Low Molecular Weight Substances Research Articles

Influencia de la enfermedad pulmonar obstructiva crónica en los componentes orgánicos volátiles en pacientes con cáncer de pulmón no microcítico

IntroductionThe etiology of lung cancer is multifactorial. Exposure to tobacco smoke and the role played by the carcinogenic compounds that it contains would explain the common association between lung cancer and chronic obstructive pulmonary disease (COPD), a disease which is very much linked to tobacco use. In both diseases, sustained inflammation is caused by increased oxidative stress (for example, lipid peroxidation). This generates low molecular weight substances called volatile organic compounds (VOC) that are excreted during breathing. VOC metabolomics provides an indirect measure of oxidative stress. ObjectiveThe aim of this study was to establish the relative influence of COPD on the VOC profile in patients with non-small cell lung cancer (NSCLC), by first studying the possible variation of VOC associated with lung cancer histology. Patients and methodsExhaled air was tested in 107 NSCLC patients, who were divided into 2groups: NSCLC with COPD and non-COPD with NSCLC. The exhaled air sample was obtained with the BIOVOC® sampler, and transferred to desorption tubes for later analysis by thermal desorption-gas chromatography-mass spectrometry. The VOC analysis showed lineal aldehydes and carboxylic acids. Results and conclusionsNo statistically significant differences were found in VOC associated with histology. NSCLC and COPD patients present a 1.7-fold (1.1-2.7) probability of detection of propionic acid (95% CI: 1.22- 6.2) than patients without COPD or NSCLC (P = 0.013).

Spatiotemporal variability, size and photoreactivity of chromophoric dissolved organic matter in the Bohai Sea and the northern Yellow Sea

The distribution, composition, and photoreactivity of chromophoric and fluorescent dissolved organic matter (CDOM and FDOM) in the Bohai Sea (BS) and the northern Yellow Sea (NYS) were investigated during three cruises (summer 2017, winter 2017, and spring 2018) by combining size fractionation through a series of micro- and ultra-filtrations and irradiation experiments. A total of 484 excitation-emission matrix spectra were modeled by parallel factor analysis to yield four humic-like (C1–3 and C5) and three protein-like (C4 and C6–7) fluorescent components. CDOM in the BS and the NYS was primarily affected by terrestrial inputs. Microbial degradation processes and autochthonous production were considered to be important factors driving the dynamics of fluorescence components. A total of 73 triple CDOM absorption and fluorescence spectra (n = 219) from the study regions were measured on 0.2, 0.45, and 0.7 μm filters in winter; water samples were also collected from the Yellow River Estuary (YRE) to the NYS, which was further size fractionated through ultrafiltration membranes (10 kDa and 1 kDa) to investigate variability between spectra of different filter pore sizes. The significant mean difference of absorption coefficient and fluorescence spectra, and no consistent trend between spectral slope (S275–295, S350–400), slope ratio (SR) from these filtrates suggested that the choice of different filter pore sizes considerably influenced the CDOM optical assessment. Higher values of CDOM and FDOM in the particulate phases (0.2–0.7 μm) fraction were more distributed in the NYS where terrestrial inputs were less and DOM dynamics were more linked with phytoplankton production. As pore size decreased, the percentage of humic-like fluorescence increased suggesting that humic-like components of CDOM were more dominated by low-molecular-weight (LMW) materials compared with the protein-like components. Consistent with its higher terrestrial CDOM content, photodegradation resulted in losses of CDOM and FDOM and increasing of the spectral slope ratios (SR). These finding suggested that CDOM molecules were photochemically degraded to LMW substances. Our results indicated that the proportion of the LMW CDOM decreased from estuary to open sea, which likely resulted from high-molecular-weight (HMW) organic material produced during phytoplankton production in off-shore regions, and LMW substances produced during CDOM photochemical processes in coastal waters.

POLYETHYLENE TEREPHTHALATE WASTE RECYCLING TECHNOLOGY TO PRODUCE TEREPHTHALIC ACID AMIDE

The purpose of this study is to conduct and study the process of chemical recycling of solid household waste of polyethylene terephthalate (PET) with a mixture of amino alcohols (monoethanolamine and triethanolamine) under relatively mild conditions and without the use of catalysts. It was revealed that during the reaction of PET with a mixture of amino alcohols of a low molecular weight white product is formed, containing in its structure an aromatic core, two amide and two hydroxyl groups - N, N'-bis (2-hydroxyethyl) terephthalamide. The most effective purification and isolation of the target low molecular weight compound from the reaction mixtures is achieved by recrystallization from water. The structure of the obtained compound was studied using IR Fourier spectrometry, gas chromatography-mass spectrometry and differential scanning calorimetry, as well as some physicochemical properties of the obtained compound (solubility, melting point). A technological scheme for obtaining this low molecular weight substance in relatively large volumes by a periodic method with the regeneration of the initial amino alcohols for their reuse is proposed. The process is carried out in a heated batch reactor, which receives crushed PET waste, as well as a mixture of amino alcohols. The reaction mass is maintained at a temperature of 160 °C and periodic stirring for 3-4 h. After completion of the reaction and cooling the mixture is fed into the apparatus-crystallizer for further selection of the target product by crystallization from water. In addition, on the basis of the available experimental data and theoretical assumptions, the possibility in principle of using the obtained low-molecular compound as a monomer in the polycondensation reaction to obtain polyamidoesters is considered, similar to the principles of obtaining polyethylene terephthalate from diglycolterephthalate. It was shown that the depolymerization product enters into a polycondensation reaction with the formation of an oligomeric product - a viscous, resinous mass having a color from yellow to caramel.

Применение наночастиц золота для высокочувствительного поляризационного флуоресцентного аптамерного анализа охратоксина А

Предложено применение наночастиц золота (НЧЗ) в качестве носителей для снижения предела обнаружения поляризационного флуоресцентного (ПФ) аптамерного анализа. ПФ-анализ основывается на различиях флуорофора, конъюгированного с аналитом и облучаемого плоскополяризованным светом, по степени деполяризации излучаемого света до и после связывания аналита с рецептором. Применение аптамеров в качестве рецепторов в таком анализе ограничено из-за их небольшой молекулярной массы и соответственно недостаточного влияния на поляризацию. Данное ограничение может быть устранено посредством включения аптамеров в крупные межмолекулярные комплексы. Показаны преимущества НЧЗ как унифицированного, стабильного и легкомодифицируемого носителя для аптамеров. ПФ-аптамерный анализ реализован с применением НЧЗ, имеющих средний диаметр 8.7 нм, и охратоксина А (ОТА) в качестве целевого аналита. Анализ апробирован для тестирования проб белого вина. Достигнутый предел обнаружения ОТА — 2.3 мкг/кг, что в 25 раз ниже, чем при использовании нативного аптамера. Продолжительность анализа — 15 мин. Предлагаемый подход может применяться для аптамерного анализа различных низкомолекулярных соединений.

Preparation, characterization, and application of magnetic activated carbon for treatment of biologically treated papermaking wastewater

In view of the urgent need for tertiary treatment of papermaking wastewater and the difficulty in separating powdered activated carbon (PAC) from water, the magnetic activated carbon (33%-MPAC, 50%-MPAC and 67%-MPAC) were prepared by chemical coprecipitation method for adsorption of biologically treated papermaking wastewater (BTPW). A series of characterization of MPAC and PAC were carried out and show that the content of iron oxides is negatively related to the proportion of micropores in MPAC. The loaded iron oxides is mainly the mixture of magnetite and maghemite, and the maximum saturation magnetization of MPAC can reach 29.68 emu/g. Batch mode experiments were performed, and found that the adsorption effect of MPAC is slightly worse than that of PAC, the adsorption capacity of COD in MPAC can reach about 65 mg/g, and pH = 2 and 10 °C are more favorable for adsorption. The adsorption isotherms and kinetics were well fitted by the Freundlich model and pseudo-second-order kinetic model, respectively. The selective adsorption was studied by using the excitation emission matrix (EEM) fluorescence spectrum and high-performance size exclusion chromatography (HPSEC). It is concluded that all adsorbents are preferred to adsorb humic acid-like substances (HA). And all adsorbents are preferred to adsorb low apparent molecular weight substances (LAMW, AMW < 1500 Da), with the increase of iron oxides content, the phenomenon of MPAC preferentially adsorbed LAMW became less obvious.

Comparison of remineralizing effect of organic and inorganic fluoride by evaluation of microhardness and quantitative analysis of calcium and phosphorus ratio on enamel surface: an in-vitrostudy

Background Enamel is a highly mineralized tissue of the body which is composed of 96% inorganic salts and 4% organic matter. Enamel is permeable to water and ions, particularly cations and low molecular weight substances. The enamel continues to mature even after eruption with mineral replacing protein. Recently, the interest on the development of calcium phosphate-based remineralization technology has been increased that led to the development of various remineralizing agents like Fluoride, CPP-ACP (Tooth Mouse plus), Bioglass (Novamin), Ozone, Xylitol, Sensistat etc. Aim Aim of the present in vitro study was to evaluate and compare the remineralizing effect of Organic fluoride (AmF) and inorganic fluoride (NaF) by evaluating Vickers microhardness and quantitative analysis of Calcium and Phosphorus ratio on enamel surface using Scanning Electron Microscope-Energy Dispersive X-ray analysis. Materials and methods Sixteen maxillary central incisors were decoronated at the cementoenamel junction and mounted in cylindrical moulds filled with self-cure acrylic resin. Artificial demineralized lesions were created on the enamel surface by suspending them in 0.1 M Citric acid buffer at pH of 3.2 for 72 hrs. The samples were then randomly divided into two groups and labelled, Group A – remineralized with NaF for 3 minutes twice daily for one week and Group B - remineralized with AmF for 3 minutes twice daily for one week. Microhardness and SEM-EDX analysis were done before demineralization, after demineralization and after remineralization. Results Data were analyzed by comparing the mean values between the groups using independent sample t-test. The intra-group analysis was done using repeated-measures ANOVA with posthoc Bonferroni test, and a p-value of <0.05 was considered statistically significant. Conclusion OrganicFluoride resulted in better remineralization than inorganic Fluoride. After remineralization for one week, enamel samples treated with AmF demonstrated a statistically significant increase in mean microhardness and Ca:P ratio when compared to enamel samples treated with NaF.

Assessment of endogenous intoxication values by oral fluid composition

To study changes in the parameters of endogenous intoxication using the level of substances of low and medium molecular weight in the oral fluid in patients with catarrhal stomatitis, which got developed after the acute drug poisoning. To determine the degree of intoxication, we studied the concentrations of low and medium molecular weight substances (SLMMW) in the oral fluid of patients. We studied the saliva of 20 patients (13 men and 7 women, average age 39 years). The control was done against the oral fluid of 10 healthy individuals. The studies were conducted in a control group consisting of 10 healthy individuals with intact oral mucosa and two groups of patients (20 patients in total) with drug poisoning. The first of these two groups of patients included 8 individuals without pathological changes in the oral mucosa, while the second group consisted of 12 patients diagnosed with catarrhal stomatitis that developed after acute drug poisoning. It became known that endogenous intoxication develops in the oral fluid of patients with acute drug poisoning, which is manifested by a statistically significant increase in the content of SLMMW in comparison with practically healthy individuals (15.3%). And the total level of SLMMW in the oral fluid of patients with acute drug stomatitis and catarrhal stomatitis has increased by 42.3% relative to the data of practically healthy individuals. Studies have shown the need for monitoring the oral cavity in patients with acute drug poisoning, with the aim of timely detection of pathologies of the oral mucosa in them and the appointment of complex treatment.

Testing a Novel Heat-Shock Protein Inducer in the Cellular Model of Traumatic Brain Injury Response

Traumatic brain injury (TBI) induces multiple pathological processes affecting various brain cells. the accumulation of toxic factors in interstitial and cerebrospinal fluid may be a consequence of TBI and massive cell death. The accumulation process, causing so-called “secondary damage,” is not transient and often lasts within days and weeks. We believe that Hsp70 protein can play an important role in reducing the severity of posttraumatic pathological complications. Chaperone Hsp70 is known for its cytoprotective activity, and, therefore, an approach involving its increase in in cells exposed to proapoptotic and proinflammatory factors may turn out to be extremely promising. In support of this idea, we studied the effect of the low molecular weight substance KD-29, which is able to induce the synthesis of Hsp70 in the cellular model of the posttraumatic process. We used rat C6 glioma cells to study the cytotoxic effect of rat cerebrospinal fluid obtained after TBI. We found that the drug KD-29 significantly inhibited the apoptosis process and increased the proliferative activity of C6 cells under conditions of modeling posttraumatic processes.

Study of the specifics of the formation of immunoglobulin G and immunoglobulin M antibodies to low molecular weight substances (synthetic cannabinoids and antidepressants) in laboratory mice

Background: To date, there is little evidence in the literature about the effects of synthetic cannabinoids “spice” and antidepressants on the mammalian immune system. Aims and Objectives: The study of the formation of immunoglobulin (Ig)G and IgM class antibodies to synthetic cannabinoids “spice” and antidepressants for a comparative assessment of the role of the class of antibodies in the detection of dependence on psychotropic drugs. Materials and Methods: Conjugates were obtained with four antidepressants: Faverin, carbamazepine, sertraline, and fluoxetine and two synthetic cannabinoids of the “spice” type – AB-FUBINACA and ADB-CHMINACA in conjunction with the carrier protein-bovine serum albumin. The serological activity of synthesized conjugates based on the protein matrix was determined. Results: Data were obtained on the determination of antibodies to the studied synthetic cannabinoids and antidepressants by enzyme-linked immunosorbent assay, and the immunoreactivity of mouse antibodies against heterologous haptens was established. Conclusion: The article examines in detail the issues related to the comparative analysis of the formation of IgG and IgM antibodies to synthetic cannabinoids and antidepressants in mice in the experiment. It has been established that IgM antibodies play a significant role in the diagnosis of psychotropic substances.

ПРИМЕНЕНИЕ АЛЬФА -ФЕТОПРОТЕИНА В ИММУНОФАРМАКОЛОГИИ – ИСТОРИЯ ВОПРОСА

The immunopharmacological potential of alpha-fetoprotein (AFP) is closely related to its ability to modulate the activity of cells of the immune system. Due to the immunomodulating properties, as well as the transport function - the transfer of low molecular weight substances, AFP is used in the treatment of a number of pathological conditions. The first attempts to use the therapeutic potential of AFP are associated with the use of extracts of embryonic tissues, with the development of technology, purified AFP from abortive material was used as a drug, and in some cases, recombinant forms of AFP were used. These drugs are intended primarily for the treatment of autoimmune as well as cancer. The review presents data on known variants of AFP dosage forms. In general, the study of the mechanisms of action of AFP at the level of the immune system is currently an urgent issue.

Analysis of Low Molecular Weight Substances and Related Processes Influencing Cellular Cholesterol Efflux.

Cholesterol efflux is the key process protecting the vascular system from the development of atherosclerotic lesions. Various extracellular and intracellular events affect the ability of the cell to efflux excess cholesterol. To explore the possible pathways and processes that promote or inhibit cholesterol efflux, we applied a combined cheminformatic and bioinformatic approach. We performed a comprehensive analysis of published data on the various substances influencing cholesterol efflux and found 153 low molecular weight substances that are included in the Chemical Entities of Biological Interest (ChEBI) database. Pathway enrichment was performed for substances identified within the Reactome database, and 45 substances were selected in 93 significant pathways. The most common pathways included the energy-dependent processes related to active cholesterol transport from the cell, lipoprotein metabolism and lipid transport, and signaling pathways. The activators and inhibitors of cholesterol efflux were non-uniformly distributed among the different pathways: the substances influencing ‘biological oxidations’ activate cholesterol efflux and the substances influencing ‘Signaling by GPCR and PTK6’ inhibit efflux. This analysis may be used in the search and design of efflux effectors for therapies targeting structural and functional high-density lipoprotein deficiency.

Removal of THM Precursors by Adsorption, Coagulation and UV Irradation

The general characteristics of humic substances (HS) and their negative effect on water quality and its treatment are described. The paper presents the results from the removal of humic substances from the Hriňová (Slovakia) water reservoir using 1) granular activated carbon (GAC) from two producers (Chemviron, Cabot) at three different pH levels, 2) by coagulation with two coagulants (aluminum sulfate and ferric sulfate), and 3) by an advanced oxidation process using UV radiation with the addition of the oxidizing agent hydrogen peroxide. The effectiveness of the removal of humic substances (expressed by the TOC parameter) from water with adsorption by GAC, depending on the contact time with the water, ranged from 14 % for one hour to 50% for eight hours of contact time. The calculated GAC adsorption capacity of the humic substances ranged from 0.05 mg/g for one hour to 0.19 mg/g for eight hours of contact time. The pH of the water had no significant effect on the level of efficiency. A high level of efficiency (50%) and the lowest value of TOC are obtained at a pH of 6.5. The humic substances remain in the water though the optimal dose of the coagulant was used. The ferric sulfate coagulant is more suitable for removing of humic substances from water as aluminum sulfate. A dose of 16 mg/L of 1% solution Fe2(SO4)3, which is the equivalent of 4.47 mg/L Fe3+, is sufficient for the reduction of humic substances below 1 mg/L. The effectiveness of the removal of humic substances with coagulation using iron sulfate was 83% for a parameter of HS and 50% for TOC or CODMn. The iron sulfate has the influence on a reduction in pH of water, therefore pH of water should be adjusted after coagulation. A laboratory study of removal of humic acids from surface water by UV radiation and addition of hydrogen peroxide in order to increase the oxidation of organics are presented. The results showed that UV radiation and addition of H2O2 during the first few minutes of irradiation increases the concentration of the humic substances, CODMn and TOC in water. After 3 minutes of exposure to UV radiation, these values were reduced to baseline, and in the next irradiation phase the values of the monitored parameters decreased. The highly reactive OH radicals with a high oxidation potential oxidize humic substances to various intermediates (a lower molecular weight substances). After 20 minutes of irradiation, a decrease in the parameters of approx. 39% for TOC, 62% for CODMn and 37% for humic substances was observed.

THE SEVERITY OF ENDOGENOUS INTOXICATION AND OXIDATIVE STRESS IN THE BLOOD OF WORKERS IN CONTACT WITH GLYCINE DERIVATIVES

Introduction. Currently, the search for markers of the health status of workers in agro-industrial complexes in contact with pesticides continues. The aim of this study was the assessment of the effect of glyphosate isopropylamine salt on the health of workers in agroindustrial complexes of the Ryazan region according to the severity of endogenous intoxication and oxidative stress in the body. Materials and Methods. Plasma and erythrocytes of peripheral blood of workers were the clinical material for the study. Blood was taken in 87 workers contacted with glyphosate-containing pesticides. As a control group, 20 clinically healthy individuals of the same age category who did not have contact with the pesticides were selected to be studied. The severity of endogenous intoxication was determined by the level of substances of low and medium molecular weight in the plasma and red blood cells. The severity of oxidative stress was determined by the content of the products of oxidative modification of proteins by the method of R.L. Levine modified by E.E. Dubinina. Results. Statistically significant changes in the severity of endogenous intoxication in the blood plasma and erythrocytes of the study groups and the control group of individuals among machine operators and workers who come into contact with pesticides to a lesser extent were obtained. A statistically significant increase in the level of carbonyl derivatives compared with the control among machine operators who have greater contact with glyphosate-containing pesticides according to the time sheets has been revealed. The level of secondary carbonyl derivatives in machine operators was higher than that of warehouse workers and was statistically significant. Conclusion. A statistically significant increase in the level of secondary carbonyl derivatives among machine operators as compared with other workers is a late marker of oxidative stress, which indicates to a depletion of the reserve forces of the body. This may be due to longer contact with pesticides based on glyphosate machine operators as compared to other workers in the agro-industrial complexes.

Forced Oscillation Technique and Small Airway Involvement in Chronic Hypersensitivity Pneumonitis

ObjectiveHypersensitivity pneumonitis (HP) is an interstitial lung disease caused by the inhalation of specific organic antigens or low-molecular weight substances in genetically susceptible individuals. Although small airway involvement is prominent in patients with chronic HP, conventional pulmonary function tests (PFTs) are relatively insensitive to identify it. Thus, the authors aimed to evaluate resistance (R5) and reactance (X5) values at 5Hz on inspiration, expiration, and whole breath, as well as small airway resistance (R5•19) values using a forced oscillation technique (FOT) in patients with chronic HP, and their responses after bronchodilator. In addition, R5 and X5 values according to the presence or absence of mosaic attenuation on computed tomography (CT) were compared. MethodsPFTs with plethysmography, diffusing capacity of the lungs for carbon monoxide (DLCO) and FOT measurements were performed pre-bronchodilator and post-bronchodilator. High-resolution CT was performed at the same visit, and classified according to the presence or absence of mosaic attenuation. R5 and X5 values were then compared according to the presence or absence of mosaic attenuation on CT. ResultsTwenty-eight patients with chronic HP (57.1% female; mean age, 56±11.5 years; mean forced vital capacity 57±17% predicted) were evaluated. All patients had low X5 values, reflecting lower lung compliance, and only three (8%) demonstrated elevated R5 (whole-breath) values. No patients exhibited bronchodilator response in R5, X5 and R5•19 values. In patients who exhibited greater extension of mosaic attenuation (n=11), R5 and X5 values could not discriminate those with a greater presence of these areas on CT. ConclusionsThe results suggest that FOT does not help to additionally characterise concomitant small airway involvement in patients with chronic fibrotic HP who demonstrate restrictive ventilatory pattern in conventional PFTs. Nevertheless, FOT appeared to better characterise decreased lung compliance due to fibrosis through X5. Bronchodilator therapy did not appear to induce an acute response in chronic HP patients with restrictive disease. The precise role of FOT in subacute HP and obstructive chronic HP, therefore, must be evaluated.

Endogenous release of metals with dissolved organic carbon from biochar: Effects of pyrolysis temperature, particle size, and solution chemistry

Metals are released from biochar (BC) in either the free or dissolved organic carbon (DOC)-combined form. The complexation of metals with DOC influences their toxicity and bioavailability in the environment. The endogenous release of metal species with heterogeneous DOC from BC is very complex; this process has been neglected and remains unaddressed in the literature to date. In this study, the yield and chemical properties of labile DOC from BC were characterized, and the release of endogenous metal/metalloid elements (K, Mg, Mn, Fe, Al, Cu, and Si) and their species from BC with various pyrolysis temperatures and particle sizes were systematically investigated under various solution chemistries. The results showed that pyrolysis temperature of BC significantly influenced the yield and composition of DOC and DOC-metal/metalloid complexes, while particle size had lower impact. The yield of BC-derived DOC significantly decreased and the components gradually changed from low-molecular weight and low-aromaticity hydrophilic humic acid-like substances to complex high-molecular weight and high-aromaticity hydrophobic substances as pyrolysis temperature increased from 200 to 700 °C. The release of total dissolved metals decreased with increasing pyrolysis temperature, while the highest total dissolved Si was released from BC with the moderate pyrolysis temperature (500 °C). The metal elements were mainly released in the DOC-combined form, while the released Si was mainly in the free form in the neutral water environment. The release of DOC increased while that of dissolved metals decreased with increasing solution pH. The release of total dissolved metals/metalloids increased but the ratio of the DOC-combined metals/metalloids decreased with increasing solution ionic strength. These results provide new insight into the understanding of endogenous metal/metalloid release from BC in the natural environment.

A Clinical Significance of Intermittent Infusion Hemodiafiltration Using Backfiltration of Ultrapure Dialysis Fluid Compared to Hemodialysis: A Multicenter Randomized Controlled Crossover Trial

Background: Intermittent infusion hemodiafiltration ­(I-HDF) using repeated infusion of ultrapure dialysis fluid through a dialysis membrane or sterile nonpyrogenic substitution fluid was developed to prevent a rapid decrease in blood pressure by increasing the patient’s circulating blood volume, to enhance the plasma refilling rate by improving peripheral circulation, and to enhance solute transfer from the extravascular space to the intravascular space by enhancing the plasma refilling rate. Furthermore, the effect of fouling caused by attachment of proteins to the membrane as a result of ultrafiltration can be reduced by backflushing of the membrane with the purified dialysate in I-HDF. Although there have been several clinical trials of I-HDF, there have been no comparisons of the clinical significance of and indications for ­I-HDF with those of conventional hemodialysis (HD). Objective: The aim of this multicenter randomized controlled crossover trial was to compare the clinical significance of ­I-HDF with that of HD in Japan. Method: Patients were randomized to receive HD, I-HDF, and HD (group A) or I-HDF, HD, and I-HDF (group B) in that order for 14 weeks each. The sample size of 70 was determined based on the operability and patient availability. Treatment outcomes were evaluated 5 and 14 weeks after the start of each treatment period. The patients received 4-h treatment sessions with no changes in session duration or anticoagulant therapy during the study. I-HDF was performed using a GC-110N dialysis machine. Two hundred milliliters of ultrapure dialysis fluid were infused at a rate of 150 mL/min by backfiltration every 30 min during treatment. The first and last infusions were performed 30 min after the start and 30 min before the end of treatment, respectively. The total estimated infusion volume per session was 1.4 L (i.e., 200 mL × 7 infusions). I-HDF is a type of online HDF with a small fluid replacement volume. An ABH-P polysulfone membrane hemodiafilter was used for ­I-HDF and a class 1 or 2 hemodialyzer with a polysulfone membrane not coated with vitamin E and approved by the Japanese reimbursement system was used for HD. The primary outcomes were the Short Form-36 version 2 summary scores for quality of life and the visual analog scale scores for clinical symptoms. Secondary outcomes were vital signs, number of interventions, and pre-treatment blood test results. These variables were evaluated 1 week before at the start of the study, and at 5 and 14 weeks after the start of each treatment period. The removal characteristics of the various solutes were evaluated when possible on the first day of each treatment period. All patients provided written informed consent to participate. Results: Thirty-two patients in group A and 32 patients in group B completed the trial. There were no differences in the primary or secondary outcomes between I-HDF and HD. Serum α₁-microglobulin (MG) levels at 14 weeks were significantly lower for I-HDF than for HD. During treatment, the removal rates for urea and creatinine, which are low molecular weight substances, were significantly lower during I-HDF than during HD. In contrast, the β₂-MG and α₁-MG removal rates were significantly higher during I-HDF than during HD. Furthermore, there was significantly less albumin leak during I-HDF than during HD. The solute removal results reflect the difference in pore size between the hemodiafilter used for I-HDF and the hemodialyzer used for HD and the difference in convective transport attributable to filtration between the 2 methods. Conclusions: These findings show that the removal rates of low molecular weight substances are significantly lower and those of medium to high molecular weight substances are significantly higher with I-HDF than with HD. They also indicate that there is significantly less albumin leak during I-HDF than during HD, meaning that I-HDF may be a particularly suitable dialysis modality for patients with malnutrition and the elderly in Japan.

Synthesys and properties of allyl ethers of phenolphthalein-containing novolacs

The paper presents the results of investigations on the production of allyl ethers of phenolphthalein-containing novolacs, curable without release of low molecular weight substances, and cross-linked copolymers based on them.

Fenton cleaning strategy for ceramic membrane fouling in wastewater treatment

Membrane fouling is an obstacle impeding the wide applications of ceramic membranes and organics are responsible for most of the membrane fouling issues in wastewater treatment. In this study, Fenton cleaning strategy was firstly proposed to clean ceramic membrane fouling in wastewater treatment. Fe2+ efficiently catalyzed fouling cleaning with H2O2 (1.5%) to recover the filterability of ceramic membrane. The maximum ∆TMP recovery (over 99%) was achieved at an optimal Fe2+ dosage of 124 mg/L after 6 hr of immersion cleaning. The total residual membrane fouling resistance decreased gradually from this optimum value as the Fe2+ dosage increased above 124 mg/L. The residual hydraulically reversible fouling resistance accounted for most of the membrane fouling and was basically removed (≤3.0 × 109 m−1) when Fe2+ dosages higher than 124 mg/L were used. The foulants responsible for the formation of a residual hydraulically reversible fouling layer (DOC (dissolved organic carbon), proteins, polysaccharides, EEM (fluorescence excitation-emission matrix spectra), SS (suspended solids), and VSS (volatile suspended solids)) were gradually removed as the Fe2+ dosage increased. These residual organic foulants were degraded from biopolymers (10–200 kDa) to low molecular weight substances (0.1–1 kDa), and the particle size of these residual foulants decreased significantly as a result. The strong oxidation power of hydrogen peroxide/hydroxy radicals towards organic foulants was enhanced by Fe2+. Fe2+ played a significant role in the removal of hydraulically reversible fouling and irreversible fouling from the ceramic membrane. However, Fe2+ (≥124 mg/L) increased the likelihood of forming secondary iron-organics aggregates.

OBTAINING SOME THERMOD AINING SOME THERMODYNAMIC PARAMETERS CONTAINING ME AINING METACRYLATE AND ALL TE AND ALLYL GROUPS CON YL GROUPS CONTAINING IN COMPOSITION

The article discusses the preparation of some thermodynamic parameters characterizing the final product of complex radical polymerization of amino alkyl acrylate derivatives containing both methacrylate and alkyl groups of low molecular weight compounds with electron acceptors - polymerization initiators at temperatures that exclude thermal decomposition of the initiators themselves. The equilibrium constant of the complication reaction and the molar extinction coefficient of the complex were determined by graphically solving the Bеneshe-Hildebrand equation, the heats of complex formation, entropy, Gibbs energy were found, and the elemental composition of low molecular weight and high molecular weight substances was determined. As can be seen from the studies, the molar extinction coefficient of the complex practically does not depend on temperature, and the equilibrium constant of the complexation reaction even in a narrow temperature range (283–293 K) increases with increasing temperature. The structure and composition of the synthesized monomeric and polymer salt were also considered in the work, and confirmed by IR-spectroscopy and analysis of elemental composition, the obtained spectroscopic data showed that the unit of the formed polymer corresponds in composition and structure to the monomeric quaternary salt, and the allyl bond in the polymers is preserved. It can be seen from the studies that, with an increase in the concentration of both the monomer and the initiator, the reaction rate naturally increases.

Hydrophobicity Test of Silicone Rubber Based on Thermogravimetric Analysis

To study the hydrophobicity and the transfer of hydrophobicity of silicone rubber, experiments were conducted under three conditions (low-temperature ashing, room-temperature ashing, and low-temperature salting) on new silicone rubber products. Then the surface hydrophobicity of the material after cleaning the contaminants was measured using the classification of water spray, and the change laws of low molecular-weight substances in the core layer and the surface of silicone rubber samples were studied using the thermogravimetric analysis. The results showed that the low molecular-weight substances, namely the hydrophobic substances, were a typical type of siloxane. After pollutants accumulated on the surface of the silicone rubber, the surface hydrophobicity of the material declined continuously, and the contents of hydrophobic substances in the surface and the core layers reduced with fluctuations at a rate being directly proportional to the ambient temperature. The content and the decrease rate of hydrophobic substances in the surface were slightly higher than those in the core layer. The ashes in the contaminants propelled the transfer of the hydrophobic substances while salts inhibited the transfer. However, the presence of salts accelerated the hydrolysis of silicone rubber molecules in the material surface. The experimental results provide reference for the daily maintenance of composite insulators of electric power enterprises.