2,171 research outputs found
Quantum initial condition sampling for linearized density matrix dynamics: Vibrational pure dephasing of iodine in krypton matrices
This paper reviews the linearized path integral approach for computing time
dependent properties of systems that can be approximated using a mixed
quantum-classical description. This approach is applied to studying vibrational
pure dephasing of ground state molecular iodine in a rare gas matrix. The
Feynman-Kleinert optimized harmonic approximation for the full system density
operator is used to sample initial conditions for the bath degrees of freedom.
This extremely efficient approach is compared with alternative initial
condition sampling techniques at low temperatures where classical initial
condition sampling yields dephasing rates that are nearly an order of magnitude
too slow compared with quantum initial condition sampling and experimental
results.Comment: 20 pages and 8 figure
VALIDITY OF THE POWERLINE BOAT INSTRUMENTATION SYSTEM
The PowerLine Boat Instrumentation System3 is comprised of instrumented oarlocks capable of measuring pin forces in the direction of boat travel and oarlock angles. The aim of this study was to determine the reliability and validity of the force and angle data from the PowerLine Boat Instrumentation System in a laboratory setting. Data were collected with the sculling oarlocks affixed to a horizontally aligned, stabilised wing rigger. For force analysis, signals were collected at 50 Hz from both the PowerLine system and a 1 kN load cell4 during 10 repetitions at a rate of approximately 30 repetitions per minute. For angular analysis, whilst recording with PowerLine, oarlocks were repositioned for a minimum of two seconds at known angles in a random order using an inclinometer accurate to one tenth of a degree over a range of -80° to +60°, in 20° increments. Linear regression analysis through the origin was used to compare the PowerLine values with known values from the load cell and the inclinometer. Laboratory testing proved the force and angle sensors to be valid throughout the testing range (0 N to 554.8 + 20.4 N, and -80° to +60° respectively) when fully functioning. The PowerLine Boat Instrumentation System appears to be appropriate for measuring biomechanical variables in an elite sculling programme. On-water reliability testing is still required to fully evaluate their application in quantifying the effect of interventions made to technique or boat set-up
Physicochemical properties and lubricant potentials of Blighia sapida Sapindaceaeae seed oil in solid dosage formulations
Purpose: To investigate and compare the physicochemical properties and lubricant potentials of Blighia sapida seed oil (BSSO) with those of magnesium stearate, a commercial lubricant.Methods: The dried seeds of Blighia sapida (BS) powder were macerated with n-hexane for five days to separate the oil. The physicochemical properties; solubility profile, acid value, saponification value, iodine value of the oil were determined using standard methods. Batches of ascorbic acid tablets compressed at same compression settings using different concentrations of BSSO as lubricant were evaluated for their friability, weight uniformity, tablet hardness, disintegration and dissolution.Results: BSSO had a density of 0.9 g/ml, acid value of 2.65 ± 0.20 mg KOH/g, saponification value of 141.65 ± 0.75 mg KOH/g, iodine value of 62.50 ±3.71 mg I2/g among other parameters. Fatty acid methyl ester analysis (FAME) revealed 96.89 % of monounsaturated fatty acids and esters in the range of C15-C23; a C23 compound, 22-tricosenoic acid was the dominant compound (46.82 %). The oil showed excellent lubrication properties in ascorbic acid tablets at a low concentration (0.5 %), similar to 2 % magnesium stearate. However, higher concentration (5 %) of BSSO resulted in granules that could not be compressed into tablets. Tablets containing BSSO demonstrated satisfactory friability, weight uniformity, hardness, disintegration and dissolution characteristics.Conclusion: Blighia sapida seed oil is a potentially useful low-cost tablet lubricant. However, further investigations on the excipient, including stability, toxicity, etc, are required to ascertain its suitability.Keywords: Blighia sapida, Lubricants, Seed oil, Excipients, Ascorbic acid, Tablet properties, 22- Tricosenoic aci
The Use of Plant Steroids in Viral Disease Treatments: Current Status and Future Perspectives
Plants have been used for the prevention and treatment of diseases since the early days of humankind and constitute the natural sources of today’s modern medicine. Approximately one-quarter of approved drugs are derived from plants. Plant steroids are a group of biologically active secondary metabolites with a 5α and 5β gonane carbon skeleton. There is immense chemical diversity in plant steroids due to the side chains, oxidation status of the carbons in the tetracyclic core, and methyl groups. Plant steroids are classified into several groups based on their biological functions and structures, also on their mechanism of biosynthesis. All subtypes have been investigated for their anti-cancer, immunomodulatory, antiinflammatory, and anti-viral properties. The novel coronavirus disease (COVID-19) is caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2), which carries an RNA genome. An intense effort has been made in terms of effective treatment strategies and vaccine development since it was declared a pandemic. Nucleoside analogs such as favipiravir and remdesivir are used to block RNA-dependent RNA polymerase enzymes. Other strategies including neuraminidase inhibitors, chloroquine, and hydroxychloroquine as immunomodulatory agents, stem cell and cytokine-based therapies are being conducted. One part of the therapies against SARS-CoV-2 is focused on the spike (S) protein of the virus that binds to the host receptor, angiotensin-converting enzyme 2 (ACE2). It has been suggested that SARS-CoV-2 S protein has a free fatty acidbinding pocket, and according to molecular simulations, steroids are ligands that bind to this pocket. Therefore, this review summarizes the plant steroid biological actions as well as their anti-viral potential against SARS-CoV-2 infection
Pandemic influenza control in Europe and the constraints resulting from incoherent public health laws
© 2010 Martin et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: With the emergence of influenza H1N1v the world is facing its first 21st century global pandemic. Severe Acute Respiratory Syndrome (SARS) and avian influenza H5N1 prompted development of pandemic preparedness plans. National systems of public health law are essential for public health stewardship and for the implementation of public health policy[1]. International coherence will contribute to effective regional and global responses. However little research has been undertaken on how law works as a tool for disease control in Europe. With co-funding from the European Union, we investigated the extent to which laws across Europe support or constrain pandemic preparedness planning, and whether national differences are likely to constrain control efforts. Methods: We undertook a survey of national public health laws across 32 European states using a questionnaire designed around a disease scenario based on pandemic influenza. Questionnaire results were reviewed in workshops, analysing how differences between national laws might support or hinder regional responses to pandemic influenza. Respondents examined the impact of national laws on the movements of information, goods, services and people across borders in a time of pandemic, the capacity for surveillance, case detection, case management and community control, the deployment of strategies of prevention, containment, mitigation and recovery and the identification of commonalities and disconnects across states. Results: Results of this study show differences across Europe in the extent to which national pandemic policy and pandemic plans have been integrated with public health laws. We found significant differences in legislation and in the legitimacy of strategic plans. States differ in the range and the nature of intervention measures authorized by law, the extent to which borders could be closed to movement of persons and goods during a pandemic, and access to healthcare of non-resident persons. Some states propose use of emergency powers that might potentially override human rights protections while other states propose to limit interventions to those authorized by public health laws. Conclusion: These differences could create problems for European strategies if an evolving influenza pandemic results in more serious public health challenges or, indeed, if a novel disease other than influenza emerges with pandemic potential. There is insufficient understanding across Europe of the role and importance of law in pandemic planning. States need to build capacity in public health law to support disease prevention and control policies. Our research suggests that states would welcome further guidance from the EU on management of a pandemic, and guidance to assist in greater commonality of legal approaches across states.Peer reviewe
Specific c-Jun N-Terminal Kinase Inhibitor, JNK-IN-8 Suppresses Mesenchymal Profile of PTX-Resistant MCF-7 Cells through Modulating PI3K/Akt, MAPK and Wnt Signaling Pathways
Paclitaxel (PTX) is a widely used chemotherapeutic agent in the treatment of breast cancer, and resistance to PTX is a common failure of breast cancer therapy. Therefore, understanding the effective molecular targets in PTX-resistance gains importance in identifying novel strategies in successful breast cancer therapy approaches. The aim of the study was to investigate the functional role of PTX resistance on MCF-7 cell survival and proliferation related to PI3K/Akt and MAPK pathways. The generated PTX-resistant (PTX-res) MCF-7 cells showed enhanced cell survival, proliferation, and colony formation potential with decreased cell death compared to wt MCF-7 cells. PTX-res MCF-7 cells exhibited increased motility profile with EMT, PI3K/Akt, and MAPK pathway induction. According to the significant SAPK/JNK activation in PTX-res MCF-7 cells, specific c-Jun N-terminal kinase inhibitor, JNK-IN-8 is shown to suppress the migration potential of cells. Treatment of JNK inhibitor suppressed the p38 and SAPK/JNK and Vimentin expression. However, the JNK inhibitor further downregulated Wnt signaling members in PTX-res MCF-7 cells. Therefore, the JNK inhibitor JNK-IN-8 might be used as a potential therapy model to reverse PTX-resistance related to Wnt signaling
AMPK Is the Crucial Target for the CDK4/6 Inhibitors Mediated Therapeutic Responses in PANC-1 and MIA PaCa-2 Pancreatic Cancer Cell Lines
The survival rate of pancreatic ductal adenocarcinoma (PDAC) patients is short, and PDAC is a cancer type that ranks fourth in the statistics regarding death due to cancer. Mutation in the KRAS gene, which plays a role in pancreatic cancer development, activates the PI3K/AKT/mTOR signaling pathway. The activity of the AMPK as a cellular energy sensor is one of the fundamental mechanisms that can induce effective therapeutic responses against CDK4/6 inhibitors via adjusting the cellular and tumor microenvironment stress management. The phosphorylation of AMPKα at the different phosphorylation residues such as Thr172 and Ser 377 causes metabolic differentiation in the cells following CDK4/6 inhibitor treatment in accordance with an increased cell cycle arrest and senescence under the control of different cellular players. In this study, we examined the competencies of the CDK4/6 inhibitors LY2835219 and PD-0332991 on the mechanism of cell survival and death based on AMPK signaling. Both CDK4/6 inhibitors LY2835219 and PD-0332991 modulated different molecular players on the PI3K/AKT/mTOR and AMPK signaling axis in different ways to reduce cell survival in a cell type dependent manner. These drugs are potential inducers of apoptosis and senescence that can alter the therapeutic efficacy cells
Gene expression correlates of social evolution in coral reef butterflyfishes
Animals display remarkable variation in social behaviour. However, outside of rodents, little is known about the neural mechanisms of social variation, and whether they are shared across species and sexes, limiting our understand- ing of how sociality evolves. Using coral reef butterflyfishes, we examined gene expression correlates of social variation (i.e. pair bonding versus solitary living) within and between species and sexes. In several brain regions, we quantified gene expression of receptors important for social variation in mammals: oxytocin (OTR), arginine vasopressin (V1aR), dopamine (D1R, D2R) and mu-opioid (MOR). We found that social variation across individuals of the oval butterflyfish, Chaetodon lunulatus, is linked to differences in OTR, V1aR, D1R, D2R and MOR gene expression within several forebrain regions in a sexually dimorphic manner. However, this contrasted with social variation among six species representing a single evolutionary transition from pair- bonded to solitary living. Here, OTR expression within the supracommissural part of the ventral telencephalon was higher in pair-bonded than solitary species, specifically in males. These results contribute to the emerging idea that nonapeptide, dopamine and opioid signalling is a central theme to the evolution of sociality across individuals, although the precise mechanism may be flexible across sexes and species
Violence against Women Raises Risk of Cervical Cancer
Background: An emerging literature suggests that violence against women (VAW), particularly sexual violence, may increase the risk of acquiring a sexually transmitted infection (STI) and, therefore, may be associated with cervical cancer development. The purpose of this cross-sectional analysis was to determine if women who had experienced violence had higher prevalence rates of invasive cervical cancer.
Methods: Women aged 18–88 who joined the Kentucky Women’s Health Registry (2006–2007) and completed a questionnaire were included in the sample. Multivariate logistic regression analyses were used to adjust odds ratio (OR) for confounders (e.g., age, education, current marital status, lifetime illegal drug use, and pack-years of cigarette smoking).
Results: Of 4732 participants with no missing data on violence, cervical cancer, or demographic factors, 103 (2.1%) reported ever having cervical cancer. Adjusting for demographic factors, smoking, and illegal drug use, experiencing VAW was associated with an increased prevalence of invasive cervical cancer (adjusted OR [aOR]¼2.6, 95% CI¼1.7-3.9). This association remained significant when looking at three specific types of VAW: intimate partner violence (IPV) (aOR¼2.7, 95% CI¼1.8-4.0), adult exposure to forced sex (aOR¼2.6, 95% CI¼1.6-4.3), and child exposure to sexual abuse (aOR¼2.4, 95% CI¼1.4-4.0).
Conclusions: Rates of cervical cancer were highest for those experiencing all three types of VAW relative to those never experiencing VAW. Because VAW is common and has gynecological health effects, asking about VAW in healthcare settings and using this information to provide tailored healthcare may improve women’s health outcomes
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