MOCCA-SURVEY database I. Accreting white dwarf binary systems in globular clusters -- IV. cataclysmic variables -- properties of bright and faint populations

We investigate here populations of cataclysmic variables (CVs) in a set of 288 globular cluster (GC) models evolved with the MOCCA code. This is by far the largest sample of GC models ever analysed with respect to CVs. Contrary to what has been argued for a long time, we found that dynamical destruction of primordial CV progenitors is much stronger in GCs than dynamical formation of CVs, and that dynamically formed CVs and CVs formed under no/weak influence of dynamics have similar white dwarf mass distributions. In addition, we found that, on average, the detectable CV population is predominantly composed of CVs formed via typical common envelope phase (CEP) ($\gtrsim70$ per cent), that only $\approx2-4$ per cent of all CVs in a GC is likely to be detectable, and that core-collapsed models tend to have higher fractions of bright CVs than non-core-collapsed ones. We also consistently show, for the first time, that the properties of bright and faint CVs can be understood by means of the pre-CV and CV formation rates, their properties at their formation times and cluster half-mass relaxation times. Finally, we show that models following the initial binary population proposed by Kroupa and set with low CEP efficiency better reproduce the observed amount of CVs and CV candidates in NGC 6397, NGC 6752 and 47 Tuc. To progress with comparisons, the essential next step is to properly characterize the candidates as CVs (e.g. by obtaining orbital periods and mass ratios).Comment: 18 pages, 13 figures; accepted for publication in MNRA

The 2009 outburst of accreting millisecond pulsar IGR J17511-3057 as observed by SWIFT and RXTE

The twelfth accretion-powered millisecond pulsar, IGR J17511-3057, was discovered in September 2009. In this work we study its spectral and timing properties during the 2009 outburst based on Swift and RXTE data. Our spectral analysis of the source indicates only slight spectral shape evolution during the entire outburst. The equivalent width of the iron line and the apparent area of the blackbody emission associated with the hotspot at the stellar surface both decrease significantly during the outburst. This is consistent with a gradual receding of the accretion disc as the accretion rate drops. The pulse profile analysis shows absence of dramatic shape evolution with a moderate decrease in pulse amplitude. This behaviour might result from a movement of the accretion column footprint towards the magnetic pole as the disc retreats. The time lag between the soft and the hard energy pulses increase by a factor of two during the outburst. A physical displacement of the centroid of the accretion shock relative to the blackbody spot or changes in the emissivity pattern of the Comptonization component related to the variations of the accretion column structure could cause this evolution. We have found that IGR J17511-3057 demonstrates outburst stages similar to those seen in SAX J1808.4-3658. A transition from the "slow decay" into the "rapid drop" stage, associated with the dramatic flux decrease, is also accompanied by a pulse phase shift which could result from an appearance of the secondary spot due to the increasing inner disc radius.Comment: 12 pages, 10 figures, MNRAS, in press. Title correcte

Varying disc-magnetosphere coupling as the origin of pulse profile variability in SAX J1808.4-3658

Accreting millisecond pulsars show significant variability of their pulse profiles, especially at low accretion rates. On the other hand, their X-ray spectra are remarkably similar with not much variability over the course of the outbursts. For the first time, we have discovered that during the 2008 outburst of SAX J1808.4-3658 a major pulse profile change was accompanied by a dramatic variation of the disc luminosity at almost constant total luminosity. We argue that this phenomenon is related to a change in the coupling between the neutron star magnetic field and the accretion disc. The varying size of the pulsar magnetosphere can influence the accretion curtain geometry and affect the shape and the size of the hotspots. Using this physical picture, we develop a self-consistent model that successfully describes simultaneously the pulse profile variation as well as the spectral transition. Our findings are particularly important for testing the theories of accretion onto magnetized neutron stars, better understanding of the accretion geometry as well as the physics of disc-magnetosphere coupling. The identification that varying hotspot size can lead to pulse profile changes has profound implications for determination of the neutron star masses and radii.Comment: 12 pages, 5 figures and 3 tables; accepted to MNRA

Dynamics of liquid He-4 in confined geometries from Time-Dependent Density Functional calculations

We present numerical results obtained from Time-Dependent Density Functional calculations of the dynamics of liquid He-4 in different environments characterized by geometrical confinement. The time-dependent density profile and velocity field of He-4 are obtained by means of direct numerical integration of the non-linear Schrodinger equation associated with a phenomenological energy functional which describes accurately both the static and dynamic properties of bulk liquid He-4. Our implementation allows for a general solution in 3-D (i.e. no symmetries are assumed in order to simplify the calculations). We apply our method to study the real-time dynamics of pure and alkali-doped clusters, of a monolayer film on a weakly attractive surface and a nano-droplet spreading on a solid surface.Comment: q 1 tex file + 9 Ps figure

Management of cardiac fibrosis in diabetic rats; the role of peroxisome proliferator activated receptor gamma (PPAR-gamma) and calcium channel blockers (CCBs)

<p>Abstract</p> <p>Background</p> <p>Diabetes mellitus (DM) and hypertension (HTN) are accused of being responsible for the development of the cardiac fibrosis due to severe cardiomyopathy.</p> <p>Methods</p> <p>Blood glucose (BG) test was carried out, lipid concentrations, tumor necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-β), matrix metalloproteinase (MMP-2), collagen-I and collagen-III were measured in male <it>Albino </it>rats weighing 179-219 g. The rats were divided into five groups, kept on either control diet or high fat diet (HFD), and simultaneously treated with rosiglitazone (PPAR-gamma) only for one group with 3 mg/kg/day via oral route for 30 days, and with rosiglitazone and felodipine combination for another group with 3 mg/kg/day and 5 mg/kg/day, respectively via oral route for 30 days.</p> <p>Results</p> <p>Diabetic hypertensive (DH) rats which fed on a HFD, injected with streptozotocin (STZ) (i.p.) and obstruction for its right kidney was occurred develop hyperglycemia, hypertension, cardiac fibrosis, hypertriglyceridemia, hypercholesterolemia, increased TNF-α, increased TGF-β, decreased MMP-2, increased collagen-I and increased collagen-III, when compared to rats fed on control diet. Treating the DH rats with rosiglitazone only causes a significant decrease for BG levels by 52.79%, triglycerides (TGs) by 24.05%, total cholesterol (T-Chol) by 30.23%, low density lipoprotein cholesterol (LDL-C) by 40.53%, TNF-α by 20.81%, TGF-β by 46.54%, collagen-I by 48.11% and collagen-III by 53.85% but causes a significant increase for MMP-2 by 272.73%. Moreover, Treating the DH rats with rosiglitazone and felodipine combination causes a significant decrease for BG levels by 61.08%, blood pressure (BP) by 16.78%, TGs by 23.80%, T-Chol by 33.27%, LDL-C by 45.18%, TNF-α by 22.82%, TGF-β by 49.31%, collagen-I by 64.15% and collagen-III by 53.85% but causes a significant increase for MMP-2 by 290.91%. Rosiglitazone alone failed to decrease the BP in DH rats in the current dosage and duration.</p> <p>Conclusion</p> <p>Our results indicate that the co-existence of diabetes and hypertension could induce cardiomyopathy which could further result in cardiac fibrosis, and that combination treatment with rosiglitazone and felodipine has a great protective role against the metabolic abnormalities, meanwhile, the treatment with rosiglitazone alone has a protective role with a minimal effect against these abnormalities and has no effect on decreasing BP in these cases which may lead to coronary artery diseases (CADs) in future.</p

MicroRNA-106b~25 cluster is upregulated in relapsed MLL-rearranged pediatric acute myeloid leukemia

The most important reason for therapy failure in pediatric acute myeloid leukemia (AML) is relapse. In order to identify miRNAs that contribute to the clonal evolution towards relapse in pediatric AML, miRNA expression profiling of 127 de novo pediatric AML cases were used. In the diagnostic phase, no miRNA signatures could be identified that were predictive for relapse occurrence, in a large pediatric cohort, nor in a nested mixed lineage leukemia (MLL)-rearranged pediatric cohort. AML with MLL- rearrangements are found in 15-20% of all pediatric AML samples, and reveal a relapse rate up to 50% for certain translocation partner subgroups. Therefore, microRNA expression profiling of six paired initial diagnosis-relapse MLL-rearranged pediatric AML samples (test cohort) and additional eight paired initial diagnosisrelapse samples with MLL-rearrangements (validation cohort) was performed. A list of 53 differentially expressed miRNAs was identified of which the miR-106b~25 cluster, located in intron 13 of MCM7, was the most prominent. These differentially expressed miRNAs however could not predict a relapse in de novo AML samples with MLLrearrangements at diagnosis. Furthermore, higher mRNA expression of both MCM7 and its upstream regulator E2F1 was found in relapse samples with MLL-rearrangements. In conclusion, we identified the miR-106b~25 cluster to be upregulated in relapse pediatric AML with MLL-rearrangements

Internet-based search of randomised trials relevant to mental health originating in the Arab world

BACKGROUND: The internet is becoming a widely used source of accessing medical research through various on-line databases. This instant access to information is of benefit to busy clinicians and service users around the world. The population of the Arab World is comparable to that of the United States, yet it is widely believed to have a greatly contrasting output of randomised controlled trials related to mental health. This study was designed to investigate the existence of such research in the Arab World and also to investigate the availability of this research on-line. METHODS: Survey of findings from three internet-based potential sources of randomised trials originating from the Arab world and relevant to mental health care. RESULTS: A manual search of an Arabic online current contents service identified 3 studies, MEDLINE, EMBASE, and PsycINFO searches identified only 1 study, and a manual search of a specifically indexed, study-based mental health database, PsiTri, revealed 27 trials. CONCLUSION: There genuinely seem to be few trials from the Arab world and accessing these on-line was problematic. Replication of some studies that guide psychiatric/psychological practice in the Arab world would seem prudent

A case series of unusual root canal morphology

Aim: The thorough knowledge of tooth morphology and its variations is essential for successful endodontic treatment.Case report: This article reports an unusual root canal configuration that was detected in a maxillary central incisor with two root canals , mandibular canine with two canals and mandibular canine with two roots and  root canals.Conclusions: These case reports  increase  the awareness of clinicians on variations in the root canal anatomy so that complete  disinfection and obturation of the root canal system is possible

EFFECT OF RENNIN INHIBITORS AND ANGIOTENSIN II RECEPTOR ANTAGONISTS ON LEFT VENTRICULAR HYPERTROPHY IN RENOVASCULAR HYPERTENSIVE RATS

Objective: Left ventricular (LV) hypertrophy involves numerous structural adaptations that may lead to ventricular dysfunction and eventually, heart failure. Particular emphasis is placed on the molecular mechanisms that govern the development of hypertrophy and may lead to maladaptive structural changes resulting in adverse cardiac events. This study investigates the effectiveness of Valsartan (Val) which is an angiotensinII receptor antagonist and Aliskiren (Ali) which is a direct rennin inhibitor in the treatment of cardiac remodeling resulted from renovascular hypertension, particularly left ventricular hypertrophy, and to address the molecular mechanisms underlying them.Methods: 24 male albino rats were randomly divided into 4 main groups (n=6 each), normal control rats (N), hypertensive control rats (HC), Val treated hypertensive rats (Val, 8 mg/kg/day orally) and Ali treated hypertensive rats (Ali, 25 mg/kg/day orally).Results: At the end of 4 weeks HC rats showed enhanced hypertrophic response (higher heart weight/body weight ratio) and dyslipidemia (lower high density lipoprotein "HDL-c" and higher triacyl glycerol "TAG") and a significant deletion of antioxidant enzymes in comparison with N group. The β myosin heavy chain "βMHC", regulator of calcineurin-1 "RCAN1", nuclear factor kappa B "NFκB" and inducible nitric oxide synthase "iNOS" was markedly elevated. While, α myosin heavy chain "αMHC" was markedly decreased as compared with N group. On the other hand Val treated hypertensive rats and Ali treated hypertensive rats showed a significant decrease in heart weight/body weight ratio, improved lipogram pattern and higher levels of antioxidant enzymes. While, cardiac β-MHC, RCAN-1, NFκB and iNOS were significantly decreased as compared with HC group. Both Val treated hypertensive rats and Ali treated hypertensive rats showed a significant increase in α-MHC, compared with HC groupConclusion: The results reported in this study suggested that chronic untreated hypertension induced a pathological hypertrophy. Administration of the Val or Ali individually exerted beneficial effects regarding the improved lipogram pattern and anti-oxidant enzymes levels, as well as cardiac hypertrophy and highlights the role of Val and Ali as a promising therapeutic strategy for hypertension and LV hypertrophy.Â

Tissue Reactions to Various Suture Materials Used in Oral Surgical Interventions

A variety of suture materials are available for primary wound closure following oral surgical procedures. The aim was to review the tissue reactions to the various suture materials used in oral surgical interventions. Databases were searched using the following keywords: cotton, nylon, polyglecaprone 25, polytetrafluoroethylene (ePTFE), Polyglactin 910, polyglycolic acid (PGA), polylactic acid, silk, surgery, suture, and tissue reaction. Articles published only in English language were included. Seventeen studies were included. Two studies reported that polyglecaprone 25 had positive effects on wound-healing as compared to silk. Six studies reported that silk elicits more intense tissue inflammatory response and delayed wound healing as compared to other suture materials (including ePTFE, polyglecaprone-25, PGA, and nylon). Polyglactin 910 sutures were associated with the development of stitch abscess in one clinical study. Eight studies reported that tissue reactions are minimal with nylon sutures. Tissue reactions to suture materials used for oral surgical interventions may vary depending on the surface properties and bacterial adherence properties of the material