Multistage Treatment Research Articles

ASSESMENT OF THE POSSIBILITY THE CALCULATED DOSES OF COAGULANT REDUCING T FOR THE TREATMENT OF LANDFILL LEACHATE

The article analyses the prerequisites for the formation of environmentally hazardous leachate generated during the life cycle of solid waste landfills, namely, during the decomposition of their organic component, in particular, including the stage of aceto- and methanogenesis. The article emphasises the multicomponent nature of the generated wastewater and the pollution's high level by such indicators as biological oxygen demand, chemical oxygen demand, suspended solids, and colour. This necessitates the use of multi-stage treatment technologies, including mechanical and biological treatment. The main goal of the article was to find out which ways and approaches able to improve of treatment efficiency, in particular using the mechanical treatment stage (pre-treatment). The colour and suspended solids content were chosen as control indicators, and the assessment of the dynamics of changes in these indicators and the level of their sensitivity to the coagulant's work's (use of aluminium sulphate as a coagulant) makes it possible to make conclusions about the effectiveness of the proposed method. In particular, the paper had been proposed the use of an activated solution of aluminium sulphate coagulant, the properties of which change and the efficiency increases under the action of magnetic-electric activation. This approach, as we are expecting is to intensify the leachate treatment process and reduce reagent consumption by 25-30% without the quality of treatment reducing, will allow to reduce the residual amount of aluminium in treated wastewater, to reduce the amount of sediment formed during the treatment of drainage wastewater, and to minimize the negative impact on the environment during the discharge of treated wastewater into surface sources. The selected optimal dose of the coagulant allows maintaining the required technological mode of operation of the treatment facilities in case of changes in the quality of wastewater entering the facilities. The use of aluminium sulphate as a coagulant was proposed, and the studies were carried out in in the following dose range 100-350 mg/dm3. Keywords: dose, coagulant, leachate, efficiency, assessment, suspended solids, colour, sludge, activation

Combination of separation and degradation methods after PFAS soil washing

The current study evaluated a three-stage treatment to remediate PFAS-contaminated soil. The treatment consisted of soil washing, foam fractionation (FF), and electrochemical oxidation (EO). The possibility of replacing the third stage, i.e., EO, with an adsorption process was also assessed. The contamination in the studied soils was dominated by perfluorooctane sulfonate (PFOS), with a concentration of 760 and 19 μg kg−1 in soil I and in soil II, accounting for 97 % and 70 % of all detected per-and polyfluoroalkyl substances (PFAS). Before applying a pilot treatment of soil, soil washing was performed on a laboratory scale, to evaluate the effect of soil particle size, initial pH and a liquid-to-soil ratio (L/S) on the leachability of PFAS. A pilot washing system generated soil leachate that was subsequently treated using FF and EO (or adsorption) and then reused for soil washing. The results indicated that the leaching of PFAS occurred easier in 0.063–1 mm particles than in the soil particles having a size below 0.063 mm. Both alkaline conditions and a continual replacement of the leaching solution increased the leachability of PFAS. The analysis using one-way ANOVA showed no statistical difference in means of PFOS washed out in laboratory and pilot scales. This allowed estimating twenty washing cycles using 120 L water to reach 95 % PFOS removal in 60 kg soil. The aeration process removed 95–99 % PFOS in every washing cycle. The EO and adsorption processes achieved similar results removing up to 97 % PFOS in concentrated soil leachate. The current study demonstrated a multi-stage treatment as an effective and cost-efficient method to permanently clean up PFAS-contaminated soil.

Clinical case of successful treatment of a patient with anaplastic thyroid cancer in combination with ischemic heart disease and critical multivessel coronary artery disease

The article presents a clinical case of a patient with locally advanced anaplastic thyroid cancer and concomitant cardiovascular pathology. Anaplastic thyroid cancer is a very rare and highly aggressive disease requiring long-term multistage treatment, often using cardiotoxic drugs. Combination of this pathology with ischemic heart disease affecting coronary arteries is a complex clinical problem requiring timely evaluation of cardiac risk at every stage. Treatment of this patient cohort is possible only by a multidisciplinary team of specialists.

Multi-Stage Treatment for Spetzler-Martin Grades III, IV, and V Arteriovenous Malformations: Preoperative Embolization and Microsurgical Resection in a Consecutive Series of 250 Patients.

The treatment of high-grade brain AVMs is challenging and has no guidelines available to date. This study was aimed at reporting the experience of two centers in treating these AVMs through a multi-stage approach consisting of preoperative embolization and microsurgical resection. A retrospective review was performed for 250 consecutive patients with a diagnosis of high-grade brain AVM (Spetzler-Martin grades III, IV, and V) treated in two centers in Germany between January 1989 and February 2023. The analyzed data included demographic, clinical, morphological, and neurological data. A total of 150 cases (60%) were classified as Spetzler-Martin grade III, 82 cases (32.8%) were classified as grade IV, and 18 cases (7.2%) were classified as grade V. Eighty-seven cases (34.8%) presented with hemorrhage. The devascularization percentages achieved were <50% in 24 (9.6%), 50-80% in 55 (22%), and >80% in 171 (68.4%) cases. The average number of sessions was 5.65 ± 5.50 and 1.11 ± 0.32 endovascular and surgical procedures, respectively, and did not significantly differ by rupture status. Death or dependency (mRS score ≥ 3) after the last follow-up was observed in 18.8% of patients and was significantly associated with age > 80 years and poor baseline neurological condition. The complete resection rate was 82.3% and was significantly associated with age > 80 years, large nidus, and deep venous drainage. Permanent disabling neurological deficit after at least 3 months of follow-up was diagnosed in 13.2% of patients and was significantly associated with age > 80 years and infratentorial locations. A multi-stage treatment for high-grade AVMs is feasible for selected cases but comes at a functional cost. The devascularization percentage was not associated with the investigated outcomes. Age > 80 years was associated with poor safety and effectiveness outcomes; consequently, this treatment should be offered only in exceptional circumstances.

A Study of R2T14B (R = Y, Nd, Gd, Ho, T = Fe, Co) Hard Magnetic Materials via Magnetometry and Atomic Force Microscopy

Magnetometry and atomic force microscopy (AFM) were used to study the magnetic and structural properties of the R–Fe–B-type (R = Y, Nd, Gd, Ho) alloys. The alloys were synthesized by means of induction melting. The nanocrystalline state of the R–Fe–B-type alloys was reached, mainly, by melt spinning (MS). A multistage treatment of R–Fe–B-type alloys, which included severe plastic deformation of melt-quenched ribbons and subsequent heat treatment, was also used. The surface morphology of samples was studied in detail to interpret the observed magnetic hysteresis loops of the samples. It was found that the type of rare earth ion and treatment methods had the most important influence on the microstructure and magnetic properties.

Simultaneous removal of fluoride and phosphate from semiconductor wastewater via chemical precipitation of calcium fluoride and hydroxyapatite using byproduct of recycled aggregate

Semiconductor wastewater with high concentrations of fluoride and phosphate is an environmental issue that cannot be ignored. Moreover, the byproduct of recycled aggregates, concrete fines, cannot be reused in concrete manufacturing, which is a key issue to address for the sustainable development of the concrete industry. The objective of this study was to tackle the crucial environmental issues of these two industries by developing concrete fines as an alternative material to treat semiconductor wastewater. The chemical precipitation of calcium fluoride and hydroxyapatite in the presence of concrete fines was determined as the mechanism underpinning the removal of fluoride and phosphate in wastewater. Owing to the wide range of contaminant concentration and solution pH and the possibility of multi-stage treatment, the effects of the initial contaminant concentration (F: 100–1000 mg/L; P: 20–200 mg/L) and solution pH (pH: 2–7) on the removal reactions were determined. The highest F and P removal percentages were more than 99%, and the final F and P concentrations met the effluent standard (F: 15 mg/L, P: 1.3 mg/L). The removal reactions of F and P are generally in competition, and the removal of F has priority over the removal of P. The pseudo-second-order model can describe the kinetics of the removal reactions well. The formation of fluorapatite can reduce the F concentration below the concentration achievable by CaF2 precipitation alone. Furthermore, using the byproduct of recycled aggregates instead of conventional chemicals to treat semiconductor wastewater is promising in terms of reducing CO2 emissions, and prospective applications are discussed. This study can lead to the development of a sustainable and clean process for semiconductor wastewater treatment using byproducts from the concrete industry.

EXPERIENCE OF USING ACID TREATMENTS IN THE OIL FIELD SUWAYDIYA (SYRIA)

Link for citation: Mohammad Almohammad Alnayef, Zain Alabidin Dalfi Abd Ali Khalaf, Gnidan E.V. Experience of using acid treatments in the oil field Suwaydiya (Syria). Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 7, рр. 50-58. In Rus. Relevance of the research is caused by the need to increase oil recovery from wells developed in the fields of Syria, in the carbonate reservoirs of the Massif and Shiranish formation, for which there is a natural drop in production rates due to decrease in reservoir pressure, water cut, opening of reservoirs with low reservoir properties and increase in the share of hard-to-recover reserves. The main aim of the study is to analyze the results of acid treatments to improve oil recovery in the field of Suwaydia, Syria. The object of study is the carbonate complexes in the Upper Cretaceous deposits of the Massif formation and the Shiranish formation, Syria. Methods: review of domestic and foreign experience in treating the bottomhole formation zone using acid compositions and analysis of production, technological, lithological, geological, geophysical, and field data of wells treated with acids. Results. The paper introduces the advantages of the acid treatments method, such as improving the reservoir permeability and decreasing the skin factor by increasing the pore space and fracture channels, as well as removing the filter cake and various inorganic sediments that prevent oil flow. The undesirable effects of acid treatments: corrosion, secondary sedimentation, water cut, are indicated. The geological and physical conditions of the well and reservoir for choosing a treatment technology are considered. They are: reservoir temperature, filtration, and reservoir properties of rocks, granulometric (fractional) and mineralogical composition of rocks, chemical composition of reservoir fluids. The main directions of measures for solving geological and technological complications that arise during acid treatments using inhibitors, new multicomponent compositions of acid agents, special additives, and multi-stage treatments are noted. The paper introduces the technology and results of the application of acid treatments: hydrochloric acid treatment and foam hydrochloric acid treatment of the bottomhole zone of wells located in the north-east of the Syrian Arab Republic, which belong to the two oil field – Suwaydia and Zarba – of the Al-Hasakah Oil Fields Administration. It was noted that the use of a simple hydrochloric acid treatment of several wells did not lead to the predicted increase in oil recovery, and the use of an acid mixture (HCL at a concentration of 15 %, HF at a concentration of 3 %) in well no. 462 of the Suwaydia oil field showed an increase in productivity of 1,5 times. Recommendations are given for improving acid treatments at the Suwaydia, Syria fields to intensify oil production.

Treatment of Landfill Leachate Reverse Osmosis Concentrates by Advanced Oxidation-Heterotrophic Nitrification-Aerobic Denitrification Combination process.

This study aimed to develop a multistage treatment system for highly toxic wastewater named reverse osmosis concentrates of landfill leachate. Therefore, a combination of the ammonia stripping process (ASP), catalytic ozone oxidation process (COP), and heterotrophic nitrification-aerobic denitrification process (HNADP) was proposed and the quality of effluent was evaluated for the concentration of chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), and total nitrogen (TN). ASP had moderate removal efficiency of NH4+-N, and TN in the effluent. COP was catalyzed by cerium-supported-activated carbon achieved good performance in disposal of COD. The effluent of HNADP had the most significant removal efficiency of COD, NH4+-N, and TN. As a result, the effluent of combined process successfully met the discharge standards for NH4+-N and TN according to Table 1 of GB 16889-2008 in China. To investigate the microbial mechanism of pollutant removal in HNADP, 16S rRNA high-throughput sequencing was performed and the results suggested that the relative abundance and diversity of microorganisms fluctuated with the changes of COD/TN ratio in HNADP. Truepera and Halomonas were identified as the key genera involved in the simultaneous degradation of COD and nitrogen-containing pollutants, the functional genes (hao, amoA, nirS, and nirK) were predicted in nitrification and denitrification process. Overall, this study demonstrates a feasible multistage system for treatment of concentrates and propose that further explorations of combined techniques may lead to even more satisfactory removal efficiencies.

Multistage treatment of bamboo powder waste biomass: Highly efficient and selective isolation of lignin components

Bamboo pulp and papermaking produce a lot of bamboo powder waste, and its resource utilization is of great significance for biomass refining and environmental protection. Here, we propose an integrated approach involving mechanical activation, hydrothermal extraction, and deep eutectic solvents (DESs) multiple delignification for the efficient separation of bamboo powder. Among seven carboxylic acids based DESs, choline chloride (ChCl)-lactic acid (La) DES (1:1) is the most effective, with over 78.0% lignin removal and 88.9% cellulose retained after mechanical-hydrothermal (180 °C, 5 h)-DES (110 °C, 12 h) treatment. Notably, 84.7% of delignification is achieved after three times of ChCl-La DES treatment at 70, 90, and 110 °C respectively. The delignification rate is negatively correlated with the amount of carboxyl group in the DESs. The lower the pKa value, the higher the delignification rate. Additionally, the selectivity for lignin is improved with decreasing solvent polarity. DES treatment effectively degrades the guaiacyl unit lignin fractions and disrupts several β-aryl-ether bonds (e.g., β-O-4, β-β, and β-5). Furthermore, DESs exhibit good recyclability, with less than 10% reduction in delignification after three cycles. Theory calculations confirm that ChCl-carboxylic acid DESs could compete with lignin to break hydrogen bonds in lignocellulosic biomass by providing their chloride, hydroxyl, and carboxyl groups. Overall, this study demonstrates the practical significance of multistage treatment for the effective fractionation of biomass into its three components.

Multidisciplinary approach to the treatment of children with congenital cleft lip and palate in Ukraine

Children with congenital cleft lip and palate (CLP) develop a composite complex of anatomical, functional and aesthetic disorders that increase with growth and require comprehensive and multi-stage treatment. Treatment and diagnostic measures require a multidisciplinary approach to overcome the identified problems. The main task of orthodontic support for children with CLP at the stages of primary surgical interventions is aimed at preventing orthognathic surgical correction in the future, by optimizing the choice and tactics of orthodontic treatment within the framework of multidisciplinary comprehensive rehabilitation measures. The purpose of the work is the substantiation, approval and introduction into clinical practice of a complex of medical and diagnostic measures aimed at the rehabilitation of children with CLP. It confirmed that providing the necessary conditions for sucking creates optimal conditions for surgical intervention on the lip and palate. The tactics of orthodontic treatment depended on the period of development of the dentognathic apparatus, age, type of cleft, staging, timing and volume of surgical interventions, quality and methods of surgery, severity of deformations in the transversal and sagittal planes and components of the symptom complex of anomalies and deformations complicating the pathology, psychological and emotional child state, factors of parents and patients communication with the doctor, social and economic components. Removable and fixed orthodontic appliances are used in most cases at the initial stage of treatment for the treatment of dentognathic deformities, obtaining satisfactory sagittal and vertical overlap and normalization of transversal ratios. A separate area of rehabilitation was prevention and treatment of diseases of hard tissues of teeth and periodontal tissues. Speech therapy and psychological support started from 2–3 months. The proposed complex of treatment and diagnostic measures, determined in time, terms, sequence and volume, aimed at the rehabilitation of children with CLP, made it possible to obtain positive anatomical, functional and aesthetic results in 87.6% of children. Keywords: therapeutic and diagnostic measures, orthodontic treatment, speech therapy and psychological support, rehabilitation algorithm.

Renal Artery Stenosis Complicated with Primary Aldosteronism.

Primary aldosteronism (PA) is a typical example of low renin hypertension, whereas renal artery stenosis (RAS) is a classic form of high renin hypertension. PA and RAS occurring simultaneously in a patient is challenging to diagnose. We report a 32-year-old woman with a 12-year history of resistant hypertension. She was identified to have elevated plasma aldosterone and renin levels with normal aldosterone/renin ratio (ARR). Imaging examinations identified bilateral adrenal thickening and subtotal occlusion of the anterior segment of the left renal artery. Adrenal venous sampling was performed and indicated the existence of unilateral aldosterone over-secretion. It may suggest that even though RAS led to non-suppressed renin, adrenal venous sampling remains to be an applicable approach to establish the diagnosis of aldosterone-producing adenomas, although the diagnostic value of ARR may be compromised due to non-suppressed renin level. The patient underwent a two-stage treatment. First, stenosis of the left renal artery was dilated by percutaneous transluminal renal balloon angioplasty. Two months later, laparoscopic complete left adrenalectomy was performed. Hematoxylin-eosin staining and CYP11B2 immunostaining suggested that this tumor was an aldosterone-producing adenoma. After the two-stage treatment, her blood pressure decreased to a normal level without antihypertensive drugs. This case report raises our awareness of the simultaneous occurrence of RAS and PA. Under this condition, ARR could lead to a false-negative PA. Adrenal venous sampling is warranted to achieve a confirmed diagnosis. For subjects with complex etiologies of secondary hypertension, multi-stage treatment may be required.

New Thermal Insulation Materials from Waste of Mechanical Processing of Wood

The article describes the conditions for obtaining new thermal insulation materials from the waste of mechanical processing of soft hardwood wood. The recommendations for the production of new resource-saving technologies of gypsum-wood and chip-and-glue composites are justified, which makes it possible to dispose of waste from the processing of soft hardwood wood. It was found that the birch pulp extract, along with cellulose and lignin, contains d-erythrosis, which is easily washed out of the wood with water or a solution of "mineralizer" and gets into the cement dough, which leads to a slowdown in hardening and a decrease in compressive strength. It is shown that the existing technological processes for eliminating the negative influence of saccharides on the strength of wood aggregate composites are complex, requiring multi-stage treatment of the aggregate with various chemicals or long-term exposure. A method based on the use of binders that do not interact with extractable substances, such as gypsum or urea-formaldehyde glue, is proposed. By scanning electron microscopy, it was found that the structure of the gypsum-wood composite varies depending on the sequence of input components. The nature of the effect of microcrystalline cotton cellulose on the change in the physical and mechanical properties of the gypsum-particle composite using cavitation-treated sawdust was revealed and its optimal dosage was determined. The regression dependences of the influence of the consumption of wood chips and glue on the compressive strength of the chip-and-glue composite were obtained by the experimental planning method.

Physicochemical Technique in Municipal Solid Waste (MSW) Landfill Leachate Remediation: A Review

Leachate generation is among the main challenging issues that landfill operators must handle. Leachate is created when decomposed materials and rainwater pass through the waste. Leachate carries many harmful pollutants, with high concentrations of BOD, COD, colour, heavy metals, ammoniacal nitrogen (NH3-N), and other organic and inorganic pollutants. Among them, COD, colour, and NH3-N are difficult to be completely eliminated, especially with a single treatment. They should be handled by appropriate treatment facilities before being safely released into the environment. Leachate remediation varies based on its properties, the costs of operation and capital expenditures, as well as the rules and regulations. Up until now, much scientific and engineering attention was given to the development of comprehensive solutions to leachate-related issues. The solutions normally demand a multi-stage treatment, commonly in the form of biological, chemical, and physical sequences. This review paper discussed the use of contemporary techniques to remediate landfill leachate with an emphasis on concentrated COD, colour, and NH3-N levels with low biodegradability that is normally present in old landfill or dumping grounds in developing countries. A semi-aerobic type of landfill design was also discussed, as this concept is potentially sustainable compared to others. Some of the challenges and future prospects were also recommended, especially for the case of Malaysia. This may represent landfills or dumpsites in other developing countries with the same characteristics.

Interim monitoring of sequential multiple assignment randomized trials using partial information.

The sequential multiple assignment randomized trial (SMART) is the gold standard trial design to generate data for the evaluation of multistage treatment regimes. As with conventional (single-stage) randomized clinical trials, interim monitoring allows early stopping; however, there are few methods for principled interim analysis in SMARTs. Because SMARTs involve multiple stages of treatment, a key challenge is that not all enrolled participants will have progressed through all treatment stages at the time of an interim analysis. Wu etal. (2021) propose basing interim analyses on an estimator for the mean outcome under a given regime that uses data only from participants who have completed all treatment stages. We propose an estimator for the mean outcome under a given regime that gains efficiency by using partial information from enrolled participants regardless of their progression through treatment stages. Using the asymptotic distribution of this estimator, we derive associated Pocock and O'Brien-Fleming testing procedures for early stopping. In simulation experiments, the estimator controls type I error and achieves nominal power while reducing expected sample size relative to the method of Wu etal. (2021). We present an illustrative application of the proposed estimator based on a recent SMART evaluating behavioral pain interventions for breast cancer patients.

Strategy of complex treatment of the neuroischemic form of diabetic foot syndrome in critical ischemia and in presence of resistant forms of purulent infection pathogens using bacteriophages on the example of clinical observation

The article presents a clinical observation illustrating the multi-stage treatment of purulent-necrotic lesions of the diabetic foot syndrome in the presence of resistant flora and critical ischemia of the affected limb. The importance of teamwork in providing medical care to this category of patients, as well as the need to use adjuvant therapy, in particular, bacteriophages, in the complex treatment, is demonstrated

Retrofitting a full-scale multistage landfill leachate treatment plant by introducing coagulation/flocculation/sedimentation and ultrafiltration process steps.

Considering that landfilling still remains among the most commonly used methods for the confrontation of solid wastes, effective methods should be applied to treat the leachate generated, due to its recalcitrant nature. In this work, a full-scale system consisting of two SBRs operating in parallel (350 m3 each) and two activated carbon (AC) columns operating in series (3 m3 each) was retrofitted by introducing a coagulation/flocculation/sedimentation (C/F/S) unit of 7.8 m3 and an ultrafiltration (UF) membrane of 100 m2 to effectively treat landfill leachate. The raw leachate was characterized by high COD and NH4+-N concentration, i.e., 3095 ± 706mg/L and 1054 ± 141mg/L respectively, a BOD/COD ratio of 0.22, and high concentrations of certain heavy metals. Leachate processing in this retrofitted multistage treatment system resulted in total COD removal efficiency of 89.84%, with biological treatment, C/F, UF, and AC contributing 46.31%, 4.68%, 15.98%, and 22.87% to the overall organic content removal. The retrofitted scheme achieved an overall NH4+-N and TKN removal of 92.03% and 91.75% respectively, attributed mostly to the activity of an effective nitrifying community. Color number (CN) was reduced by 26.96%, 10.29%, 15.94%, and 5.39% after the activated sludge, the C/F, the UF, and the AC adsorption process respectively, corresponding to a 58.91% overall decrease. Regarding heavy metal removal, all elements examined, apart from Ni, i.e., effluent As, Cd, Co, Cr, Cu, Hg, Mg, Mn, and Pb, were below the legislative limits set by the national authorities for restricted or unrestricted irrigation. Lastly, total operating expenses (OPEX) were estimated as equal to 72,687 €/year or 6.64 €/m3.

Phototoxicity of temoporfin-loaded cyclodextrin nanosponges in stroma-rich three-dimensional models of head and neck cancer

Photodynamic therapy is a multistage treatment, in which cancerous and precancerous cells are destroyed by light activation of a drug (photosensitizer). For a long time, high cellular uptake of the photosensitizer was an important indication of efficient PDT, while the role of photosensitizer penetration was unexplored. Recently, we have demonstrated that nanosponges based on hypercrosslinked β-cyclodextrin polymer (β-CDp) can increase drug penetration at the cost of their cellular uptake in multicellular spheroids, paving the way for studying the impact of penetration on PDT response.In the present work, we used β-CDp nanosponges to deliver temoporfin to the depth of stroma-rich head and neck cancer multicellular spheroids and then assess PDT response. Encapsulation of temoporfin in β-CDp nanosponges resulted in increased penetration and more uniform distribution of temoporfin in spheroids, however, was also associated with a two-fold reduction of cellular uptake compared to the free drug. Nevertheless, we demonstrated that β-CDp nanosponges possess similar PDT efficiency as the free drug in stroma-rich head and neck cancer multicellular spheroids. Overall, this study suggests that β-CDp nanosponges are a strong candidate for in vivo studies as they have fewer “off-target” effects while providing a similar therapeutic response.

ENDOVASCULAR DIAGNOSTICS AND TREATMENT OF HEMORRHAGES IN MILITARY AND CIVILIAN PATIENTS FOLLOWING ABDOMINAL SURGERY.

The aim: The retrospective analysis of the angiographic picture and clinical results of endovascular treatment of patients with postoperative abdominal and gastrointestinal bleeding was carried out. Materials and methods: The results of 447 endovascular diagnostic and therapeutic interventions in 391 patients (46 military and 345 civilians) with postoperative bleeding performed from 2012 to 2022 were studied. According to computer tomography with contrast enhancement, the source of bleeding was identified in 216 (67.7%) cases. Results: In 345 (88.2%) patients, it was possible to reliably identify the source of bleeding on angiography. In 46 (11.8%) patients with an unexplained source of bleeding, the target arterial pool was determined on the basis of localization, volume, and features of surgical intervention and considered as preventive interventions. A total of 447 endovascular hemostatic interventions were performed on 391 patients. A stent graft was installed in 27 patients, 420 embolization were performed in 364 patients. Thus, in 43 (11.0%) patients, embolization was performed repeatedly, in 12 cases - three times, in 1 case - four times. In 16 cases (15 cases of prophylactic embolization), endovascular hemostasis was ineffective and required subsequent surgical intervention. Conclusions: Endovascular interventions are an effective method of diagnosis and treatment of postoperative abdominal bleeding. Prophylactic embolization allows you to prevent the recurrence of postoperative bleeding with an instrumentally undiagnosed source, however, you need to be prepared for the multi-stage treatment aimed at sequentially shutting down the collateral blood supply to the damaged area.

Multistage surgical treatment of early-onset scoliosis in patients with Ehlers-Danlos syndrome: A series of observations

BACKGROUND: EhlersDanlos syndrome (EDS) is a group of hereditary pathological conditions caused by various disorders of collagen biosynthesis. The study analyzed the results of multistage surgical treatment of early scoliosis in patients with severe spinal deformities due to EDS. No similar observations have been found in the literature.&#x0D; CLINICAL CASES: Four patients with a verified diagnosis of EDS and progressive spinal deformities were subjected to multistage surgical treatment using the VEPTRII instrumentation, which included periodic distractions and final spinal fusion with segmental instrumentation. Stage-by-stage surgical treatment was initiated from the age of 3 to 6 years. In 3 of 4 cases, the kyphotic component prevailed over the scoliotic one (86140 vs. 21110). The number of staged distractions ranged from 6 to 10. The age of the final stage (correction and dorsal fusion) was 914 years (surgery was performed in three of four cases). The primary correction was 3056, the loss of correction before the final stage was 1435, and the correction during the final stage was 2240. A significant correction of the frontal and sagittal imbalances of the spine was noted. Blood loss during the final fusion was 540750 mL, and the operation time was 310350 min. Ten complications occurred, of which 9 were associated with implants and disappeared during staged distractions. No neurological and vascular complications occurred.&#x0D; DISCUSSION: Scoliosis occurring in the first decade of life in patients with EDS is characterized by early-onset, rapid progression, and tendency to form a significant kyphotic component of spinal deformity.&#x0D; CONCLUSIONS: Multistage treatment of early scoliosis in patients with EDS using VEPTRII tools allows for obtaining quite satisfactory results and has not severe complications. The final fusion gives a significant corrective effect; however, new research and accumulation of data are needed to optimize the treatment process.

Media coalescence filtration as a novel method for pretreatment of refinery wastewater

Refinery wastewater is not only large in volume but also complex in composition. It requires multi-stage treatment to achieve discharge or reuse targets. Pretreatment plays an important role as a front-end treatment. In conventional pretreatment technologies, petroleum removal and suspension removal are carried out through inclined plate settlement combined with two-stage air flotation. This poses problems such as high energy and chemical consumption and large outputs of hazardous waste. In this study, a short-process physical pretreatment technology is designed in conjunction with combined fiber coalescer (CFC) and granular media filter (GMF). The results of the pilot test show that with no added chemicals, the treated refinery wastewater is clear and translucent, and the petroleum and suspended solids content could be reduced to less than 20 mg/L, which falls within the acceptable range of the biochemical influent index. This process could greatly reduce the generation and emission of scum and volatile organic compounds (VOCs) and provides a new technique for the low-carbon pretreatment of refinery wastewater.