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1.
Muscle Nerve ; 70(5): 1095-1098, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39136364

RESUMO

INTRODUCTION/AIMS: Following the approval of risdiplam, there are more possibilities for disease-modifying therapy (DMT) in children with spinal muscular atrophy (SMA). Non-treatment-naïve subjects with SMA involved in the JEWELFISH study, designed to evaluate the safety and tolerability of risdiplam, were required to undergo a washout period before receiving risdiplam. This study aims to investigate the safety of administering risdiplam in patients within 90 days of receiving treatment with nusinersen. METHODS: Data were collected on SMA patients who had undergone treatment with nusinersen, and who then received risdiplam within 90 days of their last dose of nusinersen, including demographic characteristics, information on treatment with nusinersen and risdiplam, adverse events, and laboratory assessments in a follow-up period of 90 days, presented as median (range). RESULTS: A total of 15 children with SMA were reported, including 8 males and 7 females. The median number of doses of previous nusinersen treatment received was 8 (6-17) doses, and the median age at first risdiplam treatment was 4.3 (1.9-11.2) years. Specifically, 8 children received risdiplam 30 days or less after their most recent nusinersen treatment, 2 at 31-60 days after nusinersen, and 5 at 61-89 days post-nusinersen. Adverse events of pyrexia, pneumonia, vomiting and rash were reported in 4 patients. DISCUSSION: Our study showed good safety data on patients who received risdiplam following nusinersen within the washout period of 90 days. This supplements the JEWELFISH study in the era of DMT, providing additional guidance for clinicians, but additional data from other centers is needed.


Assuntos
Atrofia Muscular Espinal , Oligonucleotídeos , Humanos , Masculino , Feminino , Oligonucleotídeos/uso terapêutico , Oligonucleotídeos/efeitos adversos , Oligonucleotídeos/administração & dosagem , Pré-Escolar , Atrofia Muscular Espinal/tratamento farmacológico , Lactente , Criança , Resultado do Tratamento , Compostos Azo , Pirimidinas
2.
Ital J Pediatr ; 50(1): 157, 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39183350

RESUMO

BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal recessive motor neuron disease that leads to multiple organ dysfunction. The advent of disease-modifying treatments makes the early diagnosis of SMA critical. Health information literacy is vital for obtaining, understanding, screening, and using health information. Considering the importance of early diagnosis and the challenges in obtaining accurate information on patients with SMA, this cross-sectional study assessed health information literacy among children with SMA and their caregivers in China. METHODS: Interviews with the caregivers of 10 patients with SMA were conducted by neurologists specializing in SMA. A questionnaire for evaluating the level of health information literacy was further developed among 145 children with SMA aged 10.0-120.0 months, with the average age of 81.9 months, and their caregivers. Parameters, such as the age at the onset of the first symptom and time from recognition of the first symptom to diagnosis, were examined. Health information literacy was measured using four dimensions: cognition, search, evaluation, and application. RESULTS: The average time from the first symptom to first medical consultation was 4.8 months, and that from the first symptom to diagnosis was 10.8 months. There is a significant delay from the onset of the initial symptoms to a definitive diagnosis. Thirty-five (24%) patients had poor while 26 (18%) had high health information literacy. The overall score for health information literacy was 69; the scores for health information cognition and application were 90 and 84, respectively. The scores for evaluation (61) and search (57) were low. Medical personnel were considered the most professional and credible sources of information. Additionally, search engines and patient organizations were the other two most important sources of health literacy. CONCLUSION: Patients with SMA and their caregivers had low levels of health information literacy. SMA information visibility and standardization need to be improved. Medical personnel with experience in the diagnosis and treatment of SMA and media should aim to share knowledge and increase the quality of life of those with SMA.


Assuntos
Cuidadores , Letramento em Saúde , Humanos , Masculino , Feminino , Estudos Transversais , Criança , Pré-Escolar , Lactente , China , Atrofia Muscular Espinal/diagnóstico , Atrofia Muscular Espinal/terapia , Inquéritos e Questionários
3.
Clin Chem Lab Med ; 62(12): 2405-2414, 2024 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-38860968

RESUMO

OBJECTIVES: Spinal muscular atrophy (SMA) is a neuromuscular disorder caused by homozygous deletion and compound heterozygous mutations in survival motor neuron 1 (SMN1), with severity tied to the copy number of survival motor neuron 2 (SMN2). This study aimed to develop a rapid and comprehensive method for the diagnosis of SMA. METHODS: A total of 292 children with clinically suspected SMA and 394 family members were detected by the amplification refractory mutation system polymerase chain reaction-capillary electrophoresis (ARMS-PCR-CE) method, which targeted 19 reported mutations, and the results were compared with those in multiplex ligation-dependent probe amplification (MLPA). Individuals with identified point mutations were further confirmed by SMN1 long-range PCR and Sanger sequencing. RESULTS: A total of 202 children with SMA, 272 carriers, and 212 normal individuals were identified in this study. No difference was found in the R-value distribution of exons 7 and 8 in SMN1 and SMN2 among these cohorts, with coefficients of variation consistently below 0.08. To detect exon 7 and 8 copy numbers in SMN1 and SMN2, the ARMS-PCR-CE results were concordant with those of MLPA. Approximately 4.95 % (10/202) of the study patients had compound heterozygous mutations. CONCLUSIONS: The ARMS-PCR-CE assay is a comprehensive, rapid, and accurate diagnostic method for SMA that simultaneously detects copy numbers of exons 7 and 8 in SMN1/SMN2, as well as 19 point mutations in SMN1 and 2 enhancers in SMN2. This approach can effectively reduce the time frame for diagnosis, facilitating early intervention and preventing birth defects.


Assuntos
Eletroforese Capilar , Atrofia Muscular Espinal , Mutação , Reação em Cadeia da Polimerase , Proteína 1 de Sobrevivência do Neurônio Motor , Proteína 2 de Sobrevivência do Neurônio Motor , Humanos , Atrofia Muscular Espinal/genética , Atrofia Muscular Espinal/diagnóstico , Eletroforese Capilar/métodos , Proteína 1 de Sobrevivência do Neurônio Motor/genética , Reação em Cadeia da Polimerase/métodos , Proteína 2 de Sobrevivência do Neurônio Motor/genética , Criança , Feminino , Masculino , Pré-Escolar , Éxons/genética , Lactente
6.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 52(6): 714-720, 2023 Dec 17.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38105669

RESUMO

OBJECTIVES: To investigate the clinical efficacy and safety of salbutamol in the treatment of children with later-onset spinal muscular atrophy (SMA). METHODS: This study is a prospective single-arm phase Ⅲ clinical study. Pediatric patients with SMA type Ⅱ and Ⅲ who visited Department of Neurology, Children's Hospital, Zhejiang University School of Medicine from December 2020 to June 2022 were enrolled. All patients were evaluated with motor function scales, pulmonary function test and drug safety before study. Patients were treated with salbutamol tablets orally, with an initial dose of 1 mg (tid). If tolerable, the dose was increased to 1.5 mg (tid) in the second week, then increased to 2 mg (tid) from the third week and maintained for 6 months. Patients were followed up at 1, 3 and 6 months of treatment. RESULTS: Twenty-six patients were enrolled, including 10 boys and 16 girls. There were 16 cases of SMA type Ⅱ and 10 cases of type Ⅲ with age at treatment initiation of 5.67 (3.13, 7.02) years and disease duration of 2.54 (1.31, 4.71) years. The Hammersmith Functional Motor Scale-Expanded (HFMSE) scores were increased from 14.0 (6.5, 43.0) before treatment to 26.0 (15.0, 46.5) after treatment (Z=-4.144, P<0.01) in 25 cases. The Revised Upper Limb Module Scale scores were increased from 33.0 (25.5, 36.0) before treatment to 35.0 (31.0, 36.5) after treatment (Z=-2.214, P<0.05) in 9 cases. In 7 ambulant children with SMA type Ⅲ, the six minutes walking distance was increased by 30 (15, 52) m after a 6-month treatment (Z=-2.366, P<0.05). Compared with the baseline pulmonary functions the patients showed a significant increase in forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and peak expiratory flow (PEF) in 15 cases after treatment (all P<0.05). According to patients and caregivers subjective reporting, there were various degrees of improvement in coughing, sputum production ability and exercise endurance. No serious adverse events were observed during the study. CONCLUSIONS: Short-term oral administration of salbutamol may improve motor and pulmonary functions in later-onset SMA children with good safety.


Assuntos
Atrofia Muscular Espinal , Atrofias Musculares Espinais da Infância , Masculino , Feminino , Humanos , Criança , Albuterol/uso terapêutico , Estudos Prospectivos , Atrofia Muscular Espinal/tratamento farmacológico , Atrofias Musculares Espinais da Infância/tratamento farmacológico , Resultado do Tratamento
7.
Eur J Paediatr Neurol ; 46: 55-60, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37453233

RESUMO

AIM: This retro-prospective observational study described the experience in lumbar puncture procedures in children with spinal muscular atrophy (SMA) with and without neuromuscular scoliosis in a single center. The technical feasibility of intrathecal nusinersen administration was the main limiting factor. STUDY DESIGN: A total of 457 technically successful intrathecal injections based on a hierarchical strategy in Cobb angle were reviewed in 81 SMA children aged 0.75-13.5 years who were referred for nusinersen injections in our hospital from October 2019 to December 2022. RESULTS: Under local anesthesia, conventional lumbar puncture was performed on 47 patients without spinal deformity (Cobb angle of 0-10°) and 20 patients with moderate scoliosis (Cobb angle of 10-50°). Ultrasound-assisted lumbar puncture was performed on 12 patients with moderate scoliosis but lordosis. A combination of ultrasound imaging and three-dimensional CT under sedation was performed in the remaining 14 patients with severe scoliosis (Cobb angle >50°). No severe complications were found. CONCLUSION: Cobb angle is an important basis for intrathecal administration of nusinersen. It is feasible and suitable to carry out intrathecal nusinersen injection under ultrasound combined with three-dimensional CT imaging for children with severe scoliosis.

8.
Neurol Ther ; 12(3): 961-976, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37103747

RESUMO

INTRODUCTION: Spinal muscular atrophy (SMA) can cause multiple system dysfunction, especially lipid metabolic disorders, for which management strategies are currently lacking. Microbes are related to metabolism and the pathogenesis of neurological diseases. This study aimed to preliminarily explore the alterations in the gut microbiota in SMA and the potential relationship between altered microbiota and lipid metabolic disorders. METHODS: Fifteen patients with SMA and 17 gender- and age-matched healthy controls were enrolled in the study. Feces and fasting plasma samples were collected. 16S ribosomal RNA sequencing and nontargeted metabolomics analysis were performed to explore the correlation between microbiota and differential lipid metabolites. RESULTS: No significant difference was found in microbial diversity (α- and ß-diversity) between the SMA and control groups, with both groups having a relatively similar community structure. However, compared to the control group, the SMA group showed an increased relative abundance of the genera Ruminiclostridium, Gordonibacter, Enorma, Lawsonella, Frisingicoccus, and Anaerofilum and a decreased abundance of the genera Catabacter, Howardella, Marine_Methylotrophic_Group_3, and Lachnospiraceae_AC2044_group. The concurrent metabolomic analysis showed that the SMA group had 56 different kinds of lipid metabolite levels than did the control group. Additionally, the Spearman correlation suggested a correlation between the altered differential lipid metabolites and the above-mentioned altered microbiota. CONCLUSIONS: The gut microbiome and lipid metabolites differed between the patients with SMA and the control subjects. The altered microbiota may be related with the lipid metabolic disorders in SMA. However, further study is necessary to clarify the mechanism of lipid metabolic disorders and develop management strategies to improve the related complications in SMA.

9.
Front Neurol ; 13: 1034894, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36468044

RESUMO

Background: Body composition analysis is a valuable tool for assessing and monitoring the nutritional status of children with spinal muscular atrophy (SMA). This study was designed to compare the consistency of bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA), as the gold standard method for assessing body composition in clinical practice when treating children with type II and III SMA. Methods: From 2019 to 2021, we performed a retrospective analysis of body composition by DXA and BIA measurement methods in patients with type II and III SMA treated at a Chinese tertiary children's hospital. Fat mass (FM), muscle mass (MM), bone mineral content (BMC), and visceral fat area (VFA) were compared using paired sample t-tests. We calculated Lin's concordance correlation coefficient (CCC) and Spearman correlation coefficient to verify the correlation between DXA and BIA measurements. Bland-Altman analysis was used to assess the consistency of the two methods. Results: Fifty-seven children with type II and III SMA were recruited. Compared with body composition measured by DXA, the average FM measured by BIA is significantly lower (P <0.001), whereas the average MM, BMC, and VFA measured by BIA are significantly higher (P < 0.001) in children with SMA. Overall, the difference between MM (Delta [BIA-DAX] = 1.6 kg) and FM (Delta [BIA-DAX] = -1.6 kg) measured by DXA and BIA was minor, whereas the difference of VFA (Delta [BIA-DAX] = -43.5 cm) was significantly large. Correlation analysis indicated a substantial correlation of MM (CCC = 0.96 [95% confidence interval (CI) = 0.93-0.98], r = 0.967 [P < 0.0001]) and FM (CCC = 0.95 [95% CI = 0.92-0.97], r = 0.953 [P < 0.0001]), and poor correlation of BMC (CCC = 0.61 [95% CI = 0.42-0.75], r = 0.612 [P < 0.0001]) and VFA (CCC = 0.54 [95% CI = 0.33-0.70], r = 0.689 [P < 0.0001]) measurements between the two methods. The Bland-Altman analysis suggests that the majority of participants were within LOA. In addition, differences in MM and VFA measurements between BIA and DAX increased according to patients' increasing height, whereas differences in FM and BMC did not differ with height. Conclusion: BIA overestimates MM and underestimates the FM, BMC, and VFA in children with SMA compared with DXA measurements. Overall, the non-invasive, easy-to-use, and repeatable BIA measurements were found to be in good agreement with DXA measurements, especially for FM and MM, which are essential parameters for the nutritional evaluation of children with SMA.

11.
Front Nutr ; 9: 960006, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36046135

RESUMO

Background and aims: Children with spinal muscular atrophy (SMA) have a high rate of dyslipidaemia, which is a risk factor of vital importance for cardiovascular diseases in adulthood. Studies have demonstrated that the serum zinc level is associated with lipid profiles in the general population as well as in individuals diagnosed with obesity or diabetes. The purpose of this study was to evaluate the relationship between serum zinc level and lipid profiles in children with SMA. Methods: This cross-sectional study was launched in a tertiary children's medical center in China and involved pediatric patients with SMA under the management of a multidisciplinary team of outpatient services from July 2019 to July 2021. Anthropometric information, general clinical data, serum zinc level, lipid profiles, and body composition data were collected. Multivariate analysis was used for a thorough inquiry on the association between the serum zinc level and lipid profiles. Results: Among the 112 patients with SMA [median (IQR) age 5.54 years (2.75-8.29), 58.04% female], who fulfilled the inclusion criteria of the study, dyslipidaemia was detected in 60 patients (53.57%). Based on multivariable linear regression, serum zinc level was positively associated with high-density lipoprotein cholesterol (HDL-C; ß = 1.63, 95% CI = 0.44-3.22) and apolipoprotein A1 (APO A1; ß = 2.94, 95% CI = 0.03-5.85) levels, independently of age, sex, type, activity, percentage of body fat, and body mass index. As the serum zinc level increased by 10 µmol/L, the risk of low APO A1 levels decreased by 35% (OR = 0.65, 95% CI = 0.44-0.97) according to multivariable logistic regression analyses. Conclusion: Serum zinc concentration was positively correlated with HDL-C and APO A1 levels among children with SMA. We suggest measures to correct the lower level of serum zinc to improve HDL-C and APO A1 levels.

12.
Front Cell Neurosci ; 16: 953620, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36060274

RESUMO

Background: Patients with spinal muscular atrophy (SMA) may suffer from multisystem injury, including an impaired cardiovascular system. However, M-mode echocardiography, the current dominant echocardiographic modality, is limited in the detection of myocardial injury. We considered the use of left ventricular strain imaging in detecting myocardial injury and explored the serum lipid profile related to cardiovascular disease in later-onset SMA children. Methods: A case-control study involving 80 patients with later-onset SMA and 80 age-, gender-, and body surface area-matched control children was conducted in a single tertiary pediatric hospital in China. Data on the left ventricular strain measured using two-dimensional speckle tracking echocardiography, left ventricular function parameters assessed by M-mode echocardiography, and serum lipid profile of these two groups were retrospectively collected for differential analysis. Results: The mean age of the 80 SMA patients were (6.87 ± 2.87) years, of which 46 were type 2 and 34 were type 3 patients. The global longitudinal strain (GLS) of the SMA group (-18.7 ± 2.9%, p < 0.001) was lower than that of the control group; the time to peak longitudinal strain (TTPLS) of the SMA group (22.9 ± 13.6 ms, p < 0.001) was higher than that of the control group, while left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS), measured by the Teichholz method of M-mode echocardiography, showed no significant differences between the two groups. In addition, independent indicators for cardiovascular risk, including total cholesterol (TC)/HDL, low-density lipoprotein (LDL)/HDL, and Apo B/Apo A1 levels, were higher in SMA children than in the control group. Conclusion: Compared with healthy controls, later-onset SMA children presented with reduced GLS and prolonged TTPLS while the LVEF and LVFS values were within normal range. In particular, whether a reduced GLS or prolonged TTPLS in later-onset SMA compared to the control group can predict the risk of future cardiomyopathy remains to be investigated.

14.
ACS Nano ; 16(6): 9297-9303, 2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35713188

RESUMO

Light can possess orbital angular momentum (OAM), in addition to spin angular momentum (SAM), which offers nearly infinite possible values of momentum states, allowing a wider degree of freedom for information processing and communications. The OAM of light induces a selection rule that obeys the law of conservation of angular momentum as it interacts with a material, affecting the material's optical and electrical properties. In this work, silicon nanowire field-effect transistors are subjected to light with OAM, also known as twisted light. Electrical measurements on the devices consequently reveal photocurrent enhancements after incrementing the OAM of the incident light from 0ℏ (fundamental mode) to 5ℏ. Such a phenomenon is attributed to the enhancements of the photogating and the photoconductive effects under the influence of the OAM of light, the underlying mechanism of which is proposed and discussed using energy band diagrams. With these observations, a strategy for controlling photocurrent has been introduced, which can be a realization of the application in the field of optoelectronics technology.

15.
Orphanet J Rare Dis ; 16(1): 385, 2021 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-34503559

RESUMO

BACKGROUND: Spinal muscular atrophy (SMA) is a rare neurogenetic disease which involves multisystem dysfunctions such as respiratory, digestive, and motor disorders. Anxiety, depression and other psychological disorders often accompany severe chronic physical diseases. The aim of this study was to investigate the prevalence of anxiety and depression along with their influencing factors among school-age patients with SMA. METHODS: We conducted a cross-sectional study on school-age SMA patients in China. Patients aged 8-18 years with a genetic diagnosis of 5qSMA were invited to answer a questionnaire composed of sociodemographic and clinical questions, then to complete the Screen for Child Anxiety-Related Emotional Disorders and Depression Self-Rating Scale for depression and anxiety level evaluation. At the end of the questionnaire, further questions assessed the subjective anxiety and subjective depression of patients' caregivers and their expectations for their child's future. RESULTS: Complete data were available for 155 patients. The sample included 45.8% boys and 54.2% girls; 65.2% were type II, 27.1% were type III, and the remainder were type I SMA. Rates of anxiety and depression in these school-age SMA patients were 40.0% and 25.2%, respectively. Gender, age, and disease type were not associated with anxiety or depression, but respiratory system dysfunction, digestive system dysfunction, skeletal deformity, rehabilitation exercise, academic delay, specialized support from school, household income level, caregivers' subjective anxiety, and caregivers' expectations were significantly related to both anxiety and depression. CONCLUSIONS: There was a high prevalence of anxiety and depression in school-age SMA patients in China. Professional psychological care maybe included in the standard of care. These results also call for possible targets for intervention such as reducing complications, improving drug accessibility, retaining normal schooling, strengthening school support, and enhancing the ability of the caregivers of SMA patients to assist in the diagnosis and treatment of the disease, so improving the mental health of SMA patients.


Assuntos
Ansiedade , Atrofia Muscular Espinal , Ansiedade/epidemiologia , Cuidadores , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Atrofia Muscular Espinal/epidemiologia , Instituições Acadêmicas
16.
ACS Nano ; 15(9): 14822-14829, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34436860

RESUMO

Twisted light carries a defined orbital angular momentum (OAM) that can enhance forbidden transitions in atoms and even semiconductors. Such attributes can possibly lead to enhancements of the material's photogenerated carriers through improved absorption of incident light photons. The interaction of twisted light and photovoltaic material is, thus, worth studying as more efficient photovoltaic cells are essential these days due to the need for reliable and sustainable energy sources. Two-dimensional (2D) MoS2, with its favorable optoelectronic properties, is a good platform to investigate the effects of twisted light on the photon absorption efficiency of the interacting material. This work, therefore, used twisted light as the exciting light source onto a MoS2 photovoltaic device. We observed that while incrementing the incident light's quantized OAM at fixed optical power, there are apparent improvements in the device's open-circuit voltage (VOC) and short-circuit current (ISC), implying enhancements of the photoresponse. We attribute these enhancements to the OAM of light that has facilitated improved optical absorption efficiency in MoS2. This study proposes a way of unlocking the potentials of 2D-MoS2 and envisions the employment of light's OAM for future energy device applications.

18.
Front Genet ; 12: 605611, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33777091

RESUMO

Spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD) are two common kinds of neuromuscular disorders sharing various similarities in clinical manifestations. SMA is an autosomal recessive genetic disorder that results from biallelic mutations of the survival motor neuron 1 gene (SMN1; OMIM 600354) on the 5q13 chromosome. DMD is an X-linked disorder caused by defects in the DMD gene (OMIM 300377) on the X chromosome. Here, for the first time, we report a case from a Chinese family who present with clinical manifestations of both two diseases, including poor motor development and progressive muscle weakness. We identified a homozygous deletion in exons 7 and 8 of the SMN1 gene and a deletion in exon 50 of the DMD gene by whole-exome sequencing (WES) and multiplex ligation-dependent probe amplification (MLPA). This case expands our understanding of diagnosis for synchronous SMA and DMD and highlights the importance of various genetic testing methods, including WES, in differential diagnosis of neuromuscular diseases.

19.
Water Sci Technol ; 82(2): 373-385, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32941178

RESUMO

To evaluate the enhancing of the biological nitrogen removal effectiveness by electromagnetic wave loading on returned sludge in the A/A/O reactor, some experiments were completed with the returned sludge loaded by 2,450 MHz electromagnetic wave. The excess sludge yield and pollutant removal effect of the system were evaluated. Results showed that stronger denitrification effect and less sludge yield were achieved. When 30% of the returned sludge was loaded by electromagnetic wave, the actual denitrification efficiency increased by 7% without dosage. The dissolution of carbon, nitrogen and phosphorus from loaded returned sludge was detected, thus providing the system with a supplemental carbon source of 4.6 g/d SCOD. The specific oxygen uptake rate of the oxic activated sludge increased by 14%, and the denitrification rate of the anoxic activated sludge increased by 29%. Illumina MiSeq analysis showed that the microbial richness increased obviously, and denitrifying bacteria (i.e. Dechloromonas, Zoogloea and Azospira, etc.) were accumulated.


Assuntos
Nitrogênio , Esgotos , Anaerobiose , Reatores Biológicos , Desnitrificação , Radiação Eletromagnética , Fósforo , Eliminação de Resíduos Líquidos
20.
Environ Sci Pollut Res Int ; 27(3): 3413-3427, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31845252

RESUMO

Excess sludge was loaded by 2450 MHz electromagnetic wave in this study. The mechanism of electromagnetic wave loading on the releasing of bound water before sludge flocculation dewatering was investigated through observing the changes of extracellular polymeric substances (EPS) composition, surface charge, and particle size distribution. The results showed that the 8.55 g/g total suspended solids (TSS) of bound water was reduced with 160 J/mL electromagnetic wave, and the moisture content of sludge decreased by 3.02%. The EPS structure in the sludge floc matrix was destroyed and the LB-EPS content reduced. Simultaneously, infrared spectrum analysis indicated that bound water content was correlated both to the changes of hydrophilic and hydrophobic functional groups. Moreover, protein secondary structure analysis found that looser protein structure facilitated the exposure of internal hydrophobic groups and further promoted the sludge hydrophobic properties. Additionally, electromagnetic wave disintegrated colloidal stability through dipole motion. The zeta potential increased from - 25.57 to - 14.32 mV; the medium particle size (d0.5) decreased from 119.99 to 80.41 µm. More small molecules created in the supernatant were helpful to release bound water, which could further improve flocculation dewaterability of sludge with electromagnetic wave loading.


Assuntos
Esgotos , Eliminação de Resíduos Líquidos , Radiação Eletromagnética , Floculação , Tamanho da Partícula , Água
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