1,851 research outputs found
Chronic Arsenic Exposure in Nanomolar Concentrations Accelerates Senescent Phenotypes in vitro
Arsenic is recognized as an environmental carcinogen, in which over 100 million individuals worldwide experience chronic exposure through contaminated drinking water. Arsenic exposure is linked to several health conditions, such as cancer, diabetes, skin lesions, immune dysfunction, and cardiovascular disease. Here we test the hypothesis that toxicants, such as arsenic, accelerate the program of senescence. Human (IMR-90) primary diploid fibroblasts were chronically exposed to arsenic at nanomolar concentrations and the impact on the expression of senescent-associated mRNAs was evaluated. IMR-90 cells were exposed either to untreated media or exposed to 130nM and 330nM AsCl3 supplemented media. RNA samples were extracted weekly from IMR-90 cells and RTPCR was conducted. Arsenic-exposed IMR-90 cells displayed increases in all senescence-associated transcripts monitored, those include Interleukin-6, Interleukin-8, Interleukin-alpha and the cyclin-dependent kinase inhibitor protein P16. At day 40, post AsCl3 exposure, a near 25-100 fold increase in senescent transcript expression was observed. Thus, there appears to be a direct relationship between the duration of toxicant stress, and the increased transcription level of senescent transcripts. Our studies suggest that low dose AsCl3 exposure promotes senescent transcript expression and very likely accelerates the senescent program that has the penitential of creating a cellular niche that is permissive to disease progression
Compendium of NASA Langley reports on hypersonic aerodynamics
Reference is made to papers published by the Langley Research Center in various areas of hypersonic aerodynamics for the period 1950 to 1986. The research work was performed either in-house by the Center staff or by other personnel supported entirely or in part by grants or contracts. Abstracts have been included with the references when available. The references are listed chronologically and are grouped under the following general headings: (1) Aerodynamic Measurements - Single Shapes; (2) Aerodynamic Measurements - Configurations; (3) Aero-Heating; (4) Configuration Studies; (5) Propulsion Integration Experiment; (6) Propulsion Integration - Study; (7) Analysis Methods; (8) Test Techniques; and (9) Airframe Active Cooling Systems
Graphical representation of an error occuring in linear system solution
U članku se razmatra problem pogreške u rješenju sustava linearnih jednadžbi koja nastaje zbog promjene desne strane sustava. Za ilustraciju tog problema koriste se mogućnosti programskog paketa Mathematica.The paper considers the problem of an error in
solving a linear system, which occurs due to a change of the
system right-hand side. This problem is graphically illustrated by
the Mathematica software package
Hybridizing two-step growth mixture model and exploratory factor analysis to examine heterogeneity in nonlinear trajectories
Empirical researchers are usually interested in investigating the impacts of
baseline covariates have when uncovering sample heterogeneity and separating
samples into more homogeneous groups. However, a considerable number of studies
in the structural equation modeling (SEM) framework usually start with vague
hypotheses in terms of heterogeneity and possible reasons. It suggests that (1)
the determination and specification of a proper model with covariates is not
straightforward, and (2) the exploration process may be computational intensive
given that a model in the SEM framework is usually complicated and the pool of
candidate covariates is usually huge in the psychological and educational
domain where the SEM framework is widely employed. Following
\citet{Bakk2017two}, this article presents a two-step growth mixture model
(GMM) that examines the relationship between latent classes of nonlinear
trajectories and baseline characteristics. Our simulation studies demonstrate
that the proposed model is capable of clustering the nonlinear change patterns,
and estimating the parameters of interest unbiasedly, precisely, as well as
exhibiting appropriate confidence interval coverage. Considering the pool of
candidate covariates is usually huge and highly correlated, this study also
proposes implementing exploratory factor analysis (EFA) to reduce the dimension
of covariate space. We illustrate how to use the hybrid method, the two-step
GMM and EFA, to efficiently explore the heterogeneity of nonlinear trajectories
of longitudinal mathematics achievement data.Comment: Draft version 1.6, 08/08/2020. This paper has not been peer reviewed.
Please do not copy or cite without author's permissio
PENGARUH PEMBERIAN AIR PERASAN DALIN PEPAYA PADA AYAM: II. RESPON PATOFISIOLOGIK HEPAR = THE EFFECTS OF PAPAYA LEAF EXTRACT ON CHICKENS: II. PATHOPHYSIOLOGIC AL CHANGES OF LIVER
Penelitian ini bertujuan untuk melihat pengaruh pemberian air perasan dam pepaya dengan berbagai tingkatan dosis terhadap respon patofisiologik hepar ayam buras. Penelitian menggunakan 20 ekor ayam buras yang berumur 3 bulan dengan berat badan rata-rata (± SD) adalah 577 ± 69,97 gram. Hewan percobaan dikelompokkan secara acak merata dalam lima kelompok perlakuan, tiap-tiap kelompok terdiri dari empat ekor. Kelompok pertama sebagai kontrol hanya diberikan aquades (P0)kelompok kedua sampai kelompok lima diberi air perasaan daun pepaya dosis tunggal sebagai berikut: 1,5 ml (P1), 2,0 ml (P2), 2,5 nil (P3) dan 3,0 ml (P4). Untuk pembuatan perasan daun pepaya digunakan 400 g daun pepaya yang diekstraksi secara sederhana. Empat hturi setelab perlakuan ayam dikorbankan, dinekropsi dan dilakukan pemeriksaan hepar. Pemeriksaan dilakukan secara makroskopik dan mikroskopik. Preparat mikroskopik dibuat dengan metode parafin dan diwarnai dengan hematoksilineosin (HE). Hasil penelitian menunjukkan perubahan patologik pada hepar pada kelompok perlakuan P2 P3 dan P4. Secara makroskopik pada hepar terlihat membengkak dan hiperemik, sedangkan secara mikroskopik struktur hepatositus teijadi degenerasi dengan gambaran inti pucat, hiperemi, hemoragi, dan koloni sel polimorfonuklear. Pada kelompok Po dan Pl tidak terlihat adanya perubahan makroskopik dan mikroskopik pada hepar ayam. Dari basil penelitian dapat disimpulkan bahwa dosis air perasan daun papaya 1,5 ml tidak menimbulkan perubahan patofisiologik, sedangkan pemberian pada dosis 2,0 nil, 2,5 ml dan 3,0 mi memperlihatkan perubahan patofisiologik pada hepar ayam buras. Semakin tinggi dosis pemberian air perasan daun pepaya yang diberikan pada ayam semakin besar perubahannya.
Kata kunci: Air perasan daun pepayapatofisiologik hepa
INDUSTRIAL RELATIONS ENVIRONMENT IN NIGERIA: REVIEWING CONFLICT CAUSES AND TAXANOMIES AMONG PUBLIC SECTOR EMPLOYEES
The institutional and legal framework of bargaining that has been established in Nigeria can be seen as encapsulating the shape, rather than the substance, of meaningful industrial relations. As such, it closely corresponds to the broader disagreement existing in other areas of social life between the constitutional, legal, and normative mores inherited from the colonial government and real behavior patterns. The main issues that divide wage earners, on the one hand, from employers and government, on the other, have an existence far alienated from the recognized system of industrial relations, while the unions, the employers, and the government continue to give formal adherence to the system. As a response to the need to resolve issues between employers and their workers speedily, the Industrial Arbitration Panel [IAP] was established in 1976. The Act which was established vested the Panel with jurisdiction to hear and determine trade disputes between workers and employers, including inter and intra Union disputes in both private and public sectors of Nigeria. The paper seeks to review the industrial relations environment in Nigeria. It emphasizes on how conflict and its taxonomies shapes the behavior of public sector employees. The paper equally concludes that the causes of conflict among public sector employees is greatly influenced by the inter-play of institutional, political and legal factors within the industrial relations environment. Article visualizations
Relationship Between Stages of Change and HPV Vaccine Attitudes and Beliefs in Baccalaureate Nursing Students
The purpose of this study was to: (a) determine if there is a relationship between attitudes/beliefs about Human papillomavirus (HPV) vaccination and stages of change and (b) investigate gender differences in attitudes/beliefs and stages of change in undergraduate baccalaureate nursing students. The study employs a cross-sectional and descriptive correlational design and it was guided by the Trans-theoretical Model of Change (TMC). The convenience sample was comprised of 131 participants at a large urban public university in Midwest United States. Data were collected with online surveys distributed via university email. A positive, moderate relationship was found between HPV vaccination attitudes/beliefs and stage of change (r=.36, p\u3c.001). Attitudes/beliefs and readiness to change were measured using multiple regression. An independent t-test was used to determine difference in male and female mean belief and attitude scores. Results show that those with more favorable attitudes/beliefs about HPV vaccination, as well as those who felt supported by others regarding obtaining the vaccine, were more likely to either be in the process of getting vaccinated or had already been vaccinated. Also, although there is no statistical difference in attitudes/beliefs about the HPV vaccine between males and females, males were less likely to have made efforts to be vaccinated compared with females (t= -2.99, p=.003). Therefore, it is possible that there is a gender disparity in knowledge about the vaccine or how to obtain it. The findings warrant further investigation as to what prevents males from being vaccinated
Novel paradigm for immunotherapy of breast cancer by engaging prophylactic immunity against hepatitis B
Background
Immunotherapy of patients suffering from the human epidermal growth factor receptor 2 overexpressing (HER-2+) breast cancers with the anti-HER-2 antibodies results in increase of the patients’ overall survival. However, no prophylactic vaccine is available against HER-2+ breast cancers. Although, prophylactic vaccine for human hepatitis B virus (HBV) is very effective.
Specific aim
The specific aim of this work was to design, synthesize, and test bio-molecules which would engage prophylactic immunity against hepatitis B virus towards killing breast cancers cells.
Methods and Results
By biomolecular engineering, we have created a novel family of biomolecules: antibody (anti-HER-2) × vaccine (HBsAg) engineered constructs (AVEC: anti-HER-2 × HBsAg). These biomolecules were utilized for redirecting, accelerating, and amplifying of the vaccination-induced, prophylactic immunity originally targeted against HBV as therapeutic immunity, newly targeted against HER-2+ breast cancers. Treatment of the HER-2+ breast cancer cells with AVEC: anti-HER-2 × HBsAg in blood of the patients, vaccinated with HBsAg, rapidly increased efficacy of killing of HER-2+ breast cancer cells over that attained with the naked anti-HER-2 antibodies.
Conclusion
Novel antibody-vaccine engineered constructs (AVEC) facilitate redirecting, accelerating, and amplifying of prophylactic, HBV vaccination-induced immunity as immunotherapy (RAAVIIT) of HER-2+ breast cancer. We currently streamline this novel therapeutic paradigm into clinical trials of breast and other cancers
Suitability of viscosity measurement methods for liquid food variety and applicability in food industry - A review.
Although there are several approaches to measure viscosity of liquid foods in the literature, the successful selected technique depends on the specific product and the functional characteristics that need to be analyzed. Accordingly, it is not an easy task for food technologists to determine the suitable approach to be used. Therefore briefing the existing methods, working principles, advantages, limitations and their successful applications for well known published articles, may enable the researchers to choose the optimum approach. The intensive review revealed that the most commonly used viscosity measurement devices are capillary flow viscometers, orifice type viscometers, falling ball viscometers, and rotational viscometers. Glass capillary viscometers are widely used for measuring low to medium viscosity of Newtonian fluids. In order to measure the viscosity of difficult fluids like those having large particles non-conventional geometries such as mixer viscometry method is used. Tube viscometer method which might be considered as a wide-bore capillary viscometer with a special capability to handle suspensions is currently used to determine rheological behaviour of a product after a thermal treatment. Scraped surface heat exchangers (SSHE) are widely used in food industry for thermal treatment of very viscous food products. Mass detecting capillary viscometer is a new technique to measure the viscosity of milk and soymilk products. In order to measure the viscosity of food stabilizers coaxial viscometers are recommended. Also, possibly the best known of the orifice viscometers in the food industry is the dipping-type Zahn viscometer. Finally, it could be inferred that the viscosity ought to be independent on the instrument, so different instruments will yield the same results, but this is a theoretical concept and different instruments rarely yield identical results
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