694 research outputs found

    Electron dynamics in InNxSb1–x

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    Electron transport properties in InNxSb1–x are investigated for a range of alloy compositions. The band structure of InNxSb1–x is modeled using a modified k·p Hamiltonian. This enables the semiconductor statistics for a given x value to be calculated from the dispersion relation of the E– subband. These calculations reveal that for alloy compositions in the range 0.001<=x<=0.02 there is only a small variation of the carrier concentration at a given plasma frequency. A similar trend is observed for the effective mass at the Fermi level. Measurements of the plasma frequency and plasmon lifetime for InNxSb1–x alloys enable the carrier concentration and the effective mass at the Fermi level to be determined and a lower limit for the electron mobility to be estimated

    The quest for better outcomes: a randomized controlled trial comparing letrozole versus clomiphene citrate in polycystic ovarian syndrome related infertility

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    Background: Infertility is a widespread concern, particularly among individuals with polycystic ovarian syndrome (PCOS). Clomiphene citrate (CC) has been a primary treatment for PCOS-related infertility, despite suboptimal pregnancy rates. Letrozole, an aromatase inhibitor, presents an alternative with potential advantages for improving pregnancy outcomes. This study aimed to rigorously compare letrozole and CC in the context of PCOS-related infertility, focusing on Bangladeshi women, adopting incremental dosing protocols, and examining endpoints to contribute valuable insights. Methods: A randomized controlled trial was conducted at a tertiary care center in Bangladesh from July 2021 to June 2023. Participants included women aged 18-35 with anovulatory infertility due to PCOS. They were randomized into two groups: letrozole and CC. Treatments were administered following incremental dosing protocols, and outcomes included endometrial thickness, ovulation rate, mono-follicular development, pregnancy rate, and time to pregnancy. Results: Out of 187 patients assessed for eligibility, 102 were enrolled, with 51 in each group. Demographics were comparable between groups. While endometrial thickness did not significantly differ between the groups, letrozole demonstrated a higher rate of mono-follicular development (72.55% versus 50.98%), a significantly higher pregnancy rate (47.06% versus 23.53%), and a shorter time to pregnancy (9.23 weeks versus 11.7 weeks) compared to CC. Conclusions: This study suggests that letrozole may be a preferred option for ovulation induction in PCOS patients due to its superior pregnancy rates and shorter time to pregnancy compared to CC. However, limitations such as a relatively small sample size and variations in dosages should be considered. Further research is needed to validate these findings and address the evolving needs of patients with PCOS-related infertility

    Effects of Seasonal Precipitation on the Amount of Seepage-A Case Study of Tunnel 3 of Bazai Irrigation Project Khyber Pakhtunkhwa

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    Infiltration of water into tunnel within a harsh geological formation is a vital issue in tunnelling. The consequence impacts due to seepage include tunnel rock instability, pore-water pressure imposition and diminution of operational capacity. The spatial variation in rainfall due to climate change intensifies the threat to tunnel stability. Likewise, to understand the impacts of climate change scenarios on the seepage of tunnel 3 of the Bazai irrigation project was numerically simulated in SEEP/W software by manipulating the rainfall data. The net annual precipitation is followed by two sets of rainfall data i.e., dry and wet season precipitation depending upon the magnitude of rainfall. The analysis revealed that most of the seepage occurred in the unlined portion. In order to determine the future impacts of precipitation on seepage quantity, the wet season precipitation was further increased by 10% and 50% for A1B and B2 conditions respectively. The seepage quantity into the tunnel increases with variation in precipitation patterns. To reduce the risk to tunnel stability, the model was also treated with cement-bentonite grout and bentonite slurry containing 6% solids. The performance of both grouting techniques leads to noticeable seepage deduction. The study further suggests that cement-bentonite is more effective in seepage remediation

    Rapamycin inhibition of baculovirus recombinant (BVr) ribosomal protein S6 kinase (S6K1) is mediated by an event other than phosphorylation

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    <p>Abstract</p> <p>Background</p> <p>Ribosomal protein S6 kinase 1(S6K1) is an evolutionary conserved kinase that is activated in response to growth factors and viral stimuli to influence cellular growth and proliferation. This downstream effector of target of rapamycin (TOR) signaling cascade is known to be directly activated by TOR- kinase mediated hydrophobic motif (HM) phosphorylation at Threonine 412 (T412). Selective loss of this phosphorylation by inactivation of TOR kinase or activation/recruitment of a phosphatase has accordingly been implicated in mediating inhibition by rapamycin.</p> <p>Findings</p> <p>We present evidence that baculovirus driven expression of S6K1 in insect cells (Sf9) fails to activate the enzyme and instead renders it modestly active representing 4-6 folds less activity than its fully active mammalian counterpart. Contrary to the contention that viral infection activates TOR signaling pathway, we report that BVr enzyme fails to exhibit putative TOR dependent phosphorylation at the HM and the resultant phosphorylation at the activation loop (AL) of the enzyme, correlating with the level of activity observed. Surprisingly, the BVr enzyme continued to exhibit sensitivity to rapamycin that remained unaffected by mutations compromised for TOR phosphorylation (T412A) or deletions compromised for TOR binding (ΔNH <sub>2-46</sub>/ΔCT<sub>104</sub>).</p> <p>Conclusions</p> <p>These data together with the ability of the BVr enzyme to resist inactivation by phosphatases indicate that inhibition by rapamycin is not mediated by any phosphorylation event in general and TOR dependent phosphorylation in particular.</p

    Interaction of palmitic acid with losartan potassium at the binding sites of bovine serum albumin

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    The binding of losartan potassium, an angiotensin II receptor antagonist, to bovine serum albumin was studied by equilibrium dialysis method (ED) in presence or absence of palmitic acid. The study was carried out using ranitidine and diazepam as site-1 and site-2 specific probe, respectively. Different analysis of binding of losartan to bovine serum albumin suggested two sets of association constants: high affinity association constant (k1 = 11.2 x 105 M-1) with low capacity (n1 = 2) and low affinity association (k2 = 2. 63 x 105 M-1) constant with high capacity (n2 = 10) at pH 7.4 and 27°C. During concurrent administration of palmitic acid and losartan potassium in presence or absence of ranitidine or diazepam, it was that found that palmitic acid causes the release of losartan potassium from its binding site on BSA resulting reduced binding of losartan potassium to BSA. The increment in free fraction of losartan potassium was from 13.1% to 47.2 % upon the addition of increased concentration of only palmitic acid at a concentration of 0 x 10-5 M to 16 x 10-5 M. In presence of ranitidine or diazepam as site specific probes, palmitic acid further increases the free fraction of losartan potassium were from 22.8% to 53.4% and 35.3 to 65.5%, respectively. This data provided the evidence of interaction of higher concentration of palmitic acid at the binding sites on BSA changing the pharmacokinetics properties of losartan potassium
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