Colistin is an effective antibiotic for treatment of most multidrug-resistant Gram-negative bacteria. It is used currently as a last-line drug for infections due to severe Gram-negative bacteria ...followed by an increase in resistance among Gram-negative bacteria. Colistin resistance is considered a serious problem, due to a lack of alternative antibiotics. Some bacteria, including
,
, Enterobacteriaceae members, such as
spp., and
spp. have an acquired resistance against colistin. However, other bacteria, including
spp.,
spp. and
spp. are naturally resistant to this antibiotic. In addition, clinicians should be alert to the possibility of colistin resistance among multidrug-resistant bacteria and development through mutation or adaptation mechanisms. Rapidly emerging bacterial resistance has made it harder for us to rely completely on the discovery of new antibiotics; therefore, we need to have logical approaches to use old antibiotics, such as colistin. This review presents current knowledge about the different mechanisms of colistin resistance.
•We have identified significant factors influencing the ride-sourcing usage frequency.•We have used Random Forest technique to select the most important factors.•We have used Bayesian Network method ...to predict the use frequency of ride-sourcing.
This study used a survey technique to investigate factors that motivate the adoption and the usage frequency of ride-sourcing among students in a Malaysia public university. Two of the most broadly used machine learning techniques, Random Forest technique and Bayesian network analysis were applied in this study. Random Forest was employed to establish the relationship between ride-sourcing usage frequency and students' socio-demographic related factors, built environment considerations, and attitudes towards ride-sourcing specific factors. Random Forest identified 10 most important factors influencing university students’ use of ride-sourcing for different travel purposes, including study-related, shopping, and leisure travel. These important predictors were found to be indicators of the target variables (i.e., ride-sourcing usage frequency) in Bayesian network analysis. Bayesian network analysis identified the students' age (0.15), safety perception (0.32), and neighbourhood facilities in a walkable distance (0.21) as the most important predictors of the use of ride-sourcing among students to get to school, shopping, and leisure, respectively.
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•Structural engineering through terminal group has been performed.•Electrostatic potential has been studied qualitatively and quantitatively.•Non-covalent interactions are studied ...using reduced density gradient method.•Bulk properties are analyzed using molecular dynamics simulations.
Chemical structural engineering is a helpful method to design the semi-conductors for organic solar cells (OSCs). The understanding of structural and electronic properties of materials is essential for designing and calibration of materials. By making structural adjustments at the terminal position, new small molecule acceptors can be created. Electronic properties are studied in detail. Electrostatic potential both in qualitative and quantitative way is studied to explore the electron density distribution. The electron density is significantly changed on the change of terminal groups. The excited state behaviour has also undergone a noticeable alteration. The increase in electron-deficient character at the terminal location causes the absorption spectra to shift to the red. The structural changes have an important effect on non-covalent interactions also. Through molecular dynamics (MD) simulations, the bulk behaviour of pure small molecule acceptors and their blend with polymer donor PM6 is examined. Radial distribution function is attained from MD simulations. The alteration in terminal groups has significantly changed the packing behavior of pristine acceptors and their blend with polymer donor.
Abstract
This study was conducted to delineate diversity and species composition of non-diatoms planktonic algae in Hoor- Al- Azime marshes, Iran. The samples were collected from four sites at ...monthly basis from April 2011 to March 2012. A total 88 taxa were identified, out of which (40 taxa, 45.45%) belonging to Cyanophyta followed by Chlorophyta (29 taxa, 32.96%), Euglenophyta (18 taxa, 20.45%) and (1 taxa, 1.14%) of Dinophyta recorded. Comparing species richness (65 taxa, 34.76%) at Shat- Ali (St4) was the highest and the lowest (34 taxa, 18.18%) was observed at Rafi (St2). Species occurrence was associated with temperature where in summer (66 taxa) and (25 taxa) encountered winter. The phytoplankton density ranged from 51.04 ×103 cells/Liter in summer to 2.17 ×103 cells/Liter in winter for Cyanophyta and from 20.58 ×103 cells/Liter in summer to 2.92 ×103 cells/Liter in winter for Chlorophyta. St4 is characterized by the highest density 36.33×103 cells/Liter (43.96 %), while St2 recorded the lowest phytoplankton density 7.33×103 cells/Liter (8.93%). Euglenophyta and Dinophyta did not record a noticeable density during study period. This study document updated knowledge of non-diatom plankton diversity and seasonal oscillation an important wetland ecosystem.
Abstract
Objective
The current study aimed to investigate the temporal trend of in-hospital and intensive care unit (ICU) mortality of coronavirus disease 2019 (COVID-19) patients over 6 months in ...the spring and summer of 2021 in Iran.
Design
We performed an observational retrospective cohort study.
Setting
Qazvin Province- Iran during 6 month from April to September 2021.
Participants
All 14355 patients who were hospitalized with confirmed COVID-19 in hospitals of Qazvin Province.
Intervention
No intervention.
Main outcome measures
The trends of overall in-hospital mortality and ICU mortality were the main outcome of interest. We obtained crude and adjusted in-hospital and ICU mortality rates for each month of admission and over surge and lull periods of the disease.
Results
The overall in-hospital mortality, early mortality and ICU mortality were 8.8%, 3.2% and 67.6%, respectively. The trend for overall mortality was almost plateau ranging from 6.5% in July to 10.7% in April. The lowest ICU mortality was 60.0% observed in April, whereas it reached a peak in August (ICU mortality = 75.7%). Admission on surge days of COVID-19 was associated with an increased risk of overall mortality (Odds ratio = 1.3, 95% confidence interval = 1.1, 1.5). The comparison of surge and lull status showed that the odds of ICU mortality in the surge of COVID-19 was 1.7 higher than in the lull period (P-value < 0.001).
Conclusions
We found that the risk of both overall in-hospital and ICU mortality increased over the surge period and fourth and fifth waves of severe acute respiratory syndrome coronavirus 2 infection in Iran. The lack of hospital resources and particularly ICU capacities to respond to the crisis during the surge period is assumed to be the main culprit.
Evaluating the efficacy of anticancer drugs is an evolving and research-oriented issue. The objective of this study was to reduce the insolubility of chlorambucil (CBL) in water and improve the ...anticancer activity of CBL in vitro and in vivo through the conjugation of CBL with anionic linear-globular dendrimer (second generation, G2). In the current study, the anticancer activity among three groups that include CBL, CBL-G2 dendrimer, and control was measured in vitro and in vivo. In vitro studies showed that G2 anionic linear-globular polyethylene-glycol-based dendrimer, which conjugated to the CBL exterior through an ester linkage, was able to significantly improve the treatment efficacy over clinical CBL alone with respect to proliferation assay, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide; half maximal inhibitory concentration (IC50) was calculated to be 141 µg/mL for CBL alone and 27.7 µg/mL for CBL-G2 dendrimer; P<0.05. In addition, CBL-G2 dendrimer conjugate forestalled the growth of MCF-7 cancerous cells in addition to enhancing the number of apoptotic and necrotic cells as demonstrated by an annexin V-fluorescein isothiocyanate assay. CBL-G2 dendrimer conjugate was able to checkmate antiapoptotic Bcl-2 expression and Bcl-2/Bax ratio in a large scale compared with the control group and CBL alone (P<0.005). In vivo studies showed that tumor treatment by CBL-G2 dendrimer conjugate outstrips the efficacy of treatment compared with CBL alone. The evaluation was based on reduction in tumor volume and tumor growth inhibition of murine 4T1 mammary tumor cells. Tumor volume of 140%±8% was measured in the treatment with CBL-G2 dendrimer, whereas 152%±13.5% was calculated in the treatment with free CBL (P<0.05). However, there were no significant differences in histological assay among the three groups. In conclusion, tumor growth suppression potential of CBL-G2 dendrimer, which was assessed in both in vitro and in vivo experiments, has provided empirical evidence to buttress the fact that this compound could be considered for functional cancer treatment with low side effects.
Exosomes, widely recognized natural nanovesicles, represent one of the recently discovered modes of intercellular communication due to their ability to transmit crucial cellular information that can ...be engineered to have robust delivery and targeting capacity. MiR-142-3p, one of the upregulated microRNAs (miRNAs) in many types of breast cancer, activates the canonical Wnt signaling pathway and transactivates the miR-150 expression, and results in the hyperproliferation of cancer cells in vitro and mammary glands in vivo.
In this study, we exploited the exosomes isolated from bone marrow-derived mesenchymal stem cells (MSCs-Exo) to deliver LNA (locked nucleic acid)-modified anti-miR-142-3p oligonucleotides to suppress the expression level of miR-142-3p and miR-150 in 4T1 and TUBO breast cancer cell lines.
The in vitro results showed that the MSCs-Exo can efficiently deliver anti-miR-142-3p to reduce the miR-142-3p and miR-150 levels and increase the transcription of the regulatory target genes,
and
. We also evaluated in vivo distribution of the MSCs-Exo in tumor-bearing mice. The in vivo result indicated that MSCs-Exo can penetrate the tumor site and are suitable nanovehicles to deliver the inhibitory oligonucleotides into the tumor tissues to downregulate the expression levels of miR-142-3p and miR-150.
We showed that MSCs-derived exosomes could be used as a feasible nanovehicle to deliver drug molecules like LNA-anti-miR-142-3p in both in vitro and in vivo studies.
Fibrosis of subconjunctival tissues is a major cause of bleb failure following glaucoma filtration surgery. The aim of the present investigation was to demonstrate the effect of Rapamycin, a ...clinically relevant macrolide antibiotic with potent immunosuppressive properties, on human Tenon fibroblast proliferation induced by platelet-derived growth factor and basic fibroblast growth factor.
Primary Tenon fibroblast cultures were derived from patients undergoing trabeculectomies or routine cataract extractions. Rapamycin was added in concentrations of 0.1-100 ng/ml with or without 3-30 ng/ml of porcine platelet-derived growth factor or of human recombinant basic fibroblast growth factor. Two days after treatment, the cells were examined and counted. The results were expressed as the percent of cell growth in treated culture relative to its untreated control.
Rapamycin was not cytotoxic at any of the concentrations tested. Inhibition of platelet-derived growth factor-induced Tenon fibroblast proliferation occurred with all doses of Rapamycin, the most marked effect being observed with 30 ng/ml (60% inhibition, p < 0.001). In contrast, optimal inhibition of basic fibroblast growth factor-induced proliferation was only 37% (p < 0.01), achieved with 10 ng/ml of the peptide.
Rapamycin potently inhibits platelet-derived growth factor-induced fibroblast proliferation in vitro without any apparent cytotoxicity. It may eventually prove to be a useful adjunct to glaucoma filtration surgery.
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