulin resistance, impairs respiratory chain function in muscle.

The role of mitochondrial dysfunction in the development of insulin resistance and type 2 diabetes remains controversial. In order to specifically define the relationship between insulin receptor (InsR) signaling, insulin resistance, hyperglycemia, hyperlipidemia and mitochondrial function, we analyzed mitochondrial performance of insulin-sensitive, slow-oxidative muscle in four different mouse models. In obese but normoglycemic ob/ob mice as well as in obese but diabetic mice under high-fat diet, mitochondrial performance remained unchanged even though intramyocellular diacylglycerols (DAGs), triacylglycerols (TAGs), and ceramides accumulated. In contrast, in muscle-specific InsR knockout (MIRKO) and streptozotocin (STZ)-treated hypoinsulinemic, hyperglycemic mice, levels of mitochondrial respiratory chain complexes and mitochondrial function were markedly reduced. In STZ, but not in MIRKO mice, this was caused by reduced transcription of mitochondrial genes mediated via decreased PGC-1α expression. We conclude that mitochondrial dysfunction is not causally involved in the pathogenesis of obesity-associated insulin resistance under normoglycemic conditions. However, obesity-associated type 2 diabetes and accumulation of DAGs or TAGs is not associated with impaired mitochondrial function. In contrast, chronic hypoinsulinemia and hyperglycemia as seen in STZ-treated mice as well as InsR deficiency in muscle of MIRKO mice lead to mitochondrial dysfunction. We postulate that decreased mitochondrial mass and/or performance in skeletal muscle of non-diabetic, obese or type 2 diabetic, obese patients observed in clinical studies must be explained by genetic predisposition, physical inactivity, or other still unknown factors.

Gastric bypass surgery, but not caloric restriction, decreases dipeptidyl peptidase-4 activity in obese patients with type 2 diabetes.

The mechanism by which incretins and their effect on insulin secretion increase markedly following gastric bypass (GBP) surgery is not fully elucidated. We hypothesized that a decrease in the activity of dipeptidyl peptidase-4 (DPP-4), the enzyme which inactivates incretins, may explain the rise in incretin levels post-GBP. Fasting plasma DPP-4 activity was measured after 10-kg equivalent weight loss by GBP (n = 16) or by caloric restriction (CR,n = 14) in obese patients with type 2 diabetes. DPP-4 activity decreased after GBP by 11.6% (p = 0.01), but not after CR. The increased peak glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) response to oral glucose after GBP did not correlate with DPP-4 activity. The decrease in fasting plasma DPP-4 activity after GBP occurred by a mechanism independent of weight loss and did not relate to change in incretin concentrations. Whether the change in DPP-4 activity contributes to improved diabetes control after GBP remains therefore to be determined.

Virtual vs. optical colonoscopy in symptomatic gastroenterology out-patients: the case for virtual imaging followed by targeted diagnostic or therapeutic colonoscopy.

AIM: To compare virtual colonoscopy with optical colonoscopy findings in symptomatic patients. BACKGROUND: Computer tomographic colonography is an alternative to optical colonoscopy. Studies have shown that two-dimensional computer tomographic colonography does not have sufficient sensitivity. Three-dimensional computerized tomographic virtual colonoscopy compares well with optical colonoscopy for colorectal neoplasia screening in asymptomatic individuals. METHODS: One hundred patients aged 50 and older underwent same day virtual colonoscopy and optical colonoscopy. The endoscopists were unaware of the radiologist's report until the withdrawal phase of the endoscopy when segmental unblinding occurred. The virtual colonoscopy and optical colonoscopy findings were compared by using the unblinded optical colonoscopy as the reference standard. RESULTS: Pancolonic endoluminal virtual colonoscopy was achieved in 99 patients. Optical colonoscopy caecal intubation occurred in 91 patients. Direct comparison was possible in 90 patients. Both techniques revealed the three cancers detected. Virtual colonoscopy revealed 11 polyps > or = 6 mm diameter in nine patients. Optical colonoscopy revealed 10 polyps > or = 6 mm diameter in nine patients with a further 15-mm polyp discovered after segmental unblinding. CONCLUSION: In symptomatic patients, three-dimensional virtual colonoscopy is equivalent to optical colonoscopy for diagnosing colon cancer and clinically significant polyps. A case can be made for three-dimensional virtual colonoscopy as a primary modality followed if necessary by same day-targeted optical colonoscopy.

A nascent HIV type 1 epidemic among injecting drug users in Kabul, Afghanistan is dominated by complex AD recombinant strain, CRF35_AD.

Injecting drug use (IDU), common in global centers of heroin production, confers significant risk for HIV-1 infection. Once introduced into IDU networks, an explosive rise in HIV-1 infection typically occurs, fueled principally by needle sharing. New HIV-1 epidemics in IDUs have occurred in Russia, China, Thailand, Spain, Iran, and in other countries, and some have spread into other risk groups in their respective countries. In Afghanistan, the introduction of HIV-1 into IDU networks has begun, but a recent report of 3% HIV-1 prevalence suggests that the epidemic is still at an early stage. Here we establish, by complete genome sequencing and phylogenetic analysis of four viral strains from Afghan IDUs, that all are the same complex recombinant strain, combining HIV-1 subtypes A and D and herein termed CRF35_AD. Published partial HIV-1 sequences from an HIV-1 epidemic among IDUs in Iran, already at 23.2% HIV-1 prevalence, are either CRF35_AD or a related recombinant. Voluntary HIV-1 screening and harm reduction programs in Afghanistan, applied now, could limit the spread of HIV-1, both in IDUs and in other social networks.

Muscarinic M2 and M1 receptors reduce GABA release by Ca2+ channel modulation through activation of PI3K/Ca2+ -independent and PLC/Ca2+ -dependent PKC.

We measured pharmacologically isolated GABAergic currents from layer II/III neurons of the rat auditory cortex using patch-clamp recording. Activation of muscarinic receptors by muscarine (1 microM) or oxotremorine (10 microM) decreased the amplitude of electrically evoked inhibitory postsynaptic currents to about one third of their control value. Neither miniature nor exogenously evoked GABAergic currents were altered by the presence of muscarinic agonists, indicating that the effect was spike-dependent and not mediated postsynaptically. The presence of the N- or P/Q-type Ca(2+) channel blockers omega-conotoxin GVIA (1 microM) or omega-AgaTx TK (200 nM) greatly blocked the muscarinic effect, suggesting that Ca(2+)-channels were target of the muscarinic modulation. The presence of the muscarinic M(2) receptor (M(2)R) antagonists methoctramine (5 muM) or AF-DX 116 (1 microM) blocked most of the muscarinic evoked inhibitory postsynaptic current (eIPSC) reduction, indicating that M(2)Rs were responsible for the effect, whereas the remaining component of the depression displayed M(1)R-like sensitivity. Tissue preincubation with the specific blockers of phosphatidyl-inositol-3-kinase (PI(3)K) wortmannin (200 nM), LY294002 (1 microM), or with the Ca(2+)-dependent PKC inhibitor Gö 6976 (200 nM) greatly impaired the muscarinic decrease of the eIPSC amplitude, whereas the remaining component was sensitive to preincubation in the phospholipase C blocker U73122 (10 microM). We conclude that acetylcholine release enhances the excitability of the auditory cortex by decreasing the release of GABA by inhibiting axonal V-dependent Ca(2+) channels, mostly through activation of presynaptic M(2)Rs/PI(3)K/Ca(2+)-independent PKC pathway and-to a smaller extent-by the activation of M(1)/PLC/Ca(2+)-dependent PKC.

Drug resistance profile of human Mycobacterium avium complex strains from India.

PURPOSE: To determine minimum inhibitory concentration (MIC) of various anti-tuberculosis drugs for Mycobacterium avium complex (MAC) strains isolated from clinical samples. METHODS: Forty-nine human isolates of MAC were tested for susceptibility to nine chemotherapeutic agents. All isolates were from Indian patients suffering from chronic pulmonary mycobacteriosis. Drug susceptibility was performed both by agar dilution and MIC method. MIC values were analysed, both visually and by enzyme-linked immunosorbent assay reader. RESULTS: More than 40% of the MAC isolates were sensitive to ciprofloxacine (48.98%), amikacin (46.94%) and roxithromycin (42.86%) by the MIC method. In contrast, the isolates showed high degree of resistance to the first line antituberculosis drugs: only 28.6% were sensitive to rifampicine, 22.85% to isoniazid and ethambutol each and 36.7% were sensitive to streptomycin. In addition, 22.85% of the strains were sensitive to clofazimine and 34.7% to kanamycin. CONCLUSIONS: Results of the study confirm the suitability of the rapid broth micro dilution (MIC) method as a simple yet reliable method to assay for the drug susceptibility of nontuberculosis mycobacterium.

Prophage Finder: a prophage loci prediction tool for prokaryotic genome sequences.

Prophage loci often remain under-annotated or even unrecognized in prokaryotic genome sequencing projects. A PHP application, Prophage Finder, has been developed and implemented to predict prophage loci, based upon clusters of phage-related gene products encoded within DNA sequences. This application provides results detailing several facets of these clusters to facilitate rapid prediction and analysis of prophage sequences. Prophage Finder was tested using previously annotated prokaryotic genomic sequences with manually curated prophage loci as benchmarks. Additional analyses from Prophage Finder searches of several draft prokaryotic genome sequences are available through the Web site (http://bioinformatics.uwp.edu/~phage/DOEResults.php) to illustrate the potential of this application.

Brazil nut effect and excluded volume attraction in vibrofluidized granular mixtures.

A two dimensional bi-disperse vibrofluidized granular mixture is studied in the rapid flow regime, where particle interactions occur due to instantaneous collisions. Both experiments and simulations are carried out, and these show the existence of two phenomena which have been observed only in very dense granular flows or in equilibrium systems. The Brazil nut phenomenon, which involves the rise of larger particles in a granular mixture upon vibration, has been observed in dense systems due to the percolation of small particles though the interstitial spaces between the large particles, or due to convection rolls. In the present case, where neither effect is present, it is observed that the fluidization of the smaller particles by vibration results in an exponentially decaying density profile, at heights large compared to the particle diameter, and thereby a pressure field that decreases with height. The larger particles, suspended in this decaying pressure field, experience a larger pressure at the bottom and a smaller pressure on top, and they rise to a height where the net force caused by the decreasing pressure is balanced by the weight of the particle. An attractive force between the large particles, similar to the entropic attraction effect in mixtures of colloids and polymers, is also observed in this nonequilibrium system, because when the distance between the large particles is less than the small particle diameter, the pressure between the large particles is smaller than that on the outside. Analytical results are derived for each of these effects, and these are in agreement with the experimental and simulation results.

'Nature-inspired' drug-protein complexes as inhibitors of Abeta aggregation.

Protein-protein interactions are a regulatory mechanism for a number of physiological and pathological cellular processes. Neurodegenerative diseases, such as AD (Alzheimer's disease), are associated with the accelerated production or delayed clearance of protein aggregates. Hence, inhibition of pathologic protein-protein interactions is a very attractive mechanism for drug development. This review focuses on a novel therapeutic strategy to inhibit the de novo formation of protein aggregates. Inspired by strategies used in Nature and optimized over millions of years of evolution, we have created a bifunctional molecule [SLF (synthetic ligand for FK506-binding protein)-CR (Congo Red)] that is able to block Abeta (amyloid beta) aggregation by borrowing the surface and steric bulk of a cellular chaperone.

Drug-sensitivity profile of clinical Mycobacterium tuberculosis isolates--a retrospective study from a chest-disease institute in India.

Multi-drug-resistant tuberculosis (MDR-TB) is a major public-health problem, because treatment is complicated and patients remain infectious for months or years, despite receiving the best available therapy. To gain better understanding of MDR-TB, a retrospective study was initiated to determine the level of drug resistance among patients in a chest-disease institute in India. Two hundred and sixty-three isolates from treatment-failure pulmonary tuberculosis patients (20-70 years) were studied. Drug-sensitivity testing was performed by the modified-proportion method. First- and second-line drugs, along with two quinolone drugs (ofloxacin and ciprofloxacin), were tested. Patients included in this study did not improve with therapy; however, 151 isolates (57.5 %) were susceptible to all four first-line antituberculosis drugs. This study reports low resistance to fluoroquinolones among the strains present in these patients.

Velocity distribution for a two-dimensional sheared granular flow.

The velocity distribution for a two-dimensional collection of disks of number density n per unit area and radius a in a channel of width L is studied. The particle-particle collisions are considered to be inelastic with a coefficient of restitution e, while the particle-wall coefficients of restitution are inelastic with a tangential and normal coefficients of restitution, e(t) and e(n), respectively. The Knudsen number, which is the ratio of the channel width and the mean free path of the particles, is varied from Kn<<1 to Kn>>1. In the limit of high Knudsen number, the distribution function for the streamwise velocity is bimodal, as predicted by theory [J. Fluid Mech. 340, 3l9 (1997)]], and the scalings of the moments of the velocity distribution with the Knudsen number are in agreement with the theory. In the low Knudsen number limit, the distribution function for the streamwise velocity is a Gaussian if the coefficient of restitution is close to 1, but assumes the form of a "composite Gaussian" if the coefficient of restitution is not close to 1. The distribution function has a complex structure in the intermediate regime, where there are three maxima in the distribution function near the wall, while the distribution function is bimodal at the center. The granular temperature is accurately predicted by kinetic theory at the center of the channel, but there is dissipation at the wall due to inelastic particle-wall collisions, which results in a significant decrease in the temperature even when the coefficient of restitution is 0.9; this finding is in agreement with previous results with bumpy wall boundary conditions and with specular reflection conditions. The slip velocity at the wall has a power law dependence on the Knudsen number, and the exponent in this power law depends on the coefficients of restitution.

Private pharmacies in tuberculosis control--a neglected link.

In most settings in India, private pharmacies dispense prescriptions for anti-tuberculosis drugs made out by private practitioners. In a cross-sectional study, we assessed the dispensing practices for tuberculosis and knowledge about the national tuberculosis programme of 300 pharmacies. In all, 2800 prescriptions were dispensed monthly by the pharmacies. Doctors' prescriptions were for durations of several months, but half of the patients bought drugs one dose at a time for self-administration. This practice might promote drug resistance. Although 95% of pharmacists were not aware of the existence of the tuberculosis programme, the majority (97%) were willing to learn and contribute towards tuberculosis control. The need and the potential of private pharmacies for participation in tuberculosis control are highlighted.

Disease progression markers during asymptomatic phase of HIV-1 infected children with unimpaired CD4+ cell values: evaluation of repeat CD4+ cell evaluation vs. other immunological parameters.

The availability of a marker that could predict the course of disease progression in HIV-infected individuals would be of considerable relevance during the asymptomatic stage in order to undertake timely prophylactic measures. A prospective study was undertaken in a group of 42 children suffering from thalassemia major with HIV-1 infection to assess the status of immune parameters, such as peripheral CD4+ T lymphocyte (CD4+ cell) percentage, delayed type of hypersensitivity (DTH) response to recall antigens, detection rate and levels of p24 antigen, and levels of beta-2 microglobulin and cytokines in serum. All were assessed at an interval of 2 years during the asymptomatic period, (baseline and follow-up assessments) in relation to the development of AIDS defining illness within a follow-up period of 3 years. No difference could be observed in the mean CD4+ cell percentage at baseline between those who progressed subsequently to develop AIDS within the follow-up period (progressors) and those who did not (non-progressors). However, at the point of follow-up assessment the progressor group showed significantly lower CD4+ cell percentage compared to the non-progressor group (33 +/- 4.9 vs. 22 +/- 5.6; p < 0.05), although in the progressor group there was no correlation of the baseline and follow-up CD4+ cell percentage with the duration of the AIDS-free interval. However, in the progressor group there was a strong negative correlation between the rate of decline in CD4+ cell percentage and subsequent duration of the AIDS-free interval (r = -0.859). Analysis of additional immune parameters at baseline revealed that the progressor group, despite having CD4+ cell values comparable to non-progressors, showed impaired DTH response (number and total induration of positive responses being 2.0 +/- 1.23 and 6.2 +/- 1.4 in the former group vs. 3.2 +/- 0.76 and 12.6 +/- 3.80 in the later group; p < 0.05 for both the parameters), and elevated levels (mg/l) of serum beta-2 microglobulin (2.92 +/- 0.89 vs. 1.38 +/- 0.43; p < 0.05). The serum cytokine profile at baseline in the progressor group showed a T helper type-2 (Th2) dominant pattern, i.e. elevation of interleukin-4 (IL-4) and interleukin-10 (IL-10) levels with decreased levels of interleukin-2 (IL-2) and gamma interferon (gamma-IFN) compared to the non-progressor group that showed a T helper type-1 (Th1) dominant profile, i.e., elevation of IL-1 and gamma-IFN level with decreased levels of IL-4 and IL-10 (p < 0.05 for all four cytokines). The present study points out that rate of decline rather than single point of assessment of CD4+ cell values is a more reliable predictor for disease progression in HIV-1 infected children. In addition, parameters such as DTH response, serum levels of beta-2 microglobulin and serum cytokine profile, may provide valuable predictors of subsequent fall in CD4+ cell value.

Inhibition of the in-vitro growth of Mycobacterium tuberculosis by a phytosiderophore.

Non-compliance by patients and poor clinical management due to the use of incorrect regimens are the main reasons for the development of drug resistance by mycobacterial strains. New strategies for the control of multi-drug-resistant mycobacterial strains have become a necessity for proper management of tuberculosis, which, according to the WHO report (1997), is estimated to remain among the top 10 mortality-causing diseases of the twenty-first century. One of the strategies is the use of iron-sequestering agents like siderophores as active therapeutic agents in the treatment of tuberculosis. This report describes for the first time the inhibition of the growth of Mycobacterium tuberculosis H37Ra in vitro by a phytosiderophore isolated from the root washings of Tephrosia purpurea. This finding may help in the establishment of a new drug regimen which will be more effective in the treatment of tuberculosis.

Spatiotemporal dynamics near a supercritical Turing-Hopf bifurcation in a two-dimensional reaction-diffusion system.

Pattern formation in semiconductor heterostructures is studied on the basis of a spatially two-dimensional model of reaction-diffusion type. In particular, we investigate the neighborhood of a codimension-two Turing-Hopf instability by analytical methods. Amplitude equations are derived which predict the absence of mixed modes but extended ranges of bistability between homogeneous oscillatory states and hexagonal Turing patterns. Our results are confirmed by numerical simulations. The features are not confined to a neighborhood of the bifurcation point so that the conclusions of the weakly nonlinear analysis explain the observations in large portions of the parameter space at least qualitatively

X-ray diffraction, differential scanning calorimetry and thermogravimetry combined with infrared analysis of freeze-dried prednisolone hemisuccinate.

In this study, the thermal behaviour of freeze-dried prednisolone hemisuccinate (Prednisolut) was investigated by means of X-ray scattering, differential scanning calorimetry (DSC) and fourier transformation infra-red analysis (FT-IR).