Meroditerpenoids and derivatives from the brown alga Cystoseira baccata and their antifouling properties

The brown alga Cystoseira baccata harvested along the Atlantic coasts of Morocco yielded seven new meroditerpenoids (1-4) and derivatives (5-7), whose chemical structures were elucidated mainly by 2D NMR and mass spectrometry. Surprisingly, for all these compounds, which possess a bicyclo[4.3.0]nonane ring system, a trans fusion of the bicyclic system was deduced by stereochemical studies even though such compounds isolated from Cystoseira species are known to have a typical cis orientation for the bridgehead methyls. The antifouling and antibacterial activities of compounds 1-5 and 7 were evaluated, as well as their toxicity toward nontarget species. Compounds 4, 5, and 7 showed antifouling activities against growth of microalgae, macroalgal settlement, and mussel phenoloxidase activity, while being nontoxic to larvae of sea urchins and oysters.     

Carrier frequency of autosomal-recessive disorders in the Ashkenazi Jewish population: should the rationale for mutation choice for screening be reevaluated?

BACKGROUND: Ashkenazi Jewish (AJ) population is at increased risk for several recessive inherited diseases. Therefore, carrier testing of AJ members is important in order to identify couples at risk of having offspring with an autosomal recessive disorder. METHODS: In the present study, a database containing the results of 28 410 genotyping assays was screened. Ten thousand seventy eight nonselected healthy members of the AJ population were tested for carrier status for the following diseases; Gaucher disease (GD), cystic fibrosis (CF), Familial dysautonomia (FD), Alpha 1 antitrypsin (A1AT), Mucolipidosis type 4 (ML4), Fanconi anemia type C (FAC), Canavan disease (CD), Neimann-Pick type 4 (NP) and Bloom syndrome (BLM). RESULTS: The results demonstrated that 635 members were carriers of one mutation and 30 members were found to be carriers of two mutations in the different genes related to the development of the above mentioned diseases. GD was found to have the highest carrier frequency (1:17) followed by CF (1:23), FD (1:29), A1AT (1:65), ML4 (1:67) and FAC (1:77). The carrier frequency of CD, NP and BLM was 1:82, 1:103 and 1:157, respectively. CONCLUSIONS: The frequency of the disease-causing mutations screened routinely among the AJ population indicated that there are rare mutations with very low frequencies. The screening policy of the disease-causing mutations should be reevaluated and mutations with a high frequency should be screened, while rare mutations with a lower frequency may be tested in partners of carriers.     

Diluted magnetic semiconductor properties in TM doped ZnO nanoparticles

The hydrothermal method was used to create dilute magnetic semiconductor nanoparticles of Zn_1−xCo_xO (x = 0, 0.01, 0.05, 0.09). The effect of cobalt doping on the microstructure, morphological and optical properties of Zn_1−xCo_xO was also studied and the Co doping to host ZnO was confirmed from XRD and EDX analysis. The structural analysis showed that doping of cobalt into ZnO decreased the crystallinity, but the preferred orientation didn''t change. SEM analysis revealed that the cobalt dopant did not have a strong influence on the shape of the synthesized nanoparticles. No defect-related absorption peaks were observed in the UV-Vis spectra. The crystallinity of the doped samples was improved by high growth temperature and long growth time. Ferromagnetic behavior above room temperature was detected in co-doped ZnO nanoparticles. The ferromagnetic behavior increased with increasing Co (up to x = 0.05) doping. The ferromagnetic behavior declined when the Co content was further increased. Related research shows that doped ZnO nanoparticles have better dielectric, electrical conductivity, and magnetic properties than pure ZnO. This high ferromagnetism is usually a response reported for dilute magnetic semiconductors. These semiconductor nanoparticles were further used to designed spintronic based applications.

The enlarged central part M–H loop shows for the Co = 0.09 doped ZnO sample, the ferromagnetic (FM) behavior increased, i.e., a M_r of 0.2412 emu g⁻¹ with a H_c of 85 Oe.     

Valorization of Rice Husk and Straw Agriculture Wastes of Eastern Saudi Arabia: Production of Bio-Based Silica,Lignocellulose, and Activated Carbon

Bio-based silica, lignocellulose, and activated carbon were simply produced via the recycling of Hassawi rice biomass waste of Al-Ahsa governorate in the eastern Saudi Arabia region using a fast chemical treatment procedure. Rice husk and rice straw wastes were collected, ground, and chemically treated with sodium hydroxide to extract silica/silicate from the dried plant tissues. The liquid extract is then treated with acid solutions in order to precipitate silica/silicate at neutral medium. Lowering the pH of the supernatant to 2 resulted in the precipitation of lignocellulose. Thermal treatment of the biomass residue under N₂ gas stream resulted in activated carbon production. Separated products were dried/treated and characterized using several physical examination techniques, such as FT-IR, SEM/EDX, XRD, and Raman spectroscopy in order to study their structure and morphology. Silica and lignocelluloses products were then preliminarily used in the treatment of wastewaters and water-desalination processes.     

Aramid-wrapped CNT hybrid sol–gel sorbent for polycyclic aromatic hydrocarbons

This work describes the preparation of an analytical microextraction sorbent using a simple and versatile sol–gel hybrid composite, i.e., aramid oligomers wrapping multi-walled carbon nanotubes (CNTs) covalently bonded to a porous silica network. To overcome the inherent shortcomings of the CNTs'' solubility and dispersion in both organic phases and in the sol–gel solution, the outer surface of the CNTs was initially functionalized with carboxylic acid groups and then reacted with both aramid oligomers and 3-aminopropyl triethoxysilane (APTES). The obtained sorbent was characterized by FT-IR, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Using sol–gel chemistry, the functionalized CNTs were coated onto SPME fibers and used in conjunction with GC-MS for the analysis of polycyclic aromatic hydrocarbons (PAHs) in water and soil samples. Excellent repeatability (run-to-run RSD% ∼ 8) and reproducibility (fiber-to-fiber RSD% ∼ 6) were achieved in addition to low LODs (0.10–0.30 ng mL⁻¹) and noticeable recovery%. The present method of sorbent preparation led to enhanced thermal and chemical stabilities, a long sorbent lifetime and good affinity towards PAHs. Moreover, the present sorbent enhanced the extraction capability by more than 30% compared to that of commercially available PDMS counterparts.

This work describes the preparation of an analytical microextraction sorbent using a simple and versatile sol–gel hybrid composite, i.e., aramid oligomers wrapping multi-walled carbon nanotubes (CNTs) covalently bonded to a porous silica network.     

Dental arch changes after anterior open bite treatment in the mixed dentition produced by miniscrew-supported palatal crib vs conventional fixed palatal crib:: A randomized clinical trial

ObjectivesTo evaluate the dental arch changes produced by the miniscrew-supported palatal crib (MSPC) and the conventional fixed palatal crib (CFPC) after the treatment of patients with anterior open bite (AOB) attributed to the tongue-thrusting habit in the mixed dentition stage.Materials and MethodsA total of 26 children aged 8 to 11 years with an AOB were randomly distributed into two equal groups; the MSPC group was treated using a palatal crib supported by two miniscrews inserted paramedially, whereas the CFPC group was treated using a conventional fixed palatal crib soldered to bands. Digital models were obtained pretreatment and after a follow-up duration of 9 months.ResultsThe MSPC group included 12 participants (9 girls and 3 boys; mean age, 9.4 ± 0.75 years), and the CFPC group included 12 participants (10 girls and 2 boys; mean age, 9.0 ± 0.73 years). The amount of AOB closure was similar in both groups: 3.97 ± 1.44 mm in the MSPC group and 3.97 ± 0.89 mm in the CFPC group. There was significant mesial movement of the maxillary first molar in the CFPC (−1.42 ± 0.99 mm) compared with the MSPC group (−0.53 ± 0.32 mm).ConclusionsBoth appliances resulted in similar improvement in the amount of AOB closure. There was significantly more mesial movement of the maxillary first molars in the CFPC group compared with the MSPC group.     

Moyamoya syndrome presenting in an adult with Down syndrome: A case report with a literature review

Moyamoya disease is an unusual occlusive cerebrovascular condition commonly seen in children, marked by stenosis of the internal carotid artery and circle of Willis, causing, cerebral ischemia. Moyamoya syndrome is a Moyamoya-like arteriopathy with risk factors including autoimmune disorders, thyroid disease, sickle cell disease, or Down syndrome. Trisomy 21 is a genetic disorder consistent with specific physical and behavioral characteristics, with intellectual impairment. We describe a rare case of Moyamoya syndrome manifesting as ischemic stroke in an adult with Down syndrome