"Puberty age gap": new method of assessing pubertal timing and its association with mental health problems.

Puberty is linked to mental health problems during adolescence, and in particular, the timing of puberty is thought to be an important risk factor. This study developed a new measure of pubertal timing that was built upon multiple pubertal features and their nonlinear changes over time (i.e., with age), and investigated its association with mental health problems. Using the Adolescent Brain Cognitive Development (ABCD) cohort (N ~ 9900, aged 9-13 years), we employed three different models to assess pubertal timing. These models aimed to predict chronological age based on: (i) observed physical development, (ii) hormone levels (testosterone and dehydroepiandrosterone [DHEA]), and (iii) a combination of both physical development and hormones. To achieve this, we utilized a supervised machine learning approach, which allowed us to train the models using the available data and make age predictions based on the input pubertal features. The accuracy of these three models was evaluated, and their associations with mental health problems were examined. The new pubertal timing model performed better at capturing age variance compared to the more commonly used linear regression method. Further, the model based on physical features accounted for the most variance in mental health, such that earlier pubertal timing was associated with higher symptoms. This study demonstrates the utility of our new model of pubertal timing and suggests that, relative to hormonal measures, physical measures of pubertal maturation have a stronger association with mental health problems in early adolescence.

Connectomes for 40,000 UK Biobank participants: A multi-modal, multi-scale brain network resource.

We mapped functional and structural brain networks for more than 40,000 UK Biobank participants. Structural connectivity was estimated with tractography and diffusion MRI. Resting-state functional MRI was used to infer regional functional connectivity. We provide high-quality structural and functional connectomes for multiple parcellation granularities, several alternative measures of interregional connectivity, and a variety of common data pre-processing techniques, yielding more than one million connectomes in total and requiring more than 200,000 h of compute time. For a single subject, we provide 28 out-of-the-box versions of structural and functional brain networks, allowing users to select, e.g., the parcellation and connectivity measure that best suit their research goals. Furthermore, we provide code and intermediate data for the time-efficient reconstruction of more than 1000 different versions of a subject's connectome based on an array of methodological choices. All connectomes are available via the UK Biobank data-sharing platform and our connectome mapping pipelines are openly available. In this report, we describe our connectome resource in detail for users, outline key considerations in developing an efficient pipeline to map an unprecedented number of connectomes, and report on the quality control procedures that were completed to ensure connectome reliability and accuracy. We demonstrate that our structural and functional connectivity matrices meet a number of quality control checks and replicate previously established findings in network neuroscience. We envisage that our resource will enable new studies of the human connectome in health, disease, and aging at an unprecedented scale.

Tractography passes the test: Results from the diffusion-simulated connectivity (disco) challenge.

Estimating structural connectivity from diffusion-weighted magnetic resonance imaging is a challenging task, partly due to the presence of false-positive connections and the misestimation of connection weights. Building on previous efforts, the MICCAI-CDMRI Diffusion-Simulated Connectivity (DiSCo) challenge was carried out to evaluate state-of-the-art connectivity methods using novel large-scale numerical phantoms. The diffusion signal for the phantoms was obtained from Monte Carlo simulations. The results of the challenge suggest that methods selected by the 14 teams participating in the challenge can provide high correlations between estimated and ground-truth connectivity weights, in complex numerical environments. Additionally, the methods used by the participating teams were able to accurately identify the binary connectivity of the numerical dataset. However, specific false positive and false negative connections were consistently estimated across all methods. Although the challenge dataset doesn't capture the complexity of a real brain, it provided unique data with known macrostructure and microstructure ground-truth properties to facilitate the development of connectivity estimation methods.

Connectome spatial smoothing (CSS): Concepts, methods, and evaluation.

Structural connectomes are increasingly mapped at high spatial resolutions comprising many hundreds-if not thousands-of network nodes. However, high-resolution connectomes are particularly susceptible to image registration misalignment, tractography artifacts, and noise, all of which can lead to reductions in connectome accuracy and test-retest reliability. We investigate a network analogue of image smoothing to address these key challenges. Connectome Spatial Smoothing (CSS) involves jointly applying a carefully chosen smoothing kernel to the two endpoints of each tractography streamline, yielding a spatially smoothed connectivity matrix. We develop computationally efficient methods to perform CSS using a matrix congruence transformation and evaluate a range of different smoothing kernel choices on CSS performance. We find that smoothing substantially improves the identifiability, sensitivity, and test-retest reliability of high-resolution connectivity maps, though at a cost of increasing storage burden. For atlas-based connectomes (i.e. low-resolution connectivity maps), we show that CSS marginally improves the statistical power to detect associations between connectivity and cognitive performance, particularly for connectomes mapped using probabilistic tractography. CSS was also found to enable more reliable statistical inference compared to connectomes without any smoothing. We provide recommendations for optimal smoothing kernel parameters for connectomes mapped using both deterministic and probabilistic tractography. We conclude that spatial smoothing is particularly important for the reliability of high-resolution connectomes, but can also provide benefits at lower parcellation resolutions. We hope that our work enables computationally efficient integration of spatial smoothing into established structural connectome mapping pipelines.

Network communication models narrow the gap between the modular organization of structural and functional brain networks.

Structural and functional brain networks are modular. Canonical functional systems, such as the default mode network, are well-known modules of the human brain and have been implicated in a large number of cognitive, behavioral and clinical processes. However, modules delineated in structural brain networks inferred from tractography generally do not recapitulate canonical functional systems. Neuroimaging evidence suggests that functional connectivity between regions in the same systems is not always underpinned by anatomical connections. As such, direct structural connectivity alone would be insufficient to characterize the functional modular organization of the brain. Here, we demonstrate that augmenting structural brain networks with models of indirect (polysynaptic) communication unveils a modular network architecture that more closely resembles the brain's established functional systems. We find that diffusion models of polysynaptic connectivity, particularly communicability, narrow the gap between the modular organization of structural and functional brain networks by 20-60%, whereas routing models based on single efficient paths do not improve mesoscopic structure-function correspondence. This suggests that functional modules emerge from the constraints imposed by local network structure that facilitates diffusive neural communication. Our work establishes the importance of modeling polysynaptic communication to understand the structural basis of functional systems.

High-resolution connectomic fingerprints: Mapping neural identity and behavior.

Connectomes are typically mapped at low resolution based on a specific brain parcellation atlas. Here, we investigate high-resolution connectomes independent of any atlas, propose new methodologies to facilitate their mapping and demonstrate their utility in predicting behavior and identifying individuals. Using structural, functional and diffusion-weighted MRI acquired in 1000 healthy adults, we aimed to map the cortical correlates of identity and behavior at ultra-high spatial resolution. Using methods based on sparse matrix representations, we propose a computationally feasible high-resolution connectomic approach that improves neural fingerprinting and behavior prediction. Using this high-resolution approach, we find that the multimodal cortical gradients of individual uniqueness reside in the association cortices. Furthermore, our analyses identified a striking dichotomy between the facets of a person's neural identity that best predict their behavior and cognition, compared to those that best differentiate them from other individuals. Functional connectivity was one of the most accurate predictors of behavior, yet resided among the weakest differentiators of identity; whereas the converse was found for morphological properties, such as cortical curvature. This study provides new insights into the neural basis of personal identity and new tools to facilitate ultra-high-resolution connectomics.

Temporal complexity of fMRI is reproducible and correlates with higher order cognition.

It has been hypothesized that resting state networks (RSNs), extracted from resting state functional magnetic resonance imaging (rsfMRI), likely display unique temporal complexity fingerprints, quantified by their multiscale entropy patterns (McDonough and Nashiro, 2014). This is a hypothesis with a potential capacity for developing digital biomarkers of normal brain function, as well as pathological brain dysfunction. Nevertheless, a limitation of McDonough and Nashiro (2014) was that rsfMRI data from only 20 healthy individuals was used for the analysis. To validate this hypothesis in a larger cohort, we used rsfMRI datasets of 987 healthy young adults from the Human Connectome Project (HCP), aged 22-35, each with four 14.4-min rsfMRI recordings and parcellated into 379 brain regions. We quantified multiscale entropy of rsfMRI time series averaged at different cortical and sub-cortical regions. We performed effect-size analysis on the data in 8 RSNs. Given that the morphology of multiscale entropy is affected by the choice of its tolerance parameter (r) and embedding dimension (m), we repeated the analyses at multiple values of r and m including the values used in McDonough and Nashiro (2014). Our results reinforced high temporal complexity in the default mode and frontoparietal networks. Lowest temporal complexity was observed in the subcortical areas and limbic system. We investigated the effect of temporal resolution (determined by the repetition time TR) after downsampling of rsfMRI time series at two rates. At a low temporal resolution, we observed increased entropy and variance across datasets. Test-retest analysis showed that findings were likely reproducible across individuals over four rsfMRI runs, especially when the tolerance parameter r is equal to 0.5. The results confirmed that the relationship between functional brain connectivity strengths and rsfMRI temporal complexity changes over time scales. Finally, a non-random correlation was observed between temporal complexity of RSNs and fluid intelligence suggesting that complex dynamics of the human brain is an important attribute of high-level brain function.

Functional dedifferentiation of the brain during healthy aging.

Nonpathological aging is associated with significant cognitive deficits. Thus, the underlying neurobiology of aging-associated cognitive decline warrants investigation. In a recent study, Chong et al. (Chong JSX, Ng KK, Tandi J, Wang C, Poh J-H, Lo JC, Chee MWL, Zhou JH. J Neurosci 39: 5534-5550, 2019) provided insights into the association between cognitive decline and the loss of functional specialization in the brains of older adults. Here, we introduce the novel graph theoretical approach utilized and discuss the significance of their findings and broader implications on aging. We also provide alternate perspectives of their findings and suggest directions for future work.

Mineral features of connective dental hard tissues in hypoplastic amelogenesis imperfecta.

OBJECTIVE: To explore the mineral features of dentin and cementum in hypoplastic Amelogenesis imperfecta AI teeth. MATERIALS AND METHODS: Forty-four (44) teeth cleaned and free of caries were used: 20 control and 24 affected by hypoplastic amelogenesis imperfecta. Thirty-two teeth were studied by pQCT, cut in sections, and analyzed under microradiography, polarized light microscopy, and confocal Raman spectroscopy. Eight teeth were observed under scanning electron microscope. Four teeth were used for an X-ray diffraction. The mineral density data were analyzed statistically with the Mann-Whitney U test, using GraphPad InStat software. RESULTS: Both coronal dentin and radicular dentin were less mineralized in AI teeth when compared to control (respectively 6.2% and 6.8%; p < .001). Root dentinal walls were thin and irregular, while the cellular cementum layers were thick, reaching sometimes the cervical region of the tooth. Regular dentinal tubules and sclerotic dentin areas were noticed. Partially tubular or cellular dysplastic dentin and hyper-, normo-, or hypomineralized areas were noticed in the inter-radicular areas of hypoplastic AI teeth. The main mineral component was carbonate hydroxyapatite as explored by Raman spectroscopy and X-ray diffraction. CONCLUSIONS: Dentin and cementum in hypoplastic AI teeth are (i) hypomineralized, (ii) constituted of carbonate hydroxyapatite, and (iii) of non-homogenous structure.

ß-Catenin accumulation and S33F mutation of CTNNB1 gene in colorectal cancer in Saudi Arabia.

Several risk factors associated with colorectal cancer (CRC) have been identified including ß-catenin/CTNNB1 hotspot mutations. The levels of ß-catenin within a cell are regulated via phosphorylation of the N terminus of ß-catenin by GSK-3ß. Thus far three serines (S33, 37, 45) and one threonine (T41) are considered to be the substrates for GSK-3ß phosphorylation. In the present investigation an attempt was made to study the role of ß-catenin mutations in exon-3 in 60 colorectal cancer patients from Kingdom of Saudi Arabia (KSA). The hot spot mutation region of ß-catenin exon 3 was evaluated in matched tumor and normal tissues using PCR and direct sequencing. Sequencing of exon 3 of the CTNNB1 gene revealed an activating mutation (S33F) in one of the tumor samples as compared to the normal tissue from the same patient where there was no such mutation found. Immunohistochemical staining showed the accumulation of ß-catenin protein both in cytoplasm and in the nuclei of cancer cells as compared to normal tissue.

Genetic association between the HLA-G 14-bp insertion/deletion polymorphism and the recurrent spontaneous abortions in Saudi Arabian women.

The non-classical class I human leukocyte antigen (HLA)-G molecule was found to be predominately expressed in the extravillous cytotrophoblasts at the fetal-maternal interface during pregnancy. This molecule is critically important for successful implantation during human pregnancy. The polymorphic insertion-deletion (indel) 14-base pair (bp) site localized at the 3' untranslated region was associated with HLA-G mRNA stability and isoform alternative splicing patterns, and thus may influence HLA-G function during pregnancy. We studied the association between the 14-bp indel polymorphism (rs16375) at the 3' untranslated region with recurrent spontaneous abortions in a Saudi population living in Riyadh. A group of 64 women with 2-11 successive abortions were included in this study. The control group included 62 women without reported abortions and at least 2 pregnancies, all visiting the King Khaled Hospital in Riyadh. The 14-bp indel was genotyped in the case and control groups. The frequency of the genotype +14/+14 was slightly higher in women with recurrent spontaneous abortions, but no significant differences were observed in the distribution of alleles and genotypes.

Spurious correlations in surface-based functional brain imaging.

The study of functional MRI data is increasingly performed after mapping from volumetric voxels to surface vertices. Processing pipelines commonly used to achieve this mapping produce meshes with uneven vertex spacing, with closer neighbours in sulci compared to gyri. Consequently, correlations between the fMRI time series of neighbouring sulcal vertices are stronger than expected. However, the causes, extent, and impacts of this bias are not well understood or widely appreciated. We explain the origins of these biases, and using in-silico models of fMRI data, illustrate how they lead to spurious results. The bias leads to leakage of anatomical cortical folding information into fMRI time series. We show that many common analyses can be affected by this "gyral bias", including test-retest reliability, fingerprinting, functional parcellations, regional homogeneity, and brain-behaviour associations. Finally, we provide recommendations to avoid or remedy this spatial bias.

Prenatal exposure to acrylamide differently affected the sex ratio, aromatase and apoptosis in female adult offspring of two subsequent generations.

In the present study, we investigated the effect of acrylamide (ACR) exposure during pregnancy on the ovary of female adult offspring of two subsequent generations. Sixty-day-old Wistar albino female rats were given different doses of ACR (2.5 and 10 mg/kg/day) from day 6 of pregnancy until giving birth. Females from the first generation (AF1) were fed ad libitum, and thereafter, a subgroup was euthanized at 8 weeks of age and ovary samples were obtained. The remaining females were maintained until they reached sexual maturity (50 days old) and then treated in the same way as the previous generation to obtain the second generation of females (AF2). The histopathological examination indicated a high frequency of corpora lutea along with an increased number of antral follicles that reached the selectable stage mainly at a dose of 2.5 mg/kg/day. Interestingly, ACR exposure significantly increased the mRNA levels of CYP19 gene and its corresponding CYP19 protein expression in AF1 females. The TUNEL assay showed a significantly high rate of apoptosis in stromal cells except for dose of 2.5 mg/kg/day. However, in AF2 females, ACR exposure significantly increased the number of degenerating follicles and cysts while the number of growing follicles was reduced. Moreover, in both ACR-treated groups, estradiol-producing enzyme CYP19A gene and its corresponding protein were significantly reduced, and an excessive apoptosis was produced. We concluded that the ovarian condition of AF1 females had considerable similarity to the typical early perimenopausal stage, whereas that of AF2 females was similar to the late perimenopausal stage in women.

Peer-assisted versus expert-assisted learning in virtual chest x-ray interpretation: A randomized controlled trial.

OBJECTIVES: To compare the effectiveness of peer-assisted learning (PAL) and expert-assisted learning (EAL) in terms of knowledge gain in virtual chest x-ray (CXR) interpretations. The secondary objective was to assess students' satisfaction levels between both groups. METHODS: In this randomized controlled trial, second-year medical students who met the inclusion criteria were randomly assigned to the PAL and EAL groups. The study was carried out from December 2020 to February 2021 at Umm Al-Qura University, Makkah, Saudi Arabia. The primary endpoint was the difference in the students' scores, which were determined by an independent reviewer. The secondary endpoint was students' satisfaction levels. RESULTS: A total of 166 second year medical students were included. The standard deviation and mean age of the population were 19.73±0.66 (males: 79 [47.6%]; females: 87 [52.4%]). Participants were allocated equally into two groups (83 in each group). Student scores did not differ significantly between the two groups (p=0.507). Students in the PAL group thought the session was useful (p=0.01), kept on time (p=0.043), and the tutor facilitated their learning process (p=0.011). They also felt that online teaching was as effective as traditional teaching (p=0.03). There was no significant difference in satisfaction scores on the other aspects of the questionnaire. CONCLUSION: Peer-assisted learning has equivalent efficacy compared to EAL in a virtual setting. The Students in the PAL group had higher level of satisfaction.

Effect of contact lens material on cytotoxicity potential of multipurpose solutions using human corneal epithelial cells.

PURPOSE: Multipurpose solutions (MPS) are used daily to clean and disinfect silicone hydrogel (SiHy) contact lenses. This in vitro study was undertaken to identify the potential for interaction between MPS, SiHy surface treatments, and lens materials, which may lead to changes in the response of human corneal epithelial cells (HCEC) to MPS-soaked lenses. METHODS: The MPS tested were renu fresh (formerly known as ReNu MultiPlus; ReNu), OptiFree Express (OFX), OptiFree RepleniSH, SoloCare Aqua, and Complete Moisture Plus. The SiHy materials evaluated were lotrafilcon A, lotrafilcon B, comfilcon A, galyfilcon A, and balafilcon A (BA). MPS-soaked lenses were placed on top of adherent HCEC. The effect of MPS dilutions (0.1 to 10% final concentration in medium) was also characterized. Cell viability, adhesion phenotype and caspase activation were studied after 24-h cell exposure. OFX released from lenses was determined using UV absorbance. RESULTS: A significant reduction in viability (between 30 to 50%) was observed with cells exposed to lenses soaked in ReNu and OFX. A significant downregulation of α(3) and ß(1) integrins, with integrin expression ranging from 60% to 75% of control (cells with no lens), was also observed with OFX and ReNu-soaked lenses. With the exception of BA, all other lenses soaked in OFX resulted in significant caspase activation, whereby over 18% of cells stained positive for caspases. Minimal caspase activation was observed in cells exposed to ReNu and Solo soaked lenses. For both OFX and ReNu, exposing cells to at least a 5% dilution had a significant effect on viability and integrin expression. While Complete and Solo did not lead to reduction in viability, cells exposed to a 10% dilution showed reduced integrin expression down to less than 70% of control value. Comparing cell response to diluted MPS solutions and various MPS-soaked lenses showed that it is not possible to reliably use cell response to MPS dilution alone to assess MPS biocompatibility. CONCLUSIONS: Our results demonstrate that the reaction of HCEC to MPS are affected by the type of lenses the MPS is released from and may potentially be influenced by the surface treatment (or lack of it) of SiHy materials.

Brain-Predicted Age Associates With Psychopathology Dimensions in Youths.

BACKGROUND: This study aimed to investigate whether dimensional constructs of psychopathology relate to variation in patterns of brain development and to determine whether these constructs share common neurodevelopmental profiles. METHODS: Psychiatric symptom ratings from 9312 youths (8-21 years old) from the Philadelphia Neurodevelopmental Cohort were parsed into 7 independent dimensions of clinical psychopathology representing conduct, anxiety, obsessive-compulsive, attention, depression, bipolar, and psychosis symptoms. Using a subset of this cohort with structural magnetic resonance imaging (n = 1313), a normative model of brain morphology was established and the model was then applied to predict the age of youths with clinical symptoms. We investigated whether the deviation of brain-predicted age from true chronological age, called the brain age gap, explained individual variation in each psychopathology dimension. RESULTS: Individual variation in the brain age gap significantly associated with clinical dimensions representing psychosis (t = 3.16, p = .0016), obsessive-compulsive symptoms (t = 2.5, p = .01), and general psychopathology (t = 4.08, p < .0001). Greater symptom severity along these dimensions was associated with brain morphology that appeared older than expected for typically developing youths of the same age. Psychopathology dimensions clustered into 2 modules based on shared brain loci where putative accelerated neurodevelopment was most prominent. Patterns of morphological development were accelerated in frontal cortices for depression, psychosis, and conduct symptoms (module 1), whereas acceleration was most evident in subcortex and insula for the remaining dimensions (module 2). CONCLUSIONS: Our findings suggest that increased brain age, particularly in frontal cortex and subcortical nuclei, underpins clinical psychosis and obsessive-compulsive symptoms in youths. Psychopathology dimensions share common neural substrates, despite representing clinically independent symptom profiles.

Acroeimeria lineri (McAllister, Upton, Freed, 1988) Paperna and Landsberg, 1989 in Mediterranean Geckos (Hemidactylus turcicus): Oocyst Morphometrics, Endogenous Developmental Stages, and Molecular Sequencing Support its Placement into Acroeimeria.

Between June 2016 and June 2019, we surveyed 62 Mediterranean geckos, Hemidactylus turcicus, from Abu Rawash, Giza, Egypt, for the presence of endoparasites. In June 2016, we found 3 individuals to be infected with Eimeria lineri. We studied the morphology and inner structures of its sporulated oocysts, and the locations of its intestinal endogenous stages. We also extracted genomic DNA from these sporulated oocysts and successfully sequenced a 632-bp fragment of the 18S rRNA gene. Phylogenetic analyses using this partial sequence allowed us to support previous studies that assigned E. lineri to the genus Acroeimeria. Our consensus sequence was used to query similar 18S rDNA sequences from GenBank, and 14 sequences were selected. The phylogenetic analysis inferred by maximum likelihood and Bayesian inference methods gave similar results, as both separated the sequences into 2 clades: (1) a monophyletic group of Goussia species (from fish); and (2) a strongly supported clade that separated 4 Choleoeimeria species from a polyphyletic group of species that clustered A. lineri with 3 other Acroeimeria species and 3 Eimeria species from lizards, including Eimeria tiliquae from Tiliqua rugosa (Gray, 1825), Eimeria tokayae from Gecko gecko (L., 1758), and Eimeria eutropidis from Eutropis macularia (Blyth, 1853). Our study supports the placement of E. lineri into the Acroeimeria and contributes additional life history information toward understanding the evolutionary origin of the Eimeria-like species that have sporocysts without Stieda bodies in their oocysts and that infect saurian reptiles. We also support the concept that several traits (morphological, endogenous, and gene sequences) are both necessary and important for authors to include when making generic reassignments within the eimeriid coccidia.

Ru(ii)-N-heterocyclic carbene complexes: synthesis, characterization, transfer hydrogenation reactions and biological determination.

A series of ruthenium(ii) complexes with N-heterocyclic carbene ligands were successfully synthesized by transmetalation reactions between silver(i) N-heterocyclic carbene complexes and [RuCl2(p-cymene)]2 in dichloromethane under Ar conditions. All new compounds were characterized by spectroscopic and analytical methods. These ruthenium(ii)-NHC complexes were found to be efficient precatalysts for the transfer hydrogenation of ketones by using 2-propanol as the hydrogen source in the presence of KOH as a co-catalyst. The antibacterial activity of ruthenium N-heterocyclic carbene complexes 3a-f was measured by disc diffusion method against Gram positive and Gram-negative bacteria. Compounds 3d exhibited potential antibacterial activity against five bacterial species among the six used as indicator cells. The product 3e inhibits the growth of all the six tested microorganisms. Moreover, the antioxidant activity determination of these complexes 3a-f, using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) as reagent, showed that compounds 3b and 3d possess DPPH and ABTS antiradical activities. From a concentration of 1 mg ml-1, these two complexes presented a similar scavenging activity to that of the two used controls gallic acid (GA) and butylated hydroxytoluene (BHT). From a concentration of 10 mg ml-1, the percentage inhibition of complexes 3b and 3d was respectively 70% and 90%. In addition, these two Ru-NHC complexes exhibited antifungal activity against Candida albicans. Investigation of the anti-acetylcholinesterase activity of the studied complexes showed that compounds 3a, 3b, 3d and 3e exhibited good activity at 100 µg ml-1 and product 3d is the most active. In a cytotoxicity study the complexes 3 were evaluated against two human cancer cell lines MDA-MB-231 and MCF-7. Both 3d and 3e complexes were found to be active against the tested cell lines showing comparable activity with examples in the literature.

Treatment of effluents from cardboard industry by coagulation-electroflotation.

The objective of the present study is to optimize the treatment of the cardboard industry wastewater generated in the process of machine washing. This type of effluent is usually treated by traditional physicochemical processes such as coagulation/flocculation and sedimentation. These processes give a limited purifying efficiency, particularly for the COD reduction. In this work, the treatment by coagulation-electroflotation process was adopted. In batch mode treatment, current density, pH and coagulant concentration are the operating parameters to optimize. The methodology of experimental research, with an orthogonal central composite plan was adopted. Good agreement between theoretical analysis and experimental results was obtained. Continuous mode was also studied in order to optimize the residence time. A physicochemical characterization including COD, BOD and suspended solids charge was done before and after the treatment in order to improve the efficiency of this process.