Effect of Fiber-Reinforced Composite Placement Site on Fracture Resistance of Premolar Teeth: An in vitro Study.

Background: This study aimed to investigate the fracture behavior of upper premolars with deep MOD cavities that were restored with Ribbond resin-reinforced fibers (FRCs) placed in different orientations. Methods: A total of 54 extracted maxillary premolars were randomly divided into nine groups. The experimental groups underwent MOD cavity preparation with or without root canal treatment, followed by FRCs placed in the pulpal floor, proximal walls, or both. Fracture resistance was tested using an Instron Machine. The samples were visually inspected to analyze the fracture mode. Results: The highest fracture resistance was observed in intact teeth (1299.98 ± 284.66 MPa). Placing Ribbond fibers in the pulpal floor (1155.86 ± 244.21 MPa) or the proximal walls (1077.56 ± 260.60 MPa) significantly improved fracture resistance (p= <0.05), compared to cavities restored with only resin composite (804.58 ± 93.34 MPa). However, placing Ribbond fibers in both the pulpal and proximal walls did not enhance fracture resistance. In the MOD-RCT groups, fracture resistance was improved only when Ribbond fibers were placed in the pulpal floor and the proximal walls. Fracture mode analysis revealed a combined fracture in most of the groups. Conclusion: This study concluded that using FRCs significantly improved the fracture resistance of MOD cavities in premolars and revealed that the placement site could be a determinant factor.

This study investigated the fracture behavior of upper premolars with deep MOD cavities restored with Ribbond resin-reinforced fibers (FRCs) placed in different orientations.Placing Ribbond fibers in the pulpal floor or the proximal walls significantly improved the fracture resistance of premolars with deep MOD cavities.In the MOD-RCT groups, fracture resistance was improved only when Ribbond fibers were placed in the pulpal floor and the proximal walls.Fracture mode analysis revealed a combined fracture in most of the groups. This study concluded that using FRCs significantly improved the fracture resistance of MOD cavities in premolars and revealed that the placement site could be a determinant factor.

Design, synthesis, antineoplastic activity of new pyrazolo[3,4-d]pyrimidine derivatives as dual CDK2/GSK3ß kinase inhibitors; molecular docking study, and ADME prediction.

In the current study, novel pyrazolo[3,4-d]pyrimidine derivatives 5a-h were designed and synthesized as targeted anti-cancer agents through dual CDK2/GSK-3ß inhibition. The designed compounds demonstrated moderate to potent activity on the evaluated cancer cell lines (MCF-7 and T-47D). Compounds 5c and 5 g showed the most promising cytotoxic activity against the tested cell lines surpassing that of the used reference standard; staurosporine. On the other hand, both compounds showed good safety and tolerability on normal fibroblast cell line (MCR5). The final compounds 5c and 5 g showed a promising dual CDK2/GSK-3ß inhibitory activity with IC50 of 0.244 and 0.128 µM, respectively, against CDK2, and IC50 of 0.317 and 0.160 µM, respectively, against GSK-3ß. Investigating the effect of compounds 5c and 5 g on CDK2 and GSK-3ß downstream cascades showed that they reduced the relative cellular content of phosphorylated RB1 and ß-catenin compared to that in the untreated MCF-7 cells. Moreover, compounds 5c and 5 g showed a reasonable selective inhibition against the target kinases CDK2/GSK-3ß in comparison to a set of seven off-target kinases. Furthermore, the most potent compound 5 g caused cell cycle arrest at the S phase in MCF-7 cells preventing the cells' progression to G2/M phase inducing cell apoptosis. Molecular docking studies showed that the final pyrazolo[3,4-d]pyrimidine derivatives have analogous binding modes in the target kinases interacting with the hinge region key amino acids. Molecular dynamics simulations confirmed the predicted binding mode by molecular docking. Moreover, in silico predictions indicated their favorable physicochemical and pharmacokinetic properties in addition to their promising cytotoxic activity.

QTAIM analysis of the bonding in anionic group 6 carbonyl selenide clusters: [Se2M3(CO)10]2- (M=Cr, Mo, W).

CONTEXT: This research aims to offer a deeper understanding of the bonding interactions between M-Se and M-CO and how these interactions change across the group 6 transition metal series: [Se2M3(CO)10]2- (M = Cr, Mo, W). It also seeks to explore the impact of carbonyl groups on M-M interactions within the clusters. Seven criteria, which are based on QTAIM properties, have been considered and compared with the corresponding criteria in other transition metal clusters. The results confirm that no such bond critical points or bond baths occur between transition metals, which instead have 5c-7e bonding interactions delocalized over their five-membered M3(µ-Se)2 ring, as evidenced by the non-negligible nonbonding delocalization indices. The topological properties of three bond clusters, Cr-Se, Mo-Se, and W-Se, resemble those of "intermediate closed shell characters," which combine covalent and electrostatic properties. Source function calculations indicated that the bonded Se atom contributed the most to each Cr-Se and Mo-Se bcp. The OCO atoms and nonbonded Se atoms also contributed to some extent. However, metal atoms act as sinks rather than as sources of electron density. In contrast, the majority of the metal atoms, both bonded and nonbonded, contribute to Cr-W bcps. Analysis of the delocalization indices δ(M…O) in the three clusters indicates that CO significantly contributes to Cr π-back donation in cluster 1. In contrast, no π-back donation occurs from CO to Mo or W in clusters 2 or 3, respectively. METHODS: The B3P86 hybrid functional was used for computations in the Gaussian 09 software. The LanL2DZ basis set was employed for Cr, Mo, and W, while the 6-31G (d, p) basis set was used for C, O, and Se atoms. We performed QTAIM analysis using the AIM2000 and Multiwfn packages, incorporating B3P86/WTBS for Cr, Mo, and W atoms. The 6-311++G(3df,3pd) basis set was used for C, O, and Se atoms. Additionally, we utilized the ELF and SF.

Effect of temperature, salinity and nutrients on the growth and toxin content of the dinoflagellate Gymnodinium catenatum from the southwestern Mediterranean.

The dinoflagellate Gymnodinium catenatum is considered the primary cause of recurrent paralytic shellfish toxins (PSTs) in shellfish on the Moroccan Mediterranean coasts. The impacts of key environmental factors on the growth, cell yield, cell size and PST content of G. catenatum were determined. Results indicated that increasing salinity from 32 to 39 and nitrate concentrations from 441 µM to 1764 µM did not significantly (ANOVA, P-value >0.63) modify the growth rate of the studied species. Gymnodinium catenatum exhibited the highest growth rate at 24 °C. Cells arrested their division at 15 °C and at ammonium concentration above 441 µM, suggesting that this nitrogen form is toxic for G. catenatum. Furthermore, G. catenatum was unable to assimilate urea as a nitrogen source. In G. catenatum cells, eight analogues of saxitoxin were detected, belonging to the N-sulfocarbamoyl (C1-4, B1 and B2) and decarbamoyl (dc-GTX2/3) toxins. C-toxins contributed 92 % to 98 % of the molar composition of the PSTs. During the exponential growth, C2 tended to dominate, while C3 prevailed during the stationary phase. Toxin content per cell (ranging from 5.5 pg STXeq.cell-1 to 22.4 pg STXeq.cell-1) increased during the stationary growth phase. Cell toxin content increased with the concentrations of nitrate, ranging from 12.1 pg STXeq.cell-1 at 441 µM to 22.4 pg STXeq.cell-1 at 1764 µM during the stationary growth phase. The toxin content of G. catenatum showed the highest values measured at the highest tested temperatures, especially during the stationary phase, where toxicity reached 17.8 pg STXeq.cell-1 and 16.4 pg STXeq.cell-1 at 24 °C and 29 °C, respectively. The results can help understand the fluctuations in the growth and PST content of G. catenatum in its habitat in response to changing environmental variables in the Mediterranean Sea when exposed to increases in warming pressure and eutrophication.

Understanding iron homeostasis in MDS: the role of erythroferrone.

Myelodysplastic neoplasms (MDS) are a heterogenous group of clonal stem cell disorders characterized by dysplasia and cytopenia in one or more cell lineages. Anemia is a very common symptom that is often treated with blood transfusions and/or erythropoiesis stimulating factors. Iron overload results from a combination of these factors together with the disease-associated ineffective erythropoiesis, that is seen especially in MDS cases with SF3B1 mutations. A growing body of research has shown that erythroferrone is an important regulator of hepcidin, the master regulator of systemic iron homeostasis. Consequently, it is of interest to understand how this molecule contributes to regulating the iron balance in MDS patients. This short review evaluates our current understanding of erythroferrone in general, but more specifically in MDS and seeks to place in context how the current knowledge could be utilized for prognostication and therapy.

Granulomatous mastitis in accessory breast tissue: A rare presentation and surgical management.

Granulomatous mastitis (GM) in accessory breast tissue is rare. The present study aimed to report a rare case of GM in accessory breast tissue. A 39-year-old female patient presented with right axillary discomfort and swelling for ~5 days. On clinical examination, a tender, firm lump was detected in the right axillary region. The ultrasound showed diffuse parenchymal heterogeneity and surrounding edema in the right accessory breast associated with reactive axillary lymph nodes. Following unresponsiveness to conservative treatment, a surgical procedure was performed in the form of an excisional biopsy and the lesion was diagnosed as GM. During the six-month follow-up, there were no recurrences. The exact cause of GM remains uncertain and the etiology within accessory breast tissue is even less understood. Proposed mechanisms suggest that it may result from an exaggerated immune response triggered by various factors, such as infection, autoimmunity or hormonal fluctuations. GM in accessory breast tissue is a rare and challenging clinical condition to be diagnosed. Due to the rarity of this condition, it highlights the importance of including GM in the differential diagnosis of axillary masses.

Case report: Contraceptive implant migration.

Subdermal contraceptive implants are one of the effective and reversible methods of contraception available today. Implanon is a Saudi FDA-approved contraceptive that is commonly used by the Saudi population. Along with their hormonal side effects such as mood changes and acne, subdermal contraceptive implants can also lead to more life-threatening, albeit rare, mishaps, such as the deeper migration of them into the axillary and thoracic structures. Only a few cases exist in the literature regarding these rare complications. In this case report, we describe the case of a 31-year-old woman presenting with ulnar neuropathy due to deep proximal migration 3 years after the insertion of an Implanon. The foreign body was removed using intraoperative image-enhancing fluoroscopy, with neurological symptoms being resolved as a result.

Histone Deacetylase Inhibitors Directly Modulate T Cell Gene Expression and Signaling and Promote Development of Effector-Exhausted T Cells in Murine Tumors.

Epigenetic regulation plays a crucial role in the development and progression of cancer, including the regulation of antitumor immunity. The reversible nature of epigenetic modifications offers potential therapeutic avenues for cancer treatment. In particular, histone deacetylase (HDAC) inhibitors (HDACis) have been shown to promote antitumor T cell immunity by regulating myeloid cell types, enhancing tumor Ag presentation, and increasing expression of chemokines. HDACis are currently being evaluated to determine whether they can increase the response rate of immune checkpoint inhibitors in cancer patients. Although the potential direct effect of HDACis on T cells likely impacts antitumor immunity, little is known about how HDAC inhibition alters the transcriptomic profile of T cells. In this article, we show that two clinical-stage HDACis profoundly impact gene expression and signaling networks in CD8+ and CD4+ T cells. Specifically, HDACis promoted T cell effector function by enhancing expression of TNF-α and IFN-γ and increasing CD8+ T cell cytotoxicity. Consistently, in a murine tumor model, HDACis led to enrichment of CD8+ T cell subsets with high expression of effector molecules (Prf1, Ifng, Gzmk, and Grmb) but also molecules associated with T cell exhaustion (Tox, Pdcd1, Lag3, and Havcr2). HDACis further generated a tumor microenvironment dominated by myeloid cells with immune suppressive signatures. These results indicate that HDACis directly and favorably augment T cell effector function but also increase their exhaustion signal in the tumor microenvironment, which may add a layer of complexity for achieving clinical benefit in combination with immune checkpoint inhibitors.

Synthesis, Characterization, and Anticancer Activity of New N,N'-Diarylthiourea Derivative against Breast Cancer Cells.

The goal of the current study was to prepare two new homologous series of N,N'-diarylurea and N,N'-diarylthiourea derivatives to investigate the therapeutic effects of these derivatives on the methodologies of inhibition directed on human MCF-7 cancer cells. The molecular structures of the prepared derivatives were successfully revealed through elemental analyses, 1H-NMR, 13C-NMR and FT-IR spectroscopy. The cytotoxic results showed that Diarylthiourea (compound 4) was the most effective in suppressing MCF-7 cell growth when compared to all other prepared derivatives, with the most effective IC50 value (338.33 ± 1.52 µM) after an incubation period of 24 h and no cytotoxic effects on normal human lung cells (wi38 cells). Using the annexin V/PI and comet tests, respectively, treated MCF-7 cells with this IC50 value of the Diarylthiourea 4 compound displayed a considerable increase in early and late apoptotic cells, as well as an intense comet nucleus in comparison to control cells. An arrest of the cell cycle in the S phase was observed via flow cytometry in MCF-7 cells treated with the Diarylthiourea 4 compound, suggesting the onset of apoptosis. Additionally, ELISA research showed that caspase-3 was upregulated in MCF-7 cells treated with compound 4 compared to control cells, suggesting that DNA damage induced by compound 4 may initiate an intrinsic apoptotic pathway and activate caspase-3. These results contributed to recognizing that the successfully prepared Diarylthiourea 4 compound inhibited the proliferation of MCF-7 cancer cells by arresting the S cell cycle and caspase-3 activation via an intrinsic apoptotic route. These results, however, need to be verified through in vivo studies utilizing an animal model.

A comparative review of the mineralogical and chemical composition of African major bauxite deposits.

Bauxite, which is the main raw material that aluminium is extracted from was discovered in Africa in the early 1900s. Currently, the production and export capacities of the African Bauxite ore are about a third of the World's total capacity. However, the processes leading to the final finished product of; surface mining of the ore, refining ore into alumina and finally extracting the pure aluminium metal in high energy consuming smelters that employ the Hall-Héroult electrolysis process; seldom take place inside Africa. The main goal of this work is to analyse the mineralogical and geochemical characteristics of bauxite deposits from some prominent bauxite producing and exporting countries of Africa in order to fashion out if a trend exist for the type of source rocks. Judging from the data obtained, gibbsite is found to be the main aluminium oxide in all the bauxite deposits with slight occurrence of boehmite in 3 out of the 13 deposits, while goethite is the main oxyhydroxide iron mineral. The compiled results of the various investigations highlighted the fact that the deposits are of diverse qualities with respect to world standard of major element content of bauxite; with average percentage concentration in the ranges as: Al2O3 (43.73-61.25), Fe2O3 (1.55-34.25), SiO2 (0.42-10.84); except two of the deposits with alumina content less than 40%. With evaluated silica moduli less than 8 for only two (2) of the deposits (4.76 and 6.94), the rest have higher moduli that ranges between (14.49 and 75.45). The higher percentage of iron oxide content (>20) in six (6) out of the 13 ore deposits, allowed the deposits to be grouped into three (3) categories of grades; high alumina ore, ferruginous ore, siliceous ore and combination of each. Source rock of the deposits were determined through geochemical and petrographic considerations of laterisation products of the rocks through evaluation of the weathering indices of; Chemical Index of Alteration which was in the range (97.16-99.98) while the Ruxton ratio ranged between (0.0133-0.2100); signifying the parent rock underwent intensive weathering process. This is indicative of the source rocks of the Bauxite deposits being either (i) anorthositic, (ii) argillite and dolerite, (iii) granulite and feldspathic gneiss, and/or, (iv) mafic-basaltic andesite igneous. Awareness of new and yet-to-commence emerging bauxite producing African countries was created, by highlighting the economic impact those respective countries will experience when that mining sector is developed for the aluminum industry at home and world at large.

Synthesis of New Liquid-Crystalline Compounds Based on Terminal Benzyloxy Group: Characterization, DFT and Mesomorphic Properties.

The effect of the terminal benzyloxy group on the mesomorphic properties of liquid crystalline materials developed from rod-like Schiff base has been described. For this objective, a novel Schiff base liquid crystal family, specifically new series of Schiff base liquid crystals, namely, (E)-4-(alkyloxy)-N-(4-(benzyloxy)benzylidene)aniline, In, are prepared and investigated in detail. The length of the terminal alkyloxy chain (n) varies amongst the compounds in the series. Where n varies between 6, 8 and 16 carbons. At the other end of the compounds, benzyloxy moiety was attached. The molecular structures of all synthesized compounds were established using different spectroscopic techniques. The molecular self-assembly was explored using differential scanning calorimetry (DSC) and polarized optical microscope (POM). Depending on the length of the terminal alkyloxy chain, only one type of SmA phase with different stability was observed. The previously reported para-substituted systems and the present investigated compounds were compared and discussed. The calculated quantum chemical parameters were computationally correlated using the DFT method via the B3LYP 6-311G(d,p) basis set. The theoretical computations revealed that the length of the alkyl side chain influences the zero-point energy, reactivity and other estimated thermodynamic parameters of benzoyloxy/azomethine derivatives. Furthermore, the FMO energy analysis shows that molecule I16 have higher HOMO energies than the other compounds, and I6 has a much lower LUMO level than the rest.

The Neutrophil-to-Lymphocyte-Ratio as Diagnostic and Prognostic Tool in Sepsis and Septic Shock.

BACKGROUND: Studies investigating the diagnostic and prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in sepsis or septic shock commonly included preselected subgroups of patients or were published prior to the current sepsis-3 criteria. Therefore, this study investigates the diagnostic and prognostic impact of the NLR in patients with sepsis and septic shock. METHODS: Consecutive patients with sepsis and septic shock from 2019 to 2021 from the prospective "MARSS-registry" were included monocentrically. First, the diagnostic value of the NLR compared to established sepsis scores was tested for septic shock compared to sepsis. Second, the diagnostic value of the NLR with regard to positive blood cultures was tested. Thereafter, the prognostic value of the NLR was tested for 30-day all-cause mortality. Statistical analyses included univariable t-tests, Spearman´s correlations, C-statistics, Kaplan-Meier analyses, Cox proportional regression analyses as well as uni- and multivariate logistic regression models. RESULTS: A total of 104 patients were included, of which 60% were admitted with sepsis and 40% with septic shock. The overall rate of all-cause mortality at 30 days was 56%. With an area under the curve (AUC) of 0.492, the NLR was shown to have a poor diagnostic value with regard to the diagnosis of septic shock compared to sepsis. However, the NLR was shown to be a reliable parameter to discriminate between patients with negative and positive blood cultures when admitted with septic shock (AUC = 0.714). This was still evident after multivariable adjustment (OR = 1.025; 95% CI 1.000 - 1.050; p = 0.048). In contrast, the NLR revealed a poor prognostic accuracy (AUC = 0.507) with regard to 30-day all-cause mortality. Finally, a higher NLR was not associated with an increased risk of 30-day all-cause mortality (log rank p-value = 0.775). CONCLUSIONS: The NLR was a reliable diagnostic tool for the identification of patients with blood culture confirmed sepsis. Yet, the NLR was not a reliable parameter to discriminate between patients with sepsis and septic shock nor between 30-day survivors and non-survivors.

Synthesis and characterization of new imine liquid crystals based on terminal perfluoroalkyl group.

New organic derivatives named, (E)-3(or4) -(alkyloxy)-N-{(trifluoromethyl)benzylidene}aniline, 1a-f, were synthesized and examined their liquid crystalline behaviors. FT-IR, 1H NMR, 13C NMR, 19F NMR, elemental analyses and GCMS were used to validate the prepared compounds' chemical structures. We used differential scanning calorimetry (DSC) and polarized optical microscopy (POM) to investigate the mesomorphic characteristics of the formed Schiff bases. All tested compounds of series 1a-c have mesomorphic behaviour of nematogenic temperature ranges while the group 1d-f show non-mesomorphic properties. Moreover, it was found that the enantiotropic N phases included all of the homologue 1a-c. Computational studies using DFT (density functional theory) validated the experimental mesomorphic behavior results. All the analyzed compounds had their dipole moments, polarizability, and reactivity characteristics explained. Theoretical simulations showed that as the length of the terminal chain is increased, the polarizability of the stuided compounds increases. Consequently, compounds 1a and 1d have the least polarizability.

Combination IFNß and Membrane-Stable CD40L Maximize Tumor Dendritic Cell Activation and Lymph Node Trafficking to Elicit Systemic T-cell Immunity.

Oncolytic virus therapies induce the direct killing of tumor cells and activation of conventional dendritic cells (cDC); however, cDC activation has not been optimized with current therapies. We evaluated the adenoviral delivery of engineered membrane-stable CD40L (MEM40) and IFNß to locally activate cDCs in mouse tumor models. Combined tumor MEM40 and IFNß expression induced the highest cDC activation coupled with increased lymph node migration, increased systemic antitumor CD8+ T-cell responses, and regression of established tumors in a cDC1-dependent manner. MEM40 + IFNß combined with checkpoint inhibitors led to effective control of distant tumors and lung metastases. An oncolytic adenovirus (MEM-288) expressing MEM40 + IFNß  in phase I clinical testing induced cancer cell loss concomitant with enhanced T-cell infiltration and increased systemic presence of tumor T-cell clonotypes in non-small cell lung cancer (NSCLC) patients. This approach to simultaneously target two major DC-activating pathways has the potential to significantly affect the solid tumor immunotherapy landscape.

Risk Factors for Ebola Virus Persistence in Semen of Survivors in Liberia.

BACKGROUND: Long-term persistence of Ebola virus (EBOV) in immunologically privileged sites has been implicated in recent outbreaks of Ebola virus disease (EVD) in Guinea and the Democratic Republic of Congo. This study was designed to understand how the acute course of EVD, convalescence, and host immune and genetic factors may play a role in prolonged viral persistence in semen. METHODS: A cohort of 131 male EVD survivors in Liberia were enrolled in a case-case study. "Early clearers" were defined as those with 2 consecutive negative EBOV semen test results by real-time reverse-transcription polymerase chain reaction (rRT-PCR) ≥2 weeks apart within 1 year after discharge from the Ebola treatment unit or acute EVD. "Late clearers" had detectable EBOV RNA by rRT-PCR >1 year after discharge from the Ebola treatment unit or acute EVD. Retrospective histories of their EVD clinical course were collected by questionnaire, followed by complete physical examinations and blood work. RESULTS: Compared with early clearers, late clearers were older (median, 42.5 years; P < .001) and experienced fewer severe clinical symptoms (median 2, P = .006). Late clearers had more lens opacifications (odds ratio, 3.9 [95% confidence interval, 1.1-13.3]; P = .03), after accounting for age, higher total serum immunoglobulin G3 (IgG3) titers (P = .005), and increased expression of the HLA-C*03:04 allele (0.14 [.02-.70]; P = .007). CONCLUSIONS: Older age, decreased illness severity, elevated total serum IgG3 and HLA-C*03:04 allele expression may be risk factors for the persistence of EBOV in the semen of EVD survivors. EBOV persistence in semen may also be associated with its persistence in other immunologically protected sites, such as the eye.

Postoperative myoclonic movement following mandibular cyst enucleation under general anesthesia: A case report.

Postoperative myoclonic movement (PMM) is an uncommon side effect after general anesthesia (GA), and the exact cause of this neurologic complication is still unknown. Many factors such as anesthesia, psychological stresses, and surgical stress could trigger PMM. We are here reporting a case of PMM in the post-anesthetic care unit (PACU) following general anesthesia in an apparently healthy patient.

An overview of pathophysiology and treatment options of osteonecrosis of femoral head in sickle cell disease.

Osteonecrosis of the femoral head (ONFH) is the most prevalent musculoskeletal pathologic manifestation of sickle cell disease (SCD) resulting in an osteonecrotic event. This review aimed to summarize mechanisms involved in pathophysiology of ONFH and treatment options available in Saudi Arabia to treat SCD patients with complication of osteonecrotic event. The pathophysiology of ONFH include genetic and micro particles involvement. The progression of osteonecrosis involves reduced levels of bioactive compounds in peripheral blood mononuclear cells and elevated CD4+T circulating levels to stimulate pro-inflammatory cytokines contributing to inflammation at target site. Initial treatment approach is pharmacological agents use to mitigate risk. Further, bone morphogenetic protein stimulation initiate bone formation and treatment can be improved with the use of bone morphogenetic protein, total hip arthroplasty and cell therapies. This review provides baseline information for future studies to be carried out in Saudi Arabia to improve treatment options in SCD patients with ONFH.

Development of harmful algal blooms species responsible for lipophilic and amnesic shellfish poisoning intoxications in southwestern Mediterranean coastal waters.

Mediterranean waters have undergone environmental changes during the last decades leading to various modifications of the structure of phytoplankton populations, especially Harmful Algal Blooms (HABs) species. Monitoring of the potentially toxic phytoplankton species was carried out biweekly in the western Mediterranean coast of Morocco from March 2018 to March 2019. Lipophilic Shellfish Toxins (LSTs) using LC-MS/MS and Domoic Acid (DA) using HPLC-UV were measured in the exploited mollusks, the cockle Acanthocardia tuberculata and the smooth clam Callista chione. We also determined the prevailing environmental factors in four surveyed sites (M'diq bay, Martil, Kaa Asras, and Djawn) selected to cover a variety of coastal ecosystems. Results showed that Pseudo-nitzschia spp. a DA producer species, was abundant with a pick of 50 × 103 cells l-1 on October 2018 in Djawn. Dinophysis caudata was the dominate Dinophysis species and showed a maximum density of 2200 cells l-1 on July in Djawn. Prorocentrum lima, an epibenthic dinoflagellate, appeared rarely in the water column with densities <80 cells l-1. Gonyaulax spinifera and Protoceratium reticulatum were found occasionally with a maximum density of 160 cells l-1. Karenia selliformis was detected only five times (<80 cells l-1) throughout the survey period. LC-MS/MS analyses revealed the presence of OA/DTX3, PTX-2, PTX-2 sa, and PTX-2 sa epi in the cockle at concentrations of up to 44.81 (OA/DTX-3+PTXs) ng g-1 meat. GYM-A was detected in the clam at concentrations of up to 4.22 ng g-1 meat. For the first time, AZAs and YTXs were detected in the southwestern Mediterranean with maximum values of 2.49 and 10.93 ng g-1 meat of cockle, respectively. DA was detected in moderate concentrations not exceeding 5.65 µg g-1 in both mollusks. Results showed that the observed toxic algae in the water column were responsible from the analysed toxins in the mollusks. It is likely that the southwestern Mediterranean waters could see the development of emergent species producing potent toxins (YTXs, AZAs, GYM-A). These dinoflagellates have to be isolated, ribotyped, and their toxin profiles determined.

Occurrence of three dominant epibenthic dinoflagellates (Ostreopsis spp., Coolia monotis and Prorocentrum lima) in relation to biotic substrates and environmental factors in a highly dynamic ecosystem, the Strait of Gibraltar (Southwestern Mediterranean).

No studies have been carried out on the benthic harmful algal blooms (BHABs) along the Strait of Gibraltar in the Mediterranean, and little is known about the diversity of blooming species. Here, epibenthic dinoflagellates were monitored at least biweekly over 18 months (May 2019-November 2020) in Oued Lihoud, Cap Malabata and Dalia on the thalli of five dominant macrophytes and in the water column. This is the first report on the seasonal distribution of BHAB species hosted by natural biotic substrates in the Strait of Gibraltar, which is known for high hydrodynamics, major entry of Atlantic waters and important maritime traffic. Three BHAB dinoflagellates were observed in the surveyed areas: Ostreopsis spp., Coolia monotis and Prorocentrum lima. The analysis of all data at the three sites showed that Dictyota dichotoma was the most favourable macroalgae host for these benthic dinoflagellates. The highest cell densities were observed in Cap Malabata for Ostreopsis spp. (2.7 × 105 cells/g fresh weight in September 2020), P. lima (4.57 × 104 cells/g FW in September 2020) and C. monotis (4.07 × 104 cells/g FW in June 2019). Phosphate and temperature were positively correlated to the abundances of the studied thermophilic BHAB species. In contrast, negative correlations were recorded with salinity, ammonium, nitrite, nitrate, DIN, nitrogen/phosphate ratio and suspended material, attesting of the complex relationships between environmental factors and BHAB species dynamic in each marine ecosystem. Toxin analyses of the natural phytoplankton assemblage during BHABs showed the presence of only lipophilic toxins, namely okadaic acid and dinophysistoxins produced by P. lima. These BHABs species have to be isolated to establish monoclonal cultures for ribotyping and ecophysiological investigations.

Repeated Impact Response of Normal- and High-Strength Concrete Subjected to Temperatures up to 600 °C.

With the aim of investigating the response of concrete to the dual effect of accidental fire high temperatures and possible induced impacts due to falling fragmented or burst parts or objects, an experimental work is conducted in this study to explore the influence of exposure to temperatures of 200, 400 and 600 °C on the responses of concrete specimens subjected to impact loads. Cylindrical specimens are tested using the recommended repeated impact procedure of the ACI 544-2R test. Three concrete mixtures with concrete nominal design strengths of 20, 40 and 80 MPa are introduced to represent different levels of concrete strength. From each concrete mixture, 24 cylinders and 12 cubes are prepared to evaluate the residual impact resistance and compressive strength. Six cylindrical specimens and three cubes from each concrete mixture are heated to each of the three levels of high temperatures, while the other six cylinders and three cubes are tested without heating as reference specimens. The test results show that the behavior of impact resistance is completely different from that of compressive strength after exposure to high temperatures; the cylindrical specimens lose more than 80% of the cracking and failure impact resistance after exposure to 200 °C, while impact resistance almost vanishes after exposure to 400 and 600 °C. Concrete compressive strength is found to be effective on the unheated impact specimens, where the higher-strength cylinders retain significantly higher impact numbers. This effect noticeably decreases after exposure to 200 and 400 °C, and vanishes after exposure to 600 °C.