We report the synthesis of a soluble perylene imide benzimidazole (PIBI) and its structural, thermotropic, optical and electrochemical characterization with emphasis on discotic liquid crystalline ...properties.
In the present study we have synthesized a novel amphiphilic porphyrin and its Ag(II) complex through modification of water-soluble porphyrinic structure in order to increase its lipophilicity and in ...turn pharmacological potency. New cationic non-symmetrical meso-substituted porphyrins were characterized by UV–visible, electrospray ionization mass spectrometry (ESI-MS), 1H NMR techniques, lipophilicity (thin-layer chromatographic retention factor, Rf), and elemental analysis. The key toxicological profile (i.e. cytotoxicity and cell line- (cancer type-) specificity; genotoxicity; cell cycle effects) of amphiphilic Ag porphyrin was studied in human normal and cancer cell lines of various tissue origins and compared with its water-soluble analog. Structural modification of the molecule from water-soluble to amphiphilic resulted in a certain increase in the cytotoxicity and a decrease in cell line-specificity. Importantly, Ag(II) porphyrin showed less toxicity to normal cells and greater toxicity to their cancerous counterparts as compared to cisplatin. The amphiphilic complex was also not genotoxic and demonstrated a slight cytostatic effect via the cell cycle delay due to the prolongation of S-phase. As expected, the performed structural modification affected also the photocytotoxic activity of metal-free amphiphilic porphyrin. The ligand tested on cancer cell line revealed a dramatic (more than 70-fold) amplification of its phototoxic activity as compared to its water-soluble tetracationic metal-free analog. The compound combines low dark cytotoxicity with 5 fold stronger phototoxicity relative to Chlorin e6 and could be considered as a potential photosensitizer for further development in photodynamic therapy.
The cytotoxicity of amphiphilic Ag(II) porphyrin on various cancer and normal cells is presented and compared to that of cisplatin. Display omitted
Background: Armenia has trained physicians to practice family medicine (FM) for over 20 years. The pediatric population comprises a significant proportion of patients seen by FM practices, yet to ...date, there have been no studies assessing the knowledge and self-efficacy of FM physicians regarding pediatric care. As the first step is needs assessment to improve the quality of care, this study aims to assess the self-efficacy and knowledge of FM physicians regarding the care of pediatric patients. Materials and Methods: We distributed a survey to attendees at an FM conference in Lori Province, Armenia. The survey instrument assessed demographics and experience, self-efficacy in providing pediatric care, and pediatric knowledge via questions adapted from the American Board of Family Medicine (ABFM). Results: Eighty-seven percent of participants were female. Roughly half (45%) had trained through an FM residency program, while the remainder had retrained to become FM physicians following a residency in another field. Almost all (97%) practiced outside of the capital city, Yerevan. About half believed that their didactic (51%) and clinical education (48%) prepared them either "extremely" or "very" well. Overall, there was no clear relationship between participants' reported self-efficacy in a given area of pediatrics and their score in that area on the knowledge portion of the survey. Conclusions: Our findings reveal opportunities for improvement in knowledge related to pediatric care in FM physicians in Armenia, as well as a lack of relationship between reported self-efficacy and knowledge. Thus, future programs should not rely solely on self-reported gaps to identify or prioritize areas of focus. Further study is recommended in other specialties in Armenia and internationally to improve future programs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
In this paper we study the stability of fronts in a reduction of a well-known PDE system that is used to model the combustion in hydraulically resistant porous media. More precisely, we consider the ...original PDE system under the assumption that one of the parameters of the model, the Lewis number, is chosen in a specific way and with initial conditions of a specific form. For a class of initial conditions, then the number of unknown functions is reduced from three to two. For the reduced system, the existence of combustion fronts follows from the existence results for the original system. The stability of these fronts is studied here by a combination of energy estimates and numerical Evans function computations and nonlinear analysis when applicable. We then lift the restriction on the initial conditions and show that the stability results obtained for the reduced system extend to the fronts in the full system considered for that specific value of the Lewis number. The fronts that we investigate are proved to be either absolutely unstable or convectively unstable on the nonlinear level.
•We study the stability of fronts in a model of combustion in porous media.•We assume that the Lewis number is chosen in a specific way.•We use a combination of energy estimates and Evans function computations.•We prove nonlinear stability under the condition that there is no unstable spectrum.
BackgroundCOVID-19 infection has caused a global pandemic affecting a group of patients with chronic conditions including diabetes with exacerbating insulin resistance and hyperglycemia. ...Investigators noted that pre-existing diabetes and newly diagnosed diabetes are associated with an increased risk of all-cause mortality in hospitalized patients with COVID-19 infection.AimTo evaluate the relationship between ICU patients infected with COVID-19 and mortality among those with high versus low glucose levels.MethodsThis is a retrospective study of critically ill adult patients infected with COVID-19 who were admitted to the ICU from April 5, 2020, to October 14, 2020. The participants were from San Bernardino County which is a diverse and underserved community. Overall, 84 patients were included in the final analysis. The average age was 59.67 (standard deviation=15.55) with 59.5% being males. Overall mortality was 44.1%.ResultsAround one-fifth of patients had glucose under control as measured by peak glucose level of <180 mg/dL during hospital stay. A statistically significant association was seen between tighter serum glucose control and mortality (p=0.0354). Patients with serum glucose maintained <180 mg/dL were associated with significantly lower mortality than their counterparts (22.2% vs. 50%).ConclusionsThis study suggests that maintaining a tighter control of the glycemic index in critically ill COVID-19 patients will improve morbidity and mortality.
An Update to Hallmarks of Cancer Ravi, Swapna; Alencar, Jr, Antonio M; Arakelyan, Jemma ...
Curēus (Palo Alto, CA),
05/2022, Letnik:
14, Številka:
5
Journal Article
Recenzirano
Odprti dostop
In the last decade, there has been remarkable progress in research toward understanding and refining the hallmarks of cancer. In this review, we propose a new hallmark - "pro-survival autophagy." The ...importance of pro-survival autophagy is well established in tumorigenesis, as it is related to multiple steps in cancer progression and vital for some cancers. Autophagy is a potential anti-cancer therapeutic target. For this reason, autophagy is a good candidate as a new hallmark of cancer. We describe two enabling characteristics that play a major role in enabling cells to acquire the hallmarks of cancer - "tumor-promoting microenvironment and macroenvironment" and "cancer epigenetics, genome instability and mutation." We also discuss the recent updates, therapeutic and prognostic implications of the eight hallmarks of cancer described by Hanahan et al. in 2011. Understanding these hallmarks and enabling characteristics is key not only to developing new ways to treat cancer efficiently but also to exploring options to overcome cancer resistance to treatment.
Acute respiratory infections (ARIs) are major causes of morbidity in early childhood. They are mainly caused by viruses, including influenza (INF) and respiratory syncytial viruses (RSV). We aimed to ...investigate the role of RSV and INF in children hospitalized for ARIs and to show the impact of RSV/INF rapid testing on management of patients.
Cross-sectional study using data of inpatient care of children younger than five years hospitalized in Arabkir Medical Center due to ARI from November 1, 2013 to April 1, 2014. Nasopharyngeal swabs were tested for RSV and INF types A and B by direct antigen detection tests.
A total of 915 patients, 583 (63.7%) boys and 332 (36.3%) girls were included in the study with the mean age of 18.8 ± 16.3 months. Among them, 390 (42.6%) were tested positive, 3 (0.3%) subjects tested positive both for RSV and INF: 269 (29.4%) for RSV and 124 (13.6%) for INF (A - 121, B - 3). Out of 915 children, 209 (23%) were pretreated with antibiotics, most often with oral amoxicillin/clavulanic acid (n = 54, 25.8%), sulfamethoxazole/trimethoprim (n = 46, 22%), and amoxicillin (n = 38, 18.2%), followed by intramuscular ceftriaxone (n = 37, 17.7%).
The usage of antigen tests for detection of respiratory viruses allowed to document high rates of RSV and INF in children admitted to the hospital. In settings where polymerase chain reaction method is not readily available, implementation of rapid tests for detection of respiratory viruses is important in the management of pediatric patients including cohorting and more targeted use of antibiotics.
Drought is one of the most severe natural disasters with a high risk for human livelihoods. Remote sensing based drought indices can identify dry periods using, e.g., precipitation or vegetation ...information. Besides frequency, duration, and intensity, the timing of a drought onset and duration are important variables to measure the drought impact and risk. This article classifies drought events based on the timing of the drought and with regard to their impact on vegetation production during different crop growing stages. Drought and nondrought seasons are analyzed in Eastern Cape Province, South Africa. Here, the impact of a drought on vegetation production highly depends on the starting point and the duration of rainfall during the growing season. Weighted linear combination was applied based on vulnerable vegetation growing stages in the phenology to classify drought severity per season. Particularly the extreme drought season in 2015/2016 as well as the normal nondrought season in 2011/2012 was emphasized. The developed approach serves as input to quantify drought impact per cropping season from local to regional scales. Integration of socio-economic information can further complement this hazard information to support the quantification of the actual drought risk.
We consider an evolution model, in which the mutation rates depend on the structure of population: the mutation rates from lower populated sequences to higher populated sequences are reduced. We have ...applied the Hamilton–Jacobi equation method to solve the model and calculate the mean fitness. We have found that the modulated mutation rates, directed to increase the mean fitness.
•Most biological evolution models have constant mutation rates.•Here mutation rates from lower populated sequences to higher ones are reduced.•The calculated analytic results are confirmed by numerical solutions.•The model increases the heterogeneity and the mean fitness of the population.•The model can qualitatively explain some experimental results of a viral population.
PDF
