Ultrasound assisted one-pot synthesis of 12-aryl8,9,10,12-tetrahydrobenzo[a]xanthen-11-one derivatives using chlorosulphonic acid as a catalyst under solvent-free conditions

ABSTRACT A multi component condensation of β-naphthol, aromatic aldehydes and cyclic 1,3-dicarbonyl compounds in presence of Chlorosulphonic acid (ClSO 3 H) as a catalyst to furnish 12-Aryl -8,9,10,12-tetrahydrobenzo [a]xanthen-11-ones derivatives in good to excellent yields under ultrasound and solvent free conditions at ambient temperature is described. This is an efficient and environmentally benign methodology

GINGIVAL RECESSION IN RELATION TO MUCOGINGIVAL DEFORMITIES AND OTHER PREDISPOSING FACTORS AFFECT FEMALES IN LOWER ESTHETIC ZONE

Background: Gingival recession (GR) is one of the most common esthetic problems affecting the middle and older aged peoples.  GR can lead to many changes as root caries, hypersensitivity, erosions, abrasions, plaque retention and aesthetic dissatisfaction. This study aimed to evaluate the prevalence of gingival recession in relation to mucogingival deformities in lower esthetic zone. Methods: A cross-sectional study was done on a sample of 290 females. The participants were interviewed for personal habits and examined for intraoral distribution of gingival recession and its various predisposing factors.  Results: The prevalence of gingival recession in lower anterior teeth was 234, 80.69 %.Around half of the participants had Millers' class I GR (n=146, 49%), thin gingival phenotype (n=168, 56.9 %), mucosal and gingival labial frenum attachment(n=132, 44.7%, n=148, 50.2%). Most of the participants had a sufficient attached gingiva (n=246, 83.4%) and normal vestibular depth(n=278, 94.2%). GR were statistically significant with vestibular depth, gingival biotype and attached gingiva (P≤0.05). Conclusion: Gingival recession in lower aesthetics zone was high in females especially Miller class I gingival recession  due to thin gingival phenotypes. Most of Yemeni females have adequate attached gingiva, normal vestibular depth with a frequent mucosallabial frenum in lower anterior teeth.                         Peer Review History: Received: 1 September 2022; Revised: 28 September; Accepted: 6 November, Available online: 15 November 2022 Academic Editor:  Dr. A.A. Mgbahurike, University of Port Harcourt, Nigeria, [email protected] Received file:                             Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.5/10 Reviewers: Dr. Bilge Ahsen KARA, Ankara Gazi Mustafa Kemal Hospital, Turkey, [email protected] Dr. George Zhu, Tehran University of Medical Sciences, Tehran, Iran, [email protected] Similar Articles:   RISK FACTORS OF PERIODONTAL DISEASES AMONG YEMENI YOUNG DENTAL PATIENTS ORAL CANDIDA ALBICANS COLONIZATION RATE IN FIXED ORTHODONTICS PATIENTS PREVALENCE OF MALOCCLUSION AMONG YEMENI CHILDREN OF PRIMARY SCHOOL

Paleomagnetism and Ar-40/Ar-39 geochronology of Yemeni Oligocene volcanics: Implications for timing and duration of Afro-Arabian traps and geometry of the Oligocene paleomagnetic field

A combined paleomagnetic and Ar-40/Ar-39 study was carried out along eight stratigraphically overlapping sections in the Oligocene Afro-Arabian flood volcanic province in Yemen (73 sites). The composite section covers the entire volcanic stratigraphy in the sampling region and represents five polarity zones that are correlated to the geomagnetic polarity time scale based on Ar-40/Ar-39 ages from this and previous studies. The resulting magnetostratigraphy is similar to that of the conjugate margin in Ethiopia. The earliest basaltic volcanism took place in a reverse polarity chron that appears to correspond to C11r, while the massive rhyolitic ignimbrite eruptions correlated to ash layers in Oligocene Indian Ocean sediment 2700 km away from the Afro-Arabian traps, appear to have taken place during magnetochron C11n. The youngest ignimbrite was emplaced during magnetochron C9n. Both 40Ar/39Ar and paleornagnetic data suggest rapid < 1 Ma eruption of the basal basalt units and punctuated eruption of the upper silicic units over a duration potentially as long as 3 Ma with interspersed eruptive hiatuses. Eruption of the basal basalts may have preceded the Oi2 cooling event. The paleornagnetic pole lambda=74.2 degrees N, phi=249.1 degrees E (A95=3.6 degrees; N=48) is supported by a positive reversal test. Paleosecular variation, estimated as the angular standard deviation of the VGP distribution 14.2 degrees+2.3 degrees/-1.7 degrees, is close to expected, suggesting that the paleornagnetic pole represents a time-averaged field. The pole is in excellent accord with the paleornagnetic poles obtained from the Ethiopian part of the Afro-Arabian province, after closure of the Red Sea. By analyzing Afro-Arabian paleomagnetic data in conjunction with contemporaneous paleomagnetic poles available from different latitudes we argue that the Oligocene paleomagnetic field was dominated by the axial dipole with insignificant non-dipole field contributions

Volcanic stratigraphy of large-volume silicic pyroclastic eruptions during Oligocene Afro-Arabian flood volcanism in Yemen

A new stratigraphy for bimodal Oligocene flood volcanism that forms the volcanic plateau of northern Yemen is presented based on detailed field observations, petrography and geochemical correlations. The > 1 km thick volcanic pile is divided into three phases of volcanism: a main basaltic stage ( 31 to 29.7 Ma), a main silicic stage ( 29.7 to 29.5 Ma), and a stage of upper bimodal volcanism ( 29.5 to 27.7 Ma). Eight large-volume silicic pyroclastic eruptive units are traceable throughout northern Yemen, and some units can be correlated with silicic eruptive units in the Ethiopian Traps and to tephra layers in the Indian Ocean. The silicic units comprise pyroclastic density current and fall deposits and a caldera-collapse breccia, and they display textures that unequivocally identify them as primary pyroclastic deposits: basal vitrophyres, eutaxitic fabrics, glass shards, vitroclastic ash matrices and accretionary lapilli. Individual pyroclastic eruptions have preserved on-land volumes of up to similar to 850 km(3). The largest units have associated co-ignimbrite plume ash fall deposits with dispersal areas > 1 x 10(7) km(2) and estimated maximum total volumes of up to 5,000 km(3), which provide accurate and precisely dated marker horizons that can be used to link litho-, bio- and magnetostratigraphy studies. There is a marked change in eruption style of silicic units with time, from initial large-volume explosive pyroclastic eruptions producing ignimbrites and near-globally distributed tuffs, to smaller volume (< 50 km(3)) mixed effusive-explosive eruptions emplacing silicic lavas intercalated with tuffs and ignimbrites. Although eruption volumes decrease by an order of magnitude from the first stage to the last, eruption intervals within each phase remain broadly similar. These changes may reflect the initiation of continental rifting and the transition from pre-break-up thick, stable crust supporting large-volume magma chambers, to syn-rift actively thinning crust hosting small-volume magma chambers

Twelve novel HGD gene variants identified in 99 alkaptonuria patients: focus on ‘black bone disease’ in Italy

Alkaptonuria (AKU) is an autosomal recessive disorder caused by mutations in homogentisate-1,2-dioxygenase (HGD) gene leading to the deficiency of HGD enzyme activity. The DevelopAKUre project is underway to test nitisinone as a specific treatment to counteract this derangement of the phenylalanine-tyrosine catabolic pathway. We analysed DNA of 40 AKU patients enrolled for SONIA1, the first study in DevelopAKUre, and of 59 other AKU patients sent to our laboratory for molecular diagnostics. We identified 12 novel DNA variants: one was identified in patients from Brazil (c.557T>A), Slovakia (c.500C>T) and France (c.440T>C), three in patients from India (c.469+6T>C, c.650–85A>G, c.158G>A), and six in patients from Italy (c.742A>G, c.614G>A, c.1057A>C, c.752G>A, c.119A>C, c.926G>T). Thus, the total number of potential AKU-causing variants found in 380 patients reported in the HGD mutation database is now 129. Using mCSM and DUET, computational approaches based on the protein 3D structure, the novel missense variants are predicted to affect the activity of the enzyme by three mechanisms: decrease of stability of individual protomers, disruption of protomer-protomer interactions or modification of residues in the region of the active site. We also present an overview of AKU in Italy, where so far about 60 AKU cases are known and DNA analysis has been reported for 34 of them. In this rather small group, 26 different HGD variants affecting function were described, indicating rather high heterogeneity. Twelve of these variants seem to be specific for Italy