Nucleofugalities of neutral leaving groups in 80% aqueous acetonitrile

Nucleofugalites of tetrahydrothiophene, dimethyl sulfide and differently substituted pyridines in 80 % aqueous acetonitrile have been derived from the SN1 solvolysis rate constants of the corresponding X,Y-substituted benzhydryl derivatives (1–10). In sol-volysis of sulfonium ions in 80 % aqueous acetonitrile, where acetonitrile is a good cation solvator, the solvation of the reactant ground state is an important rate determining variable since the positive charge is almost entirely located on the leaving group. As a consequence, reaction rates of sulfonium ions are more sensitive to the substrate structure in 80 % aqueous acetonitrile than in pure and aqueous alcohols, which are less efficient as cation solvators. In solvolysis of pyridinium ions the solvation of the reactant ground state is less important, since the positive charge is considerably distributed between the carbon at the reaction center and the leaving group. In such cases the important rate determining variable is solvation of the transition state. Slower reactions of pyridinium sub-strates progress over later, carbocation-like transition states in which the solvation is more important, so those substrates solvolyze slightly faster in aqueous acetonitrile than in methanol (k80AN > kM). Faster reactions proceed over earlier TS in which the solvation is diminished, so those substrates solvolyze somewhat faster in methanol than in aqueous acetonitrile (k80AN < kM). This work is licensed under a Creative Commons Attribution 4.0 International License

Morfološke i hemodinamske karakteristike vertebralnih arterija kod muškaraca i žena

Introduction: Men and women differ in diameters and MBFVs in VAs. Aim: to compare morphology and hemodynamics of VAs between sexes. Patients and methods: We examined 155 subjects using a linear 7.5 MHz probe (Aloka Prosound SSD-5500). Measurements were obtained at the V2 segment of VAs. Criteria: VA diameter of 2-4mm, systolic MBFVs of 0.35-0.70m/s, normal resistance pattern. Investigated parameters: diameters of VAs, MBFVs in VAs, sum of VA diameters, sum of MBFVs in VAs, diameter of the narrower and wider VA, and age. Results: 68 men and 87 women; 88 with a dominant left VA (56% of men and 58% of woman), 11 (7%) showed no dominance. Group differences: men had both VAs wider, and a larger diameter of the “wider” VA. There were no differences in MBFVs between men and women. Conclusion: Left VA is dominant in both sexes. There was no difference in MBFVs among sexes. Men have a wider VA than women.Uvod: Muškarci i žene se razlikuju u promjerima i srednjim brzinama strujanja krvi (SBSK) u vertebralnim arterijama (VA). Cilj: usporediti morfologiju i hemodinamiku VA među spolovima. Ispitanici i metode: Pregledali smo 155 osoba upotrebom linearne sonde 7,5 mHz (Aloka Prosound SSD-5500). Mjerenja su vršena u V2 segmentu VA. Kriteriji: VA dijametar 2-4mm, sistoličke SBSK 0,35-0,70m/s, normalan otpor. Mjereni parametri: promjeri VA, SBSK u VA, ukupni promjeri VA, ukupne SBSK u VAs, promjeri “uže” i šire VA, i dob. Rezultati: 68 muškaraca i 87 žena; 88 dominantnih lijevih VA (56% muškaraca i 58% žena), 11 (7%) bez dominacije. Razlike među grupama: muškarci imaju šire obje VA i promjer “šire” VA. Nije bilo razlika u sbsk među spolovima. Zaključak: Lijeva VA je dominantna u oba spola, nema razlika u SBSK među spolovima. Muškarci imaju šire VA od žena

Cardiac masses – a sight to behold

Cardiac masses are an important and often impressive finding during echocardiography. Masses can be present in any cardiac cavity and they can cause functional obstruction to blood flow with serious consequences. The most common masses are thrombi, tumors and vegetations. While the definitive diagnosis is usually obtained from pathology report, with echocardiography we can establish the localization, size, mobility, echogenicity and the likely diagnosis. Vegetations are infectious masses, irregularly shaped, with a chaotic movement pattern and most commonly located on the upstream side of valve leaflets. Cardiac tumors can be primary or nonprimary, the latter ones being more common. Metastases to the heart are most frequently associated with melanoma, lung, breast or hematological neoplasms. Primary cardiac tumors are mostly benign but can cause significant obstruction to blood flow. Myxomas are the most common benign tumors, followed by papillary fibroelastomas. Primary malignant cardiac tumors are rare, and they include angiosarcomas, rhabdomyosarcomas, fibrosarcomas and mesotheliomas. Thrombi are masses associated with areas of limited blood flow – most commonly left ventricular aneurysms. Initial transthoracic echocardiography (TTE) in the evaluation of cardiac masses can be supplemented by 3D imaging, transesophageal echocardiography (TEE) and especially by contrast echocardiography. A comprehensive TTE/TEE examination paired with clinical information can reasonably suggest what type of mass is present.1-4 In our presentation we will discuss three patients with the three most common cardiac masses (tumor, thrombus and vegetation) and with different clinical outcomes. We will focus on the echocardiographic examination and the advantages of contrast echocardiography

Učestalost, vrsta i etiologija dentalnih i mekotkivnih ozljeda kod djece u Hrvatskoj

The prevalence, type and etiology of dental and soft tissue injuries and relationship between the time of arrival and sustaining soft tissue injury were analyzed in this retrospective study conducted at the Department of Pediatric Dentistry, University Dental Clinic in Zagreb, Croatia, during the 2010-2014 period using documentation on 447 patients (264 male and 183 female) aged 1-16 years with injuries of primary and permanent teeth. The highest prevalence of traumatic dental injury (TDI) was found in the 7-12 age group and maxillary central incisors were most frequently affected (80.9%) in both primary and permanent dentitions. Enamel-dentin fracture without pulp exposure (31.9%) was the most common TDI of dental hard tissue in both dentitions, whereas subluxation (27.3%) was the most common periodontal tissue injury type. The most frequent location, cause and seasonal variation of trauma were at home, falling and spring. Soft tissue injuries were observed in 203 (45.4%) patients. Soft tissue injuries were less likely when fewer teeth were traumatized (p<0.001). Comparison of children with and without soft tissue injuries yielded a statistically significant difference in the time to arrival between primary and permanent teeth (p<0.01). Because soft tissue injuries include bleeding and clinical presentation appears more dramatic, the time elapsed between injury and initial treatment was shorter than in non-bleeding injuries, pointing to the need of education focused on parents and school teachers regarding the importance of immediate therapy for both bleeding and non-bleeding TDIs.Svrha ovoga istraživanja je bila istražiti učestalost, vrstu i etiologiju dentalnih ozljeda te ozljeda mekih tkiva. Također se ispitala korelacija vremena proteklog između ozljede i potražene pomoći kada su bile prisutne i ozljede mekih tkiva. Retrospektivno istraživanje je provedeno na Zavodu za dječju stomatologiju Stomatološkog fakulteta Sveučilišta u Zagrebu u razdoblju od 2010. do 2014. godine koristeći dokumentaciju 447 pacijenata u dobi od 1-16 godina (264 dječaka i 183 djevojčice) s ozljedama mliječnih i trajnih zubi. Najveća učestalost traumatskih dentalnih ozljeda je pronađena u dobnoj skupini od 7 do 12 godina, a gornji središnji sjekutići (80,9%) su bili najčešće zahvaćeni zubi u obje denticije. Fraktura cakline i dentina bez izlaganja pulpe (31,9%) bila je najčešća vrsta ozljede kod tvrdog zubnog tkiva u obje denticije, dok je subluksacija (27,3%) bila najčešća vrsta ozljede parodontnog tkiva. Najčešća lokacija, uzrok i godišnje doba traume su bile kod kuće, pad i proljeće. Ozljede mekih tkiva su pronađene kod 203 (45,4%) pacijenata i bile su češće kod pacijenata koji su imali više traumom zahvaćenih zubi (p<0,001). Uspoređujući pacijente s ozljedama mekih tkiva i one bez njih statistički značajna razlika pronađena je u vremenu proteklom do potražene stručne pomoći između mliječnih i trajnih zuba (p<0,01). Zbog toga što ozljede mekih tkiva često uključuju krvarenje cijela klinička slika izgleda mnogo dramatičnije, vrijeme proteklo između ozljede i početnog liječenja bilo je kraće od onoga za ozljede koje nisu uključivale ozljedu mekih tkiva. To pokazuje potrebu za ciljanim obrazovanjem roditelja i učitelja o važnosti neposredne terapije dentalnih ozljeda kao i ozljeda mekih tkiva

Hipoplazija vertebralne arterije: značajke u uzorku hrvatske populacije

Vertebral arteries are responsible for 1/3 of the brain blood supply, supplying primarily posterior parts of the brain. About 15% of all strokes occur in posterior parts of the brain, which should be kept in mind when dealing with disorders that can cause hemodynamic changes in vertebral arteries. Vertebral artery hypoplasia (VAH) is an inborn abnormality of vertebral artery defined by smaller lumen diameter and lower blood flow velocities, and is most commonly found in healthy subjects. The aim of this study was to establish the characteristics of VAH in a Croatian population sample, and to determine differences in its presentation according to sex and affected side. Study results may prove valuable for future identification of individuals at an increased risk of cerebrovascular incidents or traumatic injuries that could lead to adverse changes of posterior circulation. Color Doppler flow imaging (CDFI) reports of 277 patients were analyzed. All measurements were obtained in the V2 segment of vertebral artery, between the C6-C5 vertebrae, using a linear 7.5 MHz probe on an Aloka Prosound SSD-5500. The criteria for normal vertebral arteries were lumen diameter of 2.5-4.5 mm, systolic mean blood flow velocity of 0.35-0.70 m/s, and normal resistance pattern. Study results showed the left vertebral artery to be dominant in 57% of study subjects, VAH to be more common in women, and right vertebral artery to be more often involved by hypoplasia than the left one. The width of the .wider. vertebral artery was greater in the group with VAH, suggesting a way of the deficit compensation. The study demonstrated that the deficit caused by VAH cannot be fully compensated for despite larger arterial diameter.Vertebralne arterije čine 30% krvne opskrbe mozga, opskrbljujući pretežito stražnje dijelove mozga. Petnaest posto svih moždanih udara nastaje u stražnjim dijelovima mozga, stoga je važno imati na umu značenje poremećaja koji uzrokuju hemodinamske promjene u vertebralnim arterijama. Hipoplazija vertebralne arterije je urođeno stanje koje obilježava uži lumen krvne žile i snižene srednje brzine strujanja krvi. Najčešće je prisutna kod zdravih pojedinaca. Cilj ovoga istraživanja bio je ustanoviti prisutnost i značenje hipoplazije vertebralne arterije u hrvatskoj populaciji, odrediti njenu pojavnost među spolovima i prema strani na kojoj se pojavljuje. Vjerovanja smo da je ovo istraživanje vrijedno zbog buduće lakše identifikacije pojedinaca izloženih većem riziku od nastanka cerebrovaskularnih poremećaja ili ozljeda koje mogu dovesti do problematičnih promjena u stražnjoj cirkulaciji. Analizirali smo nalaze 277 ispitanika. Sva mjerenja su izvedena u segmentu V2 vertebralne arterije, najčešće između vratnih kralježaka C6 i C5, upotrebom linearne sonde od 7,5 mHz na uređaju Aloka Prosound SSD¬5500. Kriteriji za uredan nalaz CDFI nad vertebralnim arterijama su: promjer vertebralne arterije od 2,5-4,5 mm, sistolične srednje brzine strujanja krvi od 0,35-0,70 m/s i zadovoljavajući cirkulacijski otpor u vertebralnim arterijama. Dobiveni rezultati su pokazali da je lijeva vertebralna arterija dominantna kod 57% ispitanika, hipoplazija vertebralne arterije češće zahvaća žene, a desna vertebralna arterija je češće hipoplastična od lijeve. Također, širina "šire" vertebralne arterije je veća kod ispitanika s hipoplazijom vertebralne arterije, što bi moglo upućivati na mehanizam kompenzacije deficita uzrokovanog hipoplazijom. Ovo istraživanje je pokazalo kako unatoč većoj širini nehipoplastične vertebralne arterije nije moguće u potpunosti nadoknaditi nedostatak uzrokovan hipoplazijom

The Prevalence of Lateral Incisor Hypodontia and Canine Impaction in Croatian Population

The study investigates the prevalence of second incisor hypodontia and canine impaction in Croatia. The study of incisor hypodontia encompassed 568 examinees (229 boys, 339 girls) aged 6–22 (X = 11.2, SD = 2.8) while for canine impaction, a subsample of 170 examinees older than 13 years was formed (68 boys and 102 girls). The participants were non-selected ambulatory patients of the Dental Clinic Zagreb and the School of Dental Medicine, University of Zagreb who voluntarily participated in the study. Investigated anomalies were registered from panoramic x-rays and dental records and a tooth was diagnosed as congenitally missing when no crown mineralization could be identified on dental panoramic tomogram and no evidence of extraction was found. For each examinee, the final dental panoramic tomogram evaluation was performed at the age of 13 years. Missing lateral incisors are found in 14 out of 568 participants, indicating the prevalence of 2.46%. With the M : F ratio 1 : 6, sex-specific prevalence are 0.87% and 3.54% for males and females respectively. The prevalence of missing lateral incisor is 1.76% in maxilla and 0.70% in mandible. The sex specific pattern as well as overall prevalence of lateral incisor hypodontia is within the range reported in other studies. On the other hand, the findings of bilaterally missing lateral incisor in six out of 14 examinees (or in 42.86% of hypodontia) is certainly the specificity of the here investigated population. The additional peculiarity is the finding of the bilateral aplasia of mandible canines registered in one child. Canine impaction is found in 8 participants of the present study (4.71%) and in all cases it was placed in maxilla. No sex specific differences in prevalence of impactions are found. In one case (or in 12.5%) a canine impaction is found bilaterally. Missing lateral incisors and canine impaction in the same examinee was not found in this study

Diterpenes and Phenolic Compounds from Salvia brachyodon Vandas

Salvia brachyodon, the short-tooth sage, is one of the rarest plant species and endemic in the Adriatic area of the Balkan Peninsula. As aside from its essential oil, only limited information on its phytochemical composition is known, a more detailed study of the leaves was undertaken. From its leaves two diterpenes, agastanol (2), and a new natural compound 1, i.e., 3-methyl-4-methylen-11,12,14-trihydroxy-8,11,13-abietatrien-7-one, were isolated and identified by NMR spectroscopy and mass spectrometry. In addition, caffeic acid, isoquercitrin, luteolin 7-O-glucoside and rosmarinic acid were identfied by comparison with reference compounds. The fraction containg the diterpenes as well as the isolated compound 1 showed significant antimycobacterial activity against Mycobacterium smegmatis. The diterpenes of S. brachyodon represent promising antimycobacterial substances for further evaluation. Due to the endangered nature of the plant, the wide use of S. brachyodon and its bioactive compounds could be achieved by growing the plants in culture