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1.
BMC Prim Care ; 25(1): 343, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39300370

RESUMEN

BACKGROUND: Medicine retailers, considered here as any person or setting dedicated to the sale of retail medicines, fill an important gap in terms of access to healthcare in areas where population are not covered by universal healthcare schemes. In Goma in the Democratic Republic of the Congo, such retailers have proliferated and are consulted as the first port of call by more than half of the population, playing therefore a key role as an alternative source of healthcare for any type of health condition. The objective of this study is to understand people of Goma's rationale for using the medicine retailers over the formal healthcare system. METHODS: Twelve focus groups, gathering 147 participants in total, were conducted in four worship communities, covering the most common faiths practised in Goma. Three focus group discussions were organised per worship community: one with fathers, another with mothers, and another with chronic patients and/or highly vulnerable people. We used a qualitative and inductive approach to analyse the participants' practices and perceptions in terms of their use of medicine retailers. We identified central categories explaining the reasons for using medicine retailers and the choice of a specific medicine retailer. RESULTS: When facing a health problem, most of the participants in our study tended to first buy medicines at medicine retailers because it was cheap, quick, and easily accessible. Most were aware of the risks and limitations of such practices and had developed a number of mitigation strategies in order to reduce those risks: evaluating medicine retailers' expertise; developing a "medical expertise"; and seeking proactively out empathetic care. CONCLUSIONS: People in Goma make a conscious and rational choice when resorting to medicine retailers as it is seen as the least-worst option in a complex situation. In order to reduce the risks, they have developed a number of mitigation strategies. Future research should focus on the organisation of medicine retailers as a professional group to improve their supervision in a sensitive context such as Goma and on modalities to articulate them to the formal health system to guarantee a financial accessibility to healthcare for all.


Asunto(s)
Comercio , Grupos Focales , Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Accesibilidad a los Servicios de Salud , Investigación Cualitativa , Adulto Joven
2.
Euro Surveill ; 29(38)2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39301745

RESUMEN

Between January and August 2024, mpox cases have been reported in nearly all provinces of the Democratic Republic of the Congo (DRC). Monkeypox virus genome sequences were obtained from 11 mpox cases' samples, collected in July-August 2024 in several health zones of Kinshasa. Characterisation of the sequences showed subclades Ia and Ib co-circulating in the Limete health zone, while phylogenetic analyses suggested multiple introductions of the two subclades in Kinshasa. This illustrates the growing complexity of Clade I mpox outbreaks in DRC.


Asunto(s)
Brotes de Enfermedades , Monkeypox virus , Mpox , Filogenia , República Democrática del Congo/epidemiología , Mpox/epidemiología , Mpox/virología , Humanos , Monkeypox virus/genética , Monkeypox virus/aislamiento & purificación , Genoma Viral , ARN Viral/genética , Masculino , Análisis de Secuencia de ADN
3.
Heliyon ; 10(17): e37469, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-39296208

RESUMEN

As the textile industry expands, more industrial waste effluents are released into natural water streams, prompting the research and development of innovative materials for the remediation of environmental issues. In this research, a direct precipitation and hydrolysis method were used to synthesize ZnO and TiO2 nanoparticles, respectively that were utilized to investigate the photocatalytic activity of Congo Red (CR) dye. Afterward, the crystallite size was computed from the data of the X-ray diffractometer (XRD), and utilizing several models (Scherrer equation, LSLMSE, Monshi-Scherrer equation, Williamson-Hall model, Size-strain plot method, Halder-Wagner model, Sahadat-Scherrer model). Among these models, the size-strain plot model yields the most accurate crystal size (45.31 nm) for ZnO nanoparticles and the Halder-Wagner model (2.44 nm) for TiO2 nanoparticles. Scanning Electron Microscope exhibited the spherical shape of nanoparticles (ZnO, and TiO2) with particle size (less than 151 nm). The absorption spectrum from Fourier transform infrared (FTIR) spectroscopy confirmed the formation of nanoparticles (ZnO, and TiO2). Thereafter, the photocatalytic activity of the ZnO-TiO2 nanocomposite was evaluated by using Congo Red (CR) dye under different process variables, such as catalyst dose, time, initial dye concentration, pH, radical scavenging ability, and reusability. The best degradation (90 %) was recorded at 180 min time intervals using a 0.2 g catalyst dose with a 20 ppm CR concentration at pH 9.

4.
Arch Microbiol ; 206(10): 402, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39261342

RESUMEN

A global water crisis is emerging due to increasing levels of contaminated water and decreasing clean water supply on Earth. This study aims to address the removal of azo dye from wastewater to enable its reuse. Recently, utilizing microorganisms has been proven to be a practical choice for the remediation of azo dyes in wastewater. Hence, in this study, we employed a preformed biofilm of Pseudomonas aeruginosa on a solid support (called substrate) to degrade azo dyes. This process offers several advantages, such as stability, substrate portability, more biofilm production in less time, and efficient utilization of enzymes for remediation. From 50 ppm of initial Congo Red concentration, 75.74% decolorization was achieved within ten h using a preformed biofilm on a coverslip. A maximum of 52.27% decolorization was achieved using biofilm during its formation after 72 h of incubation. The Fourier-transform infrared (FTIR) spectroscopic analysis of Congo Red dye before and after remediation revealed a significant change in peak intensity, indicating dye degradation. Phytotoxicity studies performed by seed germination with Vigna radiata revealed that, after 5-7 days, almost 40% more seeds with longer root and shoot lengths were germinated in the presence of treated dye compared to the untreated one. This data indicated that the harmful Congo Red was successfully degraded to a non-toxic product by Pseudomonas aeruginosa biofilm grown on a glass substrate.


Asunto(s)
Biodegradación Ambiental , Biopelículas , Rojo Congo , Pseudomonas aeruginosa , Biopelículas/crecimiento & desarrollo , Rojo Congo/metabolismo , Pseudomonas aeruginosa/fisiología , Pseudomonas aeruginosa/metabolismo , Aguas Residuales/microbiología , Contaminantes Químicos del Agua/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Colorantes/metabolismo , Germinación
5.
Int J Biol Macromol ; : 135313, 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39242000

RESUMEN

Herein, we report two different adsorbents from spherical nanocellulose (SNC) in successive steps, for the adsorption of Hg2+ ions and Congo red (CR). Cellulose extracted from pine needles was subsequently converted to SNC through mixed acidic hydrolysis. As-obtained SNC was esterified with methionine at C6 of the anhydroglucose unit of SNC to SNC-methionine ester (SNC-ME). The amino group of methionine residue in SNC-ME was protonated to SNC-PME with positive surface charge. The SNC-ME and SNC-PME were evaluated as Hg2+ ions and CR adsorbents, respectively. The SNC, SNC-ME, SNC-PME, Hg2+-loaded SNC-ME, and CR-loaded SNC-PME were characterized by FTIR, XRD, XPS, Zeta potential, BET, FESEM, EDS, and surface charge analysis. SNC-ME showed Hg2+ ions removal efficiency of 94.8 ±â€¯1.9 % in 40 min, while SNC-PME showed CR removal efficiency of 96.1 ±â€¯3.8 % in 90 min. The adsorption data of both the adsorbents fitted best into pseudo-second order kinetic and Langmuir isotherm. The maximum adsorption capacity of SNC-ME for Hg2+ ions was 211.5 ±â€¯3.1 mg/g and that of SNC-PME for CR was 281.1 ±â€¯7.1 mg/g. The astounding recyclability of the adsorbents for ten repeat cycles with significant cumulative adsorption capacity of 760.9 ±â€¯12.8 mg/g for Hg2+ ions and 758.8 ±â€¯12.7 mg/g for CR endorses their spectacular potentiality for wastewater treatment.

6.
BMC Endocr Disord ; 24(1): 174, 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39223506

RESUMEN

BACKGROUND: The European Thyroid Association Thyroid Imaging Data and Reporting Systems (EU-TIRADS) is widely used in the risk stratification of thyroid nodule malignancy. However, data on the subject in Sub-Saharan Africa are limited. The objective of this study is to evaluate the clinical, sonographic and histopathological concordance of thyroid nodules in the diagnosis of thyroid cancer. METHODS: This was an analytical cross-sectional study that examined the clinical, ultrasound and pathological data of 61 patients from 4 hospitals in the city province of Kinshasa over a period of 24 months, from June 01, 2020 to May 31, 2022. RESULTS: Of the 61 patients, their mean age was 47.38 ± 8.8 years. The mean clinical score of the patients was 3.4 ± 0.84 with the extremes ranging from 1 to 5. The majority of the patients were classified as having an intermediate risk, ie 85.2% of the cases. It was noted that 41% of the nodules had a high risk according to the EU-TIRADS score and 8.2% of the nodules were malignant after histopathological analysis. The ROC curves reported at the diagnosis of malignancy show an area under the curve of 0.709 with 95% CI (0.486-0.931), a Youden index of 0.769 for the clinical score, and an area under the curve of 0.830 with 95% CI (0.605-0.995), a Youden index of 0.772 for the EU-TIRADS score. CONCLUSION: In a low-income country, a well-performed thyroid ultrasound and the well-applied clinical score could be an important tool in the selection of thyroid nodules suspected of malignancy and requiring histopathological examination to avoid excessive acts in the patient.


Asunto(s)
Neoplasias de la Tiroides , Nódulo Tiroideo , Ultrasonografía , Humanos , Nódulo Tiroideo/patología , Nódulo Tiroideo/diagnóstico por imagen , Estudios Transversales , Masculino , Femenino , Persona de Mediana Edad , Ultrasonografía/métodos , República Democrática del Congo/epidemiología , Adulto , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/diagnóstico por imagen , Neoplasias de la Tiroides/epidemiología , Pronóstico , Glándula Tiroides/patología , Glándula Tiroides/diagnóstico por imagen , Estudios de Seguimiento
7.
Primates ; 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39283353

RESUMEN

Many non-human primates form heterospecific associations to increase benefits resulting from group living like antipredation defence and increased foraging efficiency while avoiding costly resource competition that usually arises from large conspecific groups. Previous studies provided profound insight into how these benefits are obtained and what behavioural changes might be elicited through association formation. What remains widely unknown are factors that could account for intra-specific variation in association patterns. For instance, we are still widely lacking a comprehensive assessment of how group size and seasonality affect heterospecific associations across larger number of groups within a species. The current study monitored more than 20 groups of putty-nosed monkeys (Cercopithecus nictitans), a forest guenon known to be frequently in association with other monkey species, for 37 months in the Nouabalé-Ndoki National Park, Republic of Congo. Amongst the five primate species observed in association with C. nictitans, grey-cheeked mangabeys (Lophocebus albigena) and crowned monkeys (C. pogonias) were the most frequently encountered association partners. We did not find any effect of seasonality on association rates. However, larger C. nictitans groups were substantially more in association with L. albigena and C. pogonias than smaller groups during the main dry season. We argue that our findings suggest a major impact of antipredation benefits of heterospecific troops including C. nictitans during periods of increased vulnerability. We discuss how knowledge about variations in association patterns may help to adjust conservation strategies.

8.
Molecules ; 29(17)2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39274938

RESUMEN

The adsorption properties of microporous carbon materials modified with iron citrate were investigated. The carbon materials were produced based on resorcinol-formaldehyde resin, treated in a microwave assisted solvothermal reactor, and next carbonized in the tube furnace at a temperature of 700 °C under argon atmosphere. Iron citrate was applied as a modifier, added to the material precursor before the synthesis in the reactor, in the quantity enabling to obtain the nanocomposites with C:Fe mass ratio equal to 10:1. Some samples were additionally activated using potassium oxalate or potassium hydroxide. The phase composition of the produced nanocomposites was determined using the X-ray diffraction method. Scanning and transmission electron microscopy was applied to characterize the changes in samples' morphology resulting from the activation process and/or the introduction of iron into the carbon matrix. The adsorption of nitrogen from gas phase and dyes (methylene blue and congo red) from water solution on the obtained materials was investigated. In the case of methylene blue, the adsorption equilibrium isotherms followed the Langmuir isotherm model. However, in the case of congo red, a linear dependency of adsorption and concentration in a broad equilibrium concentration range was found and well-described using the Henry equation. The most efficient adsorption of methylene blue was noticed for the sample activated with potassium hydroxide and modified with iron citrate, and a maximum adsorption capacity of 696 mg/g was achieved. The highest congo red adsorption was noticed for the non-activated sample modified with iron citrate, and the partition coefficient for this material equaled 171 dm3/g.

9.
Emerg Infect Dis ; 30(10)2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39255234

RESUMEN

We used published data from outbreak investigations of monkeypox virus clade I in the Democratic Republic of the Congo to estimate the distributions of critical epidemiological parameters. We estimated a mean incubation period of 9.9 days (95% credible interval [CrI] 8.5-11.5 days) and a mean generation time of 17.2 days (95% CrI 14.1-20.9 days) or 11.3 days (95% CrI 9.4-14.0 days), depending on the considered dataset. Presymptomatic transmission was limited. Those estimates suggest generally slower transmission dynamics in clade I than in clade IIb. The time-varying reproduction number for clade I in the Democratic Republic of the Congo was estimated to be below the epidemic threshold in the first half of 2024. However, in the South Kivu Province, where the newly identified subclade Ib has been associated with sustained human-to-human transmission, we estimated an effective reproduction number above the epidemic threshold (95% CrI 0.96-1.27).

10.
Environ Monit Assess ; 196(10): 923, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39259367

RESUMEN

Two polyurethane polyaniline nanocomposites have been synthesized using two in situ polymerization routes of dried and wet bases to valorize the polyurethane waste. The physical and chemical properties of polyurethane-based nanocomposites were compared using SEM, XRD, FTIR, and Zeta potential. SEM images showed that the average particle size of the dried-based composite was 56 nm, while the wet-based composite had an average size of 75 nm. The separation efficiency for methylene blue (MB) and Congo red (CR) dyes was evaluated against free polyurethane foam waste. It was evident that pure polyurethane (PPU) achieved only 4.79% and 16.71% removal for MB and CR, respectively. These dye decontamination efficiencies were enhanced after nano polyaniline decoration of polyurethane foam either through dried base polymerization (DPUP) or wet base polymerization (WPUP). WPUP composite records 11.23% and 85.99% for MB and CR removal, respectively, improved to 26.69% and 90.07% removal using DPUP composite for the respective dyes. The adsorption kinetics, isotherms, and thermodynamics were investigated. The experimental results revealed the pseudo-second-order kinetic model as the most accurately described kinetics model for both CR and MB adsorption. The Langmuir model provided the best fit for the data, with maximum adsorption capacities of 110.98 mg/g for CR and 26.86 mg/g for MB, with corresponding R-squared values of 0.9974 and 0.9608, respectively. Regeneration and reusability studies of PPU, WPUP, and DPUP showed effective reusability, with DPUP displaying the highest adsorption capacity. These results aid in creating eco-friendly and cost-efficient adsorbents for dye removal in environmental sanitation.


Asunto(s)
Compuestos de Anilina , Colorantes , Nanocompuestos , Poliuretanos , Contaminantes Químicos del Agua , Poliuretanos/química , Compuestos de Anilina/química , Colorantes/química , Contaminantes Químicos del Agua/química , Nanocompuestos/química , Adsorción , Azul de Metileno/química , Eliminación de Residuos Líquidos/métodos , Descontaminación/métodos , Cinética , Rojo Congo/química
11.
Vet Parasitol Reg Stud Reports ; 54: 101089, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39237233

RESUMEN

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral zoonosis caused by a Nairovirus, Crimean-Congo hemorrhagic fever virus (CCHFV). Despite its wide geographical distribution, the epidemiology of CCHF in northern Africa is incompletely understood and its occurrence in Algeria is virtually unknown. The present survey aimed to determine the prevalence of CCHF antibodies and to identify the potential risk factors associated with CCHFV seropositivity among the one-humped camel (Camelus dromedarius) in southern Algeria. A total of 269 camels selected randomly from slaughterhouses in three wilayas were employed in the study. Sera sampled were tested for the presence of CCHFV-specific IgG antibodies using enzyme-linked immunosorbent assay (ELISA). CCHFV seropositivity was recorded in 255 out of 269 camels accounting for a prevalence rate of 94.8% (95%CI = 92.14-97.45). The seroprevalence by origin was determined to be 97% (193/199) in imported camels and 86% (49/57) in local ones (p > 0.25). Tick presence (OR = 12.35, 95%CI = 1.41-107.43, p < 0.05) was recorded as the only potential risk factor for contracting CCHFV. This study shows for the first time that camels are exposed to CCHFV in Algeria with a significantly high seroprevalence. It also underlines the need for further research to investigate the broader extent of circulating CCHFV in the country, whether in humans, animals, or ticks.


Asunto(s)
Anticuerpos Antivirales , Camelus , Ensayo de Inmunoadsorción Enzimática , Virus de la Fiebre Hemorrágica de Crimea-Congo , Fiebre Hemorrágica de Crimea , Animales , Camelus/virología , Argelia/epidemiología , Fiebre Hemorrágica de Crimea/epidemiología , Fiebre Hemorrágica de Crimea/veterinaria , Fiebre Hemorrágica de Crimea/virología , Estudios Seroepidemiológicos , Virus de la Fiebre Hemorrágica de Crimea-Congo/inmunología , Virus de la Fiebre Hemorrágica de Crimea-Congo/aislamiento & purificación , Masculino , Femenino , Factores de Riesgo , Anticuerpos Antivirales/sangre , Ensayo de Inmunoadsorción Enzimática/veterinaria , Prevalencia , Enfermedades por Picaduras de Garrapatas/epidemiología , Enfermedades por Picaduras de Garrapatas/veterinaria , Enfermedades por Picaduras de Garrapatas/virología , Inmunoglobulina G/sangre , Garrapatas/virología
12.
Artículo en Inglés | MEDLINE | ID: mdl-39264068

RESUMEN

OBJECTIVE: The purpose of the present study was to assess the benefits of simulation for advancing knowledge and assisting healthcare staff in optimization of procedures when managing severe pre-eclampsia/eclampsia (sPE/E). METHODS: A randomized educational trial was conducted with two groups: Group I received theoretical training, while group II received the same training along with simulation scenarios based on the management of sPE/E. The study involved 199 healthcare providers, including physicians, midwives, skilled birth attendants, and nurses. The study analyzed the percentage of correct answers on both the multiple-choice questions (MCQ) and the objective structured clinical examinations (OSCE) to evaluate theoretical knowledge and clinical skills objectively. RESULTS: Statistically significant differences were found immediately after training between groups I and II, whose mean percentages were 65.0% (±11.2) versus 71.0% (±9.8) (P < 0.001). A statistically significant reduction in the percentage of correct answers was found in both groups and demonstrated a discrepancy between immediate post-training test and post-training test at 3 months scores of 11.6% (±1.3) in group I versus 7.2% (±0.6) in group II. OSCE1 and OSCE2 scores were significantly higher in group II than in group I (P < 0.001). CONCLUSION: Simulation combined with theoretical training would appear to be an interesting method of training for advancing knowledge and improving skills of healthcare providers in their management of sPE/E. Our goal is for this method to be used to reduce real-life maternal mortality in the South Kivu region of the Democratic Republic of Congo.

13.
Front Epidemiol ; 4: 1310071, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39238565

RESUMEN

The natural foci of Crimean-Congo haemorrhagic fever (CCHF) in Kazakhstan are geographically located in the southern regions of the country (Kyzylorda, Turkestan and Zhambyl regions), where the infection of ticks with the CCHF virus predominantly reside, tick species composition and the number of vectors are monitored annually. The objective of our research was to investigate the genetic variants of the CCHF virus in the southern endemic regions, as well as to monitor the spread of the CCHF virus in the western regions of the country (Aktobe, Atyrau and Mangystau regions). In total, 974 (216 pools) ticks from the western regions and 3527 (583 pools) ticks from the southern regions collected during 2021-2022 were investigated. The presence of CCHF virus was detected by real-time reverse transcription PCR (qRT- PCR) in 1 pool out of 799 pools (0.12%) with Hyalomma scupense ticks captured in the CCHF-endemic Kyzylorda region. In the western regions, CCHF virus was not detected in ticks. The sequencing of incomplete fragments of the S, M and L segments of the CCHF virus in the detected virus was identified as genotype Asia - I. Phylogenetic analysis showed that the isolate obtained in this study is grouped with the isolate from a patient with CCHF, which we reported in 2015 (KX129738 Genbank). Our findings highlight the importance of including sequencing in the annual monitoring system for better understanding the evolution of the CCHF virus in the study areas of our country.

14.
3 Biotech ; 14(3): 73, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-39262831

RESUMEN

This study is the first report on purification, characterization, and application of laccase derived from the white-rot fungus, Pleurotus ostreatus HK35 (Hungary strain), in Congo Red decolorization. The purification process involved ammonium sulfate precipitation, dialysis, anion exchange chromatography, and ultrafiltration, yielding a specific laccase activity of 15.26 U/mg and a 30.21% recovery rate. The purified enzyme, with a molecular weight of approximately 34 kilodaltons, displayed optimal activity at a temperature of 60 °C and pH 4.0 when using 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) as a substrate. The enzyme maintained over 82.02 ± 1.01% of its activity at temperatures up to 50 °C after 180 min but displayed less than 5% of its activity at 60 and 70 °C. Notably, the enzyme's activity was significantly enhanced by Pb(NO3)2, whereas ß-mercaptoethanol completely inhibited the activity. Utilizing the Box-Behnken design, we optimized Congo Red decolorization efficiency to 91.05 ± 0.82% at 100 mg/L Congo Red, 1.5 mM mediator concentration, and 1.6 U/mL laccase activity. Analysis of Variance (ANOVA) suggested the model was significant, and all variables significantly influenced decolorization efficiency. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-024-03926-7.

15.
Environ Sci Pollut Res Int ; 31(39): 51415-51430, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39112896

RESUMEN

This study focuses on developing copper oxide-based nanocomposites using plant extracts for photocatalytic applications. Curcuma amada leaf and Alysicarpus vaginalis leaf extracts were utilized alongside recycled copper precursors to synthesize photocatalysts via a green synthesis approach. Structural characterization through X-ray diffraction confirmed the formation of monoclinic CuO with reduced crystallite sizes due to plant extract incorporation. Fourier-transform infrared spectroscopy identified additional functional groups from the plant extracts, enhancing the material's properties. UV-Vis spectroscopy demonstrated increased light absorption and narrowed bandgaps in the nanocomposites, crucial for efficient photocatalysis under visible light. Morphological studies using FESEM revealed unique leaf-like structures in nanocomposites, indicative of the plant extract's influence on morphology. Photocatalytic degradation of methylene blue, rhodamine B, Congo red, and reactive blue 171 dyes showed enhanced performance of plant extract-modified CuO compared to without plant extract mediated CuO, attributed to improved charge carrier separation and extended lifetime. The effects of pH, catalyst dosage, and dye concentration on degradation efficiency were systematically investigated, highlighting optimal conditions for each dye type. Radical scavenger studies confirmed the roles of holes and hydroxyl radicals in the degradation process. Kinetic analysis revealed pseudo-second-order kinetics for dye degradation, underscoring the effectiveness of the nanocomposites. Overall, this research provides insights into sustainable photocatalytic materials using plant extracts and recycled copper, showcasing their potential for environmental remediation applications.


Asunto(s)
Cobre , Nanocompuestos , Extractos Vegetales , Nanocompuestos/química , Cobre/química , Extractos Vegetales/química , Catálisis , Azul de Metileno/química
16.
Environ Monit Assess ; 196(9): 801, 2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39120831

RESUMEN

This study presents the first data on levels of natural radioactive elements in sediments from coastal ecosystems of the Republic of Congo. Sediment samples from five coastal sites were collected and analyzed by high-resolution gamma spectrometry for determination of activities of long-lived gamma-emitting radionuclides (234Th, 238U, 226Ra, 210Pb, 228Th, 228Ra, and 40 K). The specific activities were of the same order of magnitude as those measured in sediments of most countries neighboring the Republic of Congo. However, variations in activities were observed from one site to another and also from one sampling point to another within the same site without exceeding the global average reference values. It can be assumed, therefore, that no significant anthropogenic impact is perceptible in the study area. The most commonly used radiological hazard parameters, based mainly on 238U, 232Th, and 40 K activities, were assessed and the ERICA tool was applied to quantify the radiation exposure burden to human and biota resulting from radionuclides in sediments. Besides being useful for future monitoring efforts, the data produced in this work could be important for the worldwide database on radioactivity in the oceans and seas (MARIS) since no data are available in the Congolese marine environment.


Asunto(s)
Ecosistema , Sedimentos Geológicos , Monitoreo de Radiación , Sedimentos Geológicos/química , Congo , Medición de Riesgo , Contaminantes Radiactivos del Agua/análisis , Torio/análisis , Uranio/análisis , Radio (Elemento)/análisis , Humanos
17.
Int J Biol Macromol ; 277(Pt 4): 134353, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39089559

RESUMEN

The work was aimed at evaluating the adsorptive properties of waste newspaper (WN) activated carbons chemically produced using sodium salts for methylene blue (MB) and congo red (CR) removal. The activated carbons, designated as AC1, AC2, AC3 and AC4 were prepared through impregnation with NaH2PO4, Na2CO3, NaCl and NaOH, respectively and activation at 500 °C for 1 h. The activated carbons were characterized for surface chemistry, thermal stability, specific area, morphology and composition. The AC1 with a surface area of 917 m2/g exhibits a greater MB capacity of 651 mg/g. Meanwhile, a greater CR capacity was recorded by AC2 at 299 mg/g. The pseudo-second order model fitted well with the kinetic data, while the equilibrium data could be described by Langmuir model. The thermodynamic parameters, i.e.., positive ΔH°, negative ΔG° and positive ΔS° suggest that the adsorption of dyes is endothermic, spontaneous and feasible at high solution temperature. To conclude, WN is a potential cellulose source for producing activated carbon, while NaH2PO4 activation could be employed to convert WN into activated carbon for effective dye wastewater treatment.


Asunto(s)
Celulosa , Carbón Orgánico , Rojo Congo , Azul de Metileno , Azul de Metileno/química , Celulosa/química , Rojo Congo/química , Adsorción , Carbón Orgánico/química , Cinética , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación , Papel , Purificación del Agua/métodos , Termodinámica , Sales (Química)/química , Temperatura
18.
Biofilm ; 8: 100214, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39184815

RESUMEN

Biofilm growth facilitates the interaction of uropathogenic Escherichia coli (UPEC) with the host environment. The extracellular polymeric substances (EPS) of UPEC biofilms are composed prominently of curli amyloid fiber and cellulose polysaccharide. When the organism is propagated as a colony biofilm on agar media, these macromolecules can generate pronounced macroscopic structures. Moreover, curli/cellulose associate tightly with Congo red, generating a characteristic pink-to-red staining pattern when the media is supplemented with this dye. Among different clinical isolates of UPEC, changes in the abundance of curli/cellulose can lead to diverse colony biofilm phenotypes on a strain-by-strain basis. Nevertheless, for any given isolate, these phenotypes are classically homogenous throughout the colony biofilm. Here, we report that a subset of clinical UPEC isolates display heterogenous 'peppermint' colony biofilms, with distinct pale and red subpopulations. Through isolation of these subpopulations and whole genome sequencing, we demonstrate various emergent mutations associated with the phenomenon, including within the gene encoding the outer membrane lipoprotein nlpI. Deletion of nlpI within independent strain-backgrounds increased biofilm rugosity, while its overexpression induced the peppermint phenotype. Upregulation of EPS-associated proteins and transcripts was likewise observed in the absence of nlpI. Overall, these results demonstrate that EPS elaboration in UPEC is impacted by nlpI. More broadly, this phenomenon of intra-strain colony biofilm heterogeneity may be leveraged as a tool to identify additional members within the broad collection of genes that regulate or otherwise affect biofilm formation.

19.
Int J Biol Macromol ; 279(Pt 1): 134879, 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39168198

RESUMEN

This context summarizes a detail on the fabrication of Acacia senegal Gum Hydrogel (ASGh) within well-engineered microemulsion, and thereafter chemical modification for environmental remediation. In brief, Divinylsulfone was used to crosslink polymeric chains and produce ASGh in ˂50 µm size within the reverse-microemulsion of Natrium-bis-(2-ethylhexyl) sulfosuccinate in gasoline. ASGh were subjected to chemical modification via versatile diethylenetriamine to produce m-[ASGh] for adsorptive removal of methyl orange (MO), eosin Y (EY) and congo red (CR) from waste-water. ASGh and m-[ASGh] were characterized through Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and zeta potential measurements. For instance, FT-IR spectra depicted new bands upon Diethylenetriamine modification. The zeta potential measurements confirm a positively charged surface of m-[ASGh] upon Diethylenetriamine addition. Interestingly, 0.05 g m-[ASGh] demonstrated 91.0, 84.1, and 73.0 % removal efficiency towards MO, EY and CR, respectively in 2 h equilibrium time. Langmuir, Freundlich and modified-Freundlich isotherms were applied to further delineate adsorption data. Modified-Freundlich model depicted comparatively more agreeable fit, and delivered R2 value nearer to unity. Further, 143 mg·g-1, 130 mg·g-1 and, 116 mg·g-1 maximum adsorption capacity (QM) was represented by m-[ASGh] towards MO, EY and CR, respectively in 2 h. Interestingly, real water sample were tested whereby, the QM against MO, EY and CR was 146 mg·g-1, 132 mg·g-1 and, 111 mg·g-1, respectively in 2 h equilibrium time. To conclude, m-[ASGh] could be treated as decolorizing agent in real waste-water polluted through negatively charged organic pollutants, particularly MO.

20.
Interface Focus ; 14(4): 20230079, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39129855

RESUMEN

In this article, we examine the scientific and sustainable research capacity outcomes of the 'Congo River: user Hydraulics and Morphology' or CRuHM project, a six-year effort supported by the Royal Society's Africa Capacity Building Initiative. This project brought together a consortium of African and UK universities to undertake the first large-scale scientific expeditions to the Congo basin of the modern era in order to better understand the hydraulics and geomorphology of this understudied but globally important river. The river is essential for navigation, irrigation, drinking water and hydroelectric power generation for the 10 basin countries and is critically important for biodiversity and global nutrient, carbon and climatological cycles. This article summarizes the new scientific understanding contributed by the project and the steps taken to ensure a meaningful legacy that would continue long beyond the finite lifetime of available funding. Actions taken to achieve this include establishing a new hydrology research centre at the University of Kinshasa as well as steps to build a wider international community of Congo basin researchers. In this way, we hope to build momentum for future funding initiatives and collaboration.

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