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Nimra Akram Naheed Khan Mehreen Ameen Shahmeera Mahmood Komal Shamim Marium Amin 《Chronobiology international》2013,30(9):1262-1268
ABSTRACTSeveral studies have focused on determining the effect of chronotype and learning approach on academic achievement separately indicating that morning types have an academic advantage over the evening types and so have the deep learners over the surface learners. But, surprisingly none have assessed the possible relationship between chronotype and learning approach. So, the current study aimed to evaluate this association and their individual influence on academic performance as indicated by the Cumulative Grade Point Average (CGPA) as well as the effect of their interaction on academic performance. The study included 345 undergraduate medical students who responded to reduced Morningness-Eveningness Questionnaire and Biggs Revised Two-Factor Study Process Questionnaire. Morning types indulged in deep learning while evening types in surface learning. Morning and evening types did not differ on academic performance but deep learners had better academic outcomes than their counterparts. The interaction between chronotype and learning approach was significant on determining academic achievement. Our findings gave the impression that chronotype could have an impact on academic performance not directly but indirectly through learning approaches. 相似文献
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Bashir Nabiha Ishfaq Mehreen Mazhar Kehkashan Khan Jahangir Sarwar Shahid Ramla 《Molecular biology reports》2022,49(1):487-495
Molecular Biology Reports - Biological treatment of many cancers currently targets membrane bound receptors located on a cell surface. We are in a great to need identify novel membrane proteins... 相似文献
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In the last two decades, 'concentrated epidemics' of human immunodeficiency virus (HIV) have established in several high risk groups in Pakistan, including Injecting Drug Users (IDUs) and among men who have sex with men (MSM). To explore the transmission patterns of HIV infection in these major high-risk groups of Pakistan, 76 HIV samples were analyzed from MSM, their female spouses and children, along with 26 samples from a previously studied cohort of IDUs. Phylogenetic analysis of HIV gag gene sequences obtained from these samples indicated a substantial degree of intermixing between the IDU and MSM populations, suggesting a bridging of HIV infection from IDUs, via MSM, to the MSM spouses and children. HIV epidemic in Pakistan is now spreading to the female spouses and offspring of bisexual MSM. HIV control and awareness programs must be refocused to include IDUs, MSM, as well as bisexual MSM, and their spouses and children. 相似文献
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Piptadenin,a Novel 3,4‐Secooleanane Triterpene and Piptadenamide,a New Ceramide from the Stem Bark of Piptadeniastrum africanum (Hook.f.) Brenan
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Amadou Dawé Marius Mbiantcha Yannick Fongang William Yosseu Nana Fawai Yakai Gilbert Ateufack Muhammad Ali Shaiq Iqbal Lubna Mehreen Lateef Bonaventure Tchaleu Ngadjui 《化学与生物多样性》2017,14(2)
Piptadenin ( 1 ), a new triterpene along with piptadenamide ( 10 ), a new ceramide, have been isolated from the AcOEt‐soluble fraction of the MeOH extract of the stem bark of Piptadeniastrum africanum along with nine known compounds, 1‐O‐[(3β,22β)‐3,22‐dihydroxy‐28‐oxoolean‐12‐en‐28‐yl]‐β‐d ‐glucopyranose ( 2 ), 22β‐hydroxyoleanic acid ( 3 ), oleanic acid ( 4 ), lupeol ( 5 ), betulinic acid ( 6 ), 5α‐stigmasta‐7,22‐dien‐3β‐ol ( 7 ), 5α‐stigmasta‐7,22‐dien‐3‐one ( 8 ), (3β)‐stigmast‐5‐en‐3‐yl β‐d ‐glucopyranoside ( 9 ) and 2,3‐dihydroxypropyl hexacosanoate ( 11 ). Except for compound 11 , all the isolated compounds are reported for the first time from this plant. The structures of the isolated compounds were elucidated by spectroscopic data including 1D and 2D NMR. The pure compounds 1 – 11 were subjected to the pharmacological screening and compounds 2 , 5 – 7 and 9 exhibited potent urease inhibitory activity with IC50 value of 25.8, 28.9, 30.1, 31.8 and 32.7 μm , respectively, whereas compound 1 showed moderate activity (IC50 = 98.7 μm ). The potent urease inhibitory activity supplemented the previous literature reports and medicinal uses of this plant. 相似文献
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Carlos C. Goller Mehreen Arshad James W. Noah Subramaniam Ananthan Carrie W. Evans N. Miranda Nebane Lynn Rasmussen Melinda Sosa Nichole A. Tower E. Lucile White Benjamin Neuenswander Patrick Porubsky Brooks E. Maki Steven A. Rogers Frank Schoenen Patrick C. Seed 《PloS one》2014,9(7)
Uropathogenic Escherichia coli (UPEC) is the leading cause of community-acquired urinary tract infections (UTIs), with over 100 million UTIs occurring annually throughout the world. Increasing antimicrobial resistance among UPEC limits ambulatory care options, delays effective treatment, and may increase overall morbidity and mortality from complications such as urosepsis. The polysaccharide capsules of UPEC are an attractive target a therapeutic, based on their importance in defense against the host immune responses; however, the large number of antigenic types has limited their incorporation into vaccine development. The objective of this study was to identify small-molecule inhibitors of UPEC capsule biogenesis. A large-scale screening effort entailing 338,740 compounds was conducted in a cell-based, phenotypic screen for inhibition of capsule biogenesis in UPEC. The primary and concentration-response assays yielded 29 putative inhibitors of capsule biogenesis, of which 6 were selected for further studies. Secondary confirmatory assays identified two highly active agents, named DU003 and DU011, with 50% inhibitory concentrations of 1.0 µM and 0.69 µM, respectively. Confirmatory assays for capsular antigen and biochemical measurement of capsular sugars verified the inhibitory action of both compounds and demonstrated minimal toxicity and off-target effects. Serum sensitivity assays demonstrated that both compounds produced significant bacterial death upon exposure to active human serum. DU011 administration in mice provided near complete protection against a lethal systemic infection with the prototypic UPEC K1 isolate UTI89. This work has provided a conceptually new class of molecules to combat UPEC infection, and future studies will establish the molecular basis for their action along with efficacy in UTI and other UPEC infections. 相似文献
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Chang-Hoon Choi Peter A. Thomason Mehreen Zaki Robert H. Insall Diane L. Barber 《The Journal of biological chemistry》2013,288(4):2464-2474
Phosphorylation of the actin-related protein 2 (Arp2) subunit of the Arp2/3 complex on evolutionarily conserved threonine and tyrosine residues was recently identified and shown to be necessary for nucleating activity of the Arp2/3 complex and membrane protrusion of Drosophila cells. Here we use the Dictyostelium diploid system to replace the essential Arp2 protein with mutants that cannot be phosphorylated at Thr-235/6 and Tyr-200. We found that aggregation of the resulting mutant cells after starvation was substantially slowed with delayed early developmental gene expression and that chemotaxis toward a cAMP gradient was defective with loss of polarity and attenuated F-actin assembly. Chemotaxis toward cAMP was also diminished with reduced cell speed and directionality and shorter pseudopod lifetime when Arp2 phosphorylation mutant cells were allowed to develop longer to a responsive state similar to that of wild-type cells. However, clathrin-mediated endocytosis and chemotaxis under agar to folate in vegetative cells were only subtly affected in Arp2 phosphorylation mutants. Thus, phosphorylation of threonine and tyrosine is important for a subset of the functions of the Arp2/3 complex, in particular an unexpected major role in regulating development. 相似文献
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Background
Morbidity associated with primary headache disorders is a major public health problem with an overall prevalence of 46%. Tension-type headache and migraine are the two most prevalent causes. However, headache has not been sufficiently studied as a cause of morbidity in the developing world. Literature on prevalence and classification of these disorders in South Asia is scarce. The aim of this study is to describe the classification and clinical features of headache patients who seek medical advice in Pakistan.Methods and Results
Medical records of 255 consecutive patients who presented to a headache clinic at a tertiary care hospital were reviewed. Demographic details, onset and lifetime duration of illness, pattern of headache, associated features and family history were recorded. International Classification of Headache Disorders version 2 was applied.66% of all patients were women and 81% of them were between 16 and 49 years of age. Migraine was the most common disorder (206 patients) followed by tension-type headache (58 patients), medication-overuse headache (6 patients) and cluster headache (4 patients). Chronic daily headache was seen in 99 patients. Patients with tension-type headache suffered from more frequent episodes of headache than patients with migraine (p<0.001). Duration of each headache episode was higher in women with menstrually related migraine (p = 0.015). Median age at presentation and at onset was lower in patients with migraine who reported a first-degree family history of the disease (p = 0.003 and p<0.001 respectively).Conclusions/Significance
Patients who seek medical advice for headache in Pakistan are usually in their most productive ages. Migraine and tension-type headache are the most common clinical presentations of headache. Onset of migraine is earlier in patients with first-degree family history. Menstrually related migraine affects women with headache episodes of longer duration than other patients and it warrants special therapeutic consideration. Follow-up studies to describe epidemiology and burden of headache in Pakistan are needed. 相似文献10.
The Patterson F- and D-statistics are commonly used measures for quantifying population relationships and for testing hypotheses about demographic history. These statistics make use of allele frequency information across populations to infer different aspects of population history, such as population structure and introgression events. Inclusion of related or inbred individuals can bias such statistics, which may often lead to the filtering of such individuals. Here, we derive statistical properties of the F- and D-statistics, including their biases due to the inclusion of related or inbred individuals, their variances, and their corresponding mean squared errors. Moreover, for those statistics that are biased, we develop unbiased estimators and evaluate the variances of these new quantities. Comparisons of the new unbiased statistics to the originals demonstrates that our newly derived statistics often have lower error across a wide population parameter space. Furthermore, we apply these unbiased estimators using several global human populations with the inclusion of related individuals to highlight their application on an empirical dataset. Finally, we implement these unbiased estimators in open-source software package funbiased for easy application by the scientific community. 相似文献