Synthesis of Ni2+-functionalized polydopamine magnetic beads for facilitated purification of histidine-tagged proteins.

Facilitated purification of proteins, at a low cost and a short time, is one of the key steps in the industrial production of recombinant proteins. In the current study, polydopamine nanoparticles (PDA-NPs) are considered in the synthesis of magnetic beads for purifying recombinant proteins due to advantages such as biocompatibility/ biodegradability, easy synthesis, as well as the ability to directly chelate metal ions. They were synthesized in Tris buffer (pH: 8:5), then chelated with Fe3+(20 mg) and Ni2+ ions at concentrations of 2, 3, 5, and 7 mg/ml. Prepared nanoparticles were characterized through scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV-vis), dynamic light scattering (DLS), Inductively Coupled Plasma (ICP), and vibrating sample magnetometer (VSM). The size distribution of the particles was reported in the narrow range of 120-140 nm and 200 to 220 nm by the SEM image and DLS analysis, respectively. The chelation of ions on the surface of the nanoparticle was confirmed by the ICP technique with a magnetization of 35.42 emu/g. The highest adsorption rate of Ni2+ ions to polydopamine was obtained at a ratio of 1.4. The SDS-PAGE and western blot analysis confirmed the purification of eGFP and Hsp40 by PDA/Fe3+/Ni2+ at 26 and 40 kDa compared to the commercial nickel column. Moreover, the concentration of purified eGFP by PDA/Fe3+/Ni2+ was reported 138.83 µg/ml by the fluorescent signals, which is almost equal to or more than the protein purified by commercial Ni-NTA column (108.28 µg/ ml). The stability of PDA/Fe3+/Ni2+ has also been evaluated by ICP-OES for 10 days, and the result suggested that PDA magnetic beads were stable. Therefore, it can be concluded that PDA/Fe3+/Ni2+ have the ability to purify recombinant proteins in one less step and shorter time.

SARS-CoV-2 infection and increasing autoimmune disorders among ICU-hospitalized COVID-19 patients.

INTRODUCTION: In acute conditions, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes multi-organ damage due to the induction of inappropriate immune responses, particularly lung tissue fibrosis. To evaluate the consequence of the deterioration of the immune system, autoimmune markers were assessed. METHODS: In a case-control study, 108 patients with coronavirus disease 2019 (COVID-19) were admitted to the intensive care unit (ICU), and 158 outpatients with mild clinical symptoms, with SARS-CoV-2 reverse transcription quantitative polymerase chain reaction (RT-qPCR) positive tests, were included for comparison. The demographic and hematologic variables and presence of the main autoantibodies in sera of 40 eligible ICU-hospitalized COVID-19 patients and 40 COVID-19 outpatients were assessed. Out of 108 COVID-19 ICU-hospitalized patients, 40 were selected as the control group (40/158) who had no underlying diseases before hospitalization, according to their self-declaration and clinical records at the time of admission. RESULTS: The results demonstrated that the main complete blood count indices, such as red blood cells and platelets, decreased dramatically in ICU-hospitalized patients. Furthermore, the autoantibody profiles were positive in 45% and 15% of ICU-admitted patients for antinuclear antibodies and antineutrophilic cytoplasmic autoantibodies, respectively. In ICU patients, anti-PM/Scl 100 or AMA-M2 was 33%. Anti SS-A, anti-SS-B, anti-Ro-52, and anti-Jo-1 in 11.5% for each one were reactive. Other autoantibodies of the ICU group were as follows: CENP (5.6%), Rib-protein (5.6%), and nucleosome (5.6%). However, only two individuals in the control group had positive results for SS-A and SS-B (5%). CONCLUSION: Induction of such particular autoantibodies by the virus can justify the multi-organ involvement and severity of the disease in ICU patients, which may also cause other organ involvement in the long term.

Synthesis and characterization of Gd3+-loaded hyaluronic acid-polydopamine nanoparticles as a dual contrast agent for CT and MRI scans.

Magnetic resonance imaging and computed tomography (CT) suffer from low contrast sensitivity and potential toxicity of contrast agents. To overcome these limitations, we developed and tested a new class of dual contrast agents based on polydopamine nanoparticles (PDA-NPs) that are functionalized and targeted with hyaluronic acid (HA). These nanoparticles (NPs) are chelated with Gd3+ to provide suitable contrast. The targeted NPs were characterized through ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), infrared Fourier transform (FTIR), and dynamic light scattering (DLS). The cytotoxicity was investigated on HEK293 cells using an MTT assay. The contrast property of synthesized Gd3+/PDA/HA was compared with Barium sulfate and Dotarem, as commercial contrast agents (CAs) for CT and MRI, respectively. The results illustrated that synthesized PDA-NPs have a spherical morphology and an average diameter of 72 nm. A distinct absorption peak around 280 nm in the UV-vis spectrum reported the self-polymerization of PDA-NPs. The HA coating on PDA-NPs was revealed through a shift in the FTIR peak of C=O from 1618 cm-1 to 1635 cm-1. The Gd3+ adsorption on PDA/HA-NPs was confirmed using an adsorption isotherm assay. The developed CA showed low in vitro toxicity (up to 158.98 µM), and created a similar contrast in MRI and CT when compared to the commercial agents. The r1 value for PDA/HA/Gd3+ (6.5 (mg/ml)-1 s-1) was more than Dotarem (5.6 (mg/ml)-1 s-1) and the results of the hemolysis test showed that at concentrations of 2, 4, 6, and 10 mg/ml, the hemolysis rate of red blood cells is very low. Additionally, the results demonstrated that PDA/HA/Gd3+ could better target the CD44+-expressing cancer cells than PDA/Gd3+. Thus, it can be concluded that lower doses of developed CA are needed to achieve similar contrast of Dotarem, and the developed CA has no safety concerns in terms of hemolysis. The stability of PDA/HA/Gd3+ has also been evaluated by ICP-OES, zeta potential, and DLS during 3 days, and the results suggested that Gd-HA NPs were stable.

Deep Eutectic Solvents as Phase Change Materials in Solar Thermal Power Plants: Energy and Exergy Analyses.

Nowadays, producing energy from solar thermal power plants based on organic Rankine cycles coupled with phase change material has attracted the attention of researchers. Obviously, in such solar plants, the physical properties of the utilized phase change material (PCM) play important roles in the amounts of generated power and the efficiencies of the plant. Therefore, to choose the best PCM, various factors must be taken into account. In addition, considering the physical properties of the candidate PCM, the issue of environmental sustainability should also be considered when making the selection. Deep eutectic solvents (DESs) are novel green solvents, which, in addition to having various favorable characteristics, are environmentally sustainable. Accordingly, in this work, the feasibility of using seven different deep eutectic solvents as the PCMs of solar thermal power plants with organic Rankine cycles was investigated. By applying exergy and energy analyses, the performances of each were compared to paraffin, which is a conventional PCM. According to the achieved results, most of the investigated "DES cycles" produce more power than the conventional cycle using paraffin as its PCM. Furthermore, lower amounts of the PCM are required when paraffin is replaced by a DES at the same operational conditions.

Energy Conservation in Absorption Refrigeration Cycles Using DES as a New Generation of Green Absorbents.

Deep eutectic solvents (DESs) are emerging green solvents with very unique characteristics. Their contribution to atmospheric pollution is negligible, and they can be "designed" for desired properties. In this study, the feasibility of applying DESs (Reline, Ethaline, or Glyceline) as absorbents in absorption refrigeration cycles was investigated. The sophisticated cubic-plus-association (CPA) equation of state, considering the strong intermolecular interactions of such complex systems, was used to estimate the thermodynamic properties. At a fixed set of base case operating conditions, the coefficients of performance were calculated to be 0.705, 0.713, and 0.716 for Reline/water, Ethaline/water, and Glyceline/water systems, respectively, while the corresponding mass flow rate ratios were 33.73, 11.53, and 16.06, respectively. Furthermore, the optimum operating conditions of each system were estimated. To verify the feasibility, results were compared to literature systems, including LiBr/water and various ionic liquid/water systems. The results indicate that DES/water working fluids have the potential to be used in such cycles. Since DESs have the characteristic to be tuned (designed) to desired properties, including their solvent power and their enthalpies of absorption, much further research needs to be done to propose new DESs with higher energy efficiencies.

Nursing managers attitude toward spirituality and spiritual care in Khorasan Razavi Province hospitals in 2016.

BACKGROUND AND AIM: Spiritual care is an important part of nursing practice that seems to provide comprehensive care to patients. Nursing manager's attention to the spiritual dimension is one of the most important aspects affecting human health. Therefore, the aim of this study was to determine nursing managers' attitude to spirituality and spiritual care in hospitals in Khorasan Razavi Province in 2016. METHODS: In this cross-sectional study, 110 management nurses (8 matrons, 37 supervisors and 65 head nurses) of hospitals in Khorasan Razavi Province (2016) were recruited for the study. Data were collected using a Spirituality & Spiritual Care Rating Scale (SSCRS) questionnaire in two parts, demographic information and questions related to the research objectives. Data were collected and analyzed using SPSS 16 software and doing descriptive (frequency, mean, standard deviation) and inferential statistics (independent-samples t-test, ANOVA) and considering levels of significance (p<0.05). RESULTS: The results showed mean and standard deviation in management nursing attitude to spirituality (4.01±0.35) and spiritual care (4.03±0.78). The result showed significant differences between the attitude to spirituality and spiritual care and gender, age and work experience in nursing management (p<0.05). CONCLUSIONS: Management nursing has high level attitude to spirituality and spiritual care. Therefore, providing the perfect platform to provide this care, and for nurses to implement it in hospitals is recommended.

Quasi-Chemical PC-SAFT: An Extended Perturbed Chain-Statistical Associating Fluid Theory for Lattice-Fluid Mixtures.

In this study, a new modification of the perturbed chain-statistical associating fluid theory (PC-SAFT) has been proposed by incorporating the lattice fluid theory of Guggenheim as an additional term to the original PC-SAFT terms. As the proposed model has one more term than the PC-SAFT, a new mixing rule has been developed especially for the new additional term, while for the conventional terms of the PC-SAFT, the one-fluid mixing rule is used. In order to evaluate the proposed model, the vapor-liquid equilibria were estimated for binary CO2 mixtures with 16 different ionic liquids (ILs) of the 1-alkyl-3-methylimidazolium family with various anions consisting of bis(trifluoromethylsulfonyl) imide, hexafluorophosphate, tetrafluoroborate, and trifluoromethanesulfonate. For a comprehensive comparison, three different modes (different adjustable parameters) of the proposed model were compared with the conventional PC-SAFT. Results indicate that the proposed modification of the PC-SAFT EoS is generally more reliable with respect to the conventional PC-SAFT in all the three proposed modes of vapor-liquid equilibria, giving good agreement with literature data.

An epidemiological study of gastroesophageal reflux disease and related risk factors in urban population of mashhad, iran.

BACKGROUND: Gastroesophageal Reflux Disease (GERD) is a chronic and common disease, which is characterized by heartburn and regurgitation. In the last couple of decades, GERD has received much attention and studies have shown an increase in its prevalence. Although there have been a few studies on the prevalence of GERD in Iran, no study has yet been done in the northeastern part of the country. The aim of our study was to evaluate the prevalence of GERD and its risk factors in a population from Mashhad. OBJECTIVES: To evaluate the epidemiology of GERD based on a population study in Mashhad. PATIENTS AND METHODS: This was a cross sectional descriptive study conducted in 2010. In total, 2500 participants were selected based on cluster sampling. Modified and validated Mayo Clinic questionnaire for GERD was used for data collection. Overall, 1685 questionnaires were retrieved. Fifty-one participants were excluded because of pregnancies, history of abdominal surgery and being less than 18 years old. We analyzed data using the SPSS software version 16. Prevalence of GERD and significant risk factors (P value < 0.05) were determined. RESULTS: In total, 420 participants (25.7%) had GERD symptoms. Risk factors with significant effects consisted of smoking, consumption of non-steroidal anti-inflammatory drugs (NASIDs), overeating, chronic diseases, tea and coffee consumption and GERD in spouse. CONCLUSIONS: The prevalence of GERD among people living in Mashhad was above the average prevalence in other cities of Iran. However, risk factors seemed to be similar to those reported by other studies.

Water cavities of sH clathrate hydrate stabilized by molecular hydrogen: phase equilibrium measurements.

In this experimental phase equilibrium study, we show for the first time that it is possible to stabilize structure sH of hydrogen clathrate hydrate with the help of some selected promoters. It was established that the formation pressures of these systems are significantly higher than that of structure sII of hydrogen clathrate hydrate when tetrahydrofuran (THF) is used as a promoter. Although no experimental evidence is available yet, it is estimated that the hydrogen storage capacity of structure sH can be as high as 1.4 wt % of H2, which is about 40% higher compared to the hydrogen storage capacity in structure sII.