Activation of sp3-CH Bonds in a Mono(pentamethylcyclopentadienyl)yttrium Complex. X-ray Crystal Structures and Dynamic Behavior of Cp*Y(o-C6H4CH2NMe2)2 and Cp*Y[o-C6H4CH2NMe(CH2-μ)][μ-o-C6H4CH2NMe(CH2-μ)]YCp*[THF]

Reaction of Y(o-C6H4CH2NMe2)3 (1) with Cp*H gives Cp*Y(o-C6H4CH2NMe2)2 (2), which crystallizes in the monoclinic space group P21/n (No. 14) with a = 18.607 (4) Å, b = 15.633 (3) Å, c = 8.861 (3) Å, β = 102.73 (3)°, and Z = 4. Least-squares refinement with 3006 independent reflections (F > 4.0σ(F)) led to a final RF (wR) of 0.053 (0.068). The molecular structure consists of monomeric Cp*Y(o-C6H4CH2NMe2)2 units with a regularly bonded Cp* ligand (Y-Ct = 2.367 (3) Å), equal Y-C(aryl) distances (2.479 (6) and 2.471 (6) Å), and both nitrogen atoms coordinated to yttrium (Y-N distances = 2.568 (5) and 2.506 (6) Å). Short intramolecular Y···H distances (Y···H(181) = 3.00 (6) Å, Y···H(183) = 3.13 (9) Å) indicate agostic interactions. The long N(2)-C(18) bond (1.55 (1) Å) and the short Y···C(18) distance (3.202 (8) Å) indicate an Y···C-N agostic interaction. Thermolysis of 2 in THF gives Cp*Y[o-C6H4CH2NMe(CH2-μ)][μ-o-C6H4CH2NMe(CH2-μ)]YCp*[THF] (3) and N,N-dimethylbenzylamine. Compound 3 crystallizes in the monoclinic space group P21/c (No. 14) with a = 17.004 (1) Å, b = 13.962 (1) Å, c = 20.129 (3) Å, β = 92.94 (1)°, and Z = 4. Least-squares refinement with 4578 independent reflections (F > 5.0σ(F)) led to a final RF (wR) of 0.065 (0.070). The molecule consists of two Cp*Y fragments (Y(1)-Ct(1) = 2.420 (6) Å, Y(2)-Ct(2) = 2.414 (5) Å), bridged by two methylene carbon atoms (Y(1)-C(9) = 2.591 (10) Å, Y(2)-C(9) = 2.527 (9) Å, Y(1)-C(18) = 2.622 (10) Å, Y(2)-C(18) = 2.532 (10) Å) and one aryl carbon atom (Y(1)-C(1) = 2.702 (8) Å, Y(2)-C(1) = 2.547 (9) Å). The remaining aryl group is not bridging (Y(1)-C(10) = 2.441 (8) Å). Asymmetry in 3 is caused by THF coordination (Y(2)-O = 2.446 (5) Å). Thermolysis of 2 can be explained by dissociation of an Y-N dative bond followed by activation of an agostic C-H bond

Preverbs: an introduction

The notion ‘preverb’ is a traditional descriptive notion in Indo-European linguistics. It refers to morphemes that appear in front of a verb, and which form a close semantic unit with that verb. In many cases, the morpheme that functions as a preverb can also function without a preverbal context, often as an adverb or an adposition. Most linguists use the notion ‘preverb’ as a cover term for preverbal words and preverbal prefixes. The preverb may be separated from the verb whilst retaining its close cohesion with the verb, which is called ‘tmesis’. It may also develop into a bound morpheme, that is, a prefix inseparable from the verb, with concomitant reduction of phonological form in some cases. If the preverb has become a real prefix, we may use the more specific notion of ‘complex verb’, whereas we take the notion ‘complex predicate’ to refer generally to multi-morphemic expressions with verbal valency. That is, we make a terminological distinction between complex predicates and complex verbs. The latter are multi-morphemic, but behave as single grammatical words

Pubertal presentation in seven patients with congenital adrenal hyperplasia due to P450 Oxidoreductase deficiency

Context: P450 oxidoreductase (POR) is a crucial electron donor to all microsomal P450 cytochrome (CYP) enzymes including 17α-hydroxylase (CYP17A1), 21-hydroxylase (CYP21A2) and P450 aromatase. Mutant POR causes congenital adrenal hyperplasia with combined glucocorticoid and sex steroid deficiency. P450 oxidoreductase deficiency (ORD) commonly presents neonatally, with disordered sex development in both sexes, skeletal malformations, and glucocorticoid deficiency. \ud \ud Objective: The aim of the study was to describe the clinical and biochemical characteristics of ORD during puberty. \ud \ud Design: Clinical, biochemical, and genetic assessment of seven ORD patients (five females, two males) presenting during puberty was conducted. \ud \ud Results: Predominant findings in females were incomplete pubertal development (four of five) and large ovarian cysts (five of five) prone to spontaneous rupture, in some only resolving after combined treatment with estrogen/progestin, GnRH superagonists, and glucocorticoids. Pubertal development in the two boys was more mildly affected, with some spontaneous progression. Urinary steroid profiling revealed combined CYP17A1 and CYP21A2 deficiencies indicative of ORD in all patients; all but one failed to mount an appropriate cortisol response to ACTH stimulation indicative of adrenal insufficiency. Diagnosis of ORD was confirmed by direct sequencing, demonstrating disease-causing POR mutations. \ud \ud Conclusion: Delayed and disordered puberty can be the first sign leading to a diagnosis of ORD. Appropriate testosterone production during puberty in affected boys but manifest primary hypogonadism in girls with ORD may indicate that testicular steroidogenesis is less dependent on POR than adrenal and ovarian steroidogenesis. Ovarian cysts in pubertal girls may be driven not only by high gonadotropins but possibly also by impaired CYP51A1-mediated production of meiosis-activating sterols due to mutant POR

Neutral and Cationic Rare Earth Metal Alkyl and Benzyl Compounds with the 1,4,6-Trimethyl-6-pyrrolidin-1-yl-1,4-diazepane Ligand and Their Performance in the Catalytic Hydroamination/Cyclization of Aminoalkenes

A new neutral tridentate 1,4,6-trimethyl-6-pyrrolidin-1-yl-1,4-diazepane (L) was prepared. Reacting L with trialkyls M(CH2SiMe3)3(THF)2 (M = Sc, Y) and tribenzyls M(CH2Ph)3(THF)3 (M = Sc, La) yielded trialkyl complexes (L)M(CH2SiMe3)3 (M = Sc, 1; M = Y, 2) and tribenzyl complexes (L)M(CH2Ph)3 (M = Sc, 3; M = La, 4). Complexes 1 and 2 can be converted to their corresponding ionic compounds [(L)M(CH2SiMe3)2(THF)][B(C6H5)4] (M = Sc, Y) by reaction with [PhNMe2H][B(C6H5)4] in THF. Complexes 3 and 4 can be converted to cationic species [(L)M(CH2Ph)2]+ by reaction with [PhNMe2H][B(C6F5)4] in C6D5Br in the absence of THF. The neutral complexes 1-4 and their cationic derivatives were studied as catalysts for the hydroamination/cyclization of 2,2-diphenylpent-4-en-1-amine and N-methylpent-4-en-1-amine reference substrates and compared with ligand-free Sc, Y, and La neutral and cationic catalysts. The most effective catalysts in the series were the cationic L-yttrium catalyst (for 2,2-diphenylpent-4-en-1-amine) and the cationic lanthanum systems (for N-methylpent-4-en-1-amine). For the La catalysts, evidence was obtained for release of L from the metal during catalysis.

Rpgrip1 is required for rod outer segment development and ciliary protein trafficking in zebrafish

The authors would like to thank the Royal Society of London, the National Eye Research Centre, the Visual Research Trust, Fight for Sight, the W.H. Ross Foundation, the Rosetrees Trust, and the Glasgow Children’s Hospital Charity for supporting this work. This work was also supported by the Deanship of Scientific Research at King Saud University for funding this research (Research Project) grant number ‘RGP – VPP – 219’.Mutations in the RPGR-interacting protein 1 (RPGRIP1) gene cause recessive Leber congenital amaurosis (LCA), juvenile retinitis pigmentosa (RP) and cone-rod dystrophy. RPGRIP1 interacts with other retinal disease-causing proteins and has been proposed to have a role in ciliary protein transport; however, its function remains elusive. Here, we describe a new zebrafish model carrying a nonsense mutation in the rpgrip1 gene. Rpgrip1homozygous mutants do not form rod outer segments and display mislocalization of rhodopsin, suggesting a role for RPGRIP1 in rhodopsin-bearing vesicle trafficking. Furthermore, Rab8, the key regulator of rhodopsin ciliary trafficking, was mislocalized in photoreceptor cells of rpgrip1 mutants. The degeneration of rod cells is early onset, followed by the death of cone cells. These phenotypes are similar to that observed in LCA and juvenile RP patients. Our data indicate RPGRIP1 is necessary for rod outer segment development through regulating ciliary protein trafficking. The rpgrip1 mutant zebrafish may provide a platform for developing therapeutic treatments for RP patients.Publisher PDFPeer reviewe

Relationships between Serotonin Transporter Binding in the Raphe Nuclei, Basal Ganglia, and Hippocampus with Clinical Symptoms in Cervical Dystonia:A [C]DASB Positron Emission Tomography Study

PurposeAlterations of the central serotonergic system have been implicated in the pathophysiology of dystonia. In this molecular imaging study, we assessed whether altered presynaptic serotonin transporter (SERT) binding contributes to the pathophysiology of cervical dystonia (CD), concerning both motor and non-motor symptoms (NMS).MethodsWe assessed the non-displaceable binding potential (BPND) using the selective SERT tracer [11C]DASB and positron emission tomography (PET) in 14 CD patients and 12 age- and gender-matched controls. Severity of motor symptoms was scored using the Toronto Western Spasmodic Torticollis Rating Scale and Clinical Global Impression jerks/tremor scale. NMS for depressive symptoms, anxiety, fatigue, and sleep disturbances were assessed with quantitative rating scales. The relationship between SERT binding and clinical patient characteristics was analyzed with the Spearman’s rho test and multiple regression.ResultsWhen comparing the CD patients with controls, no significant differences in BPND were found. Higher BPND in the dorsal raphe nucleus was statistically significantly correlated (p < 0.001) with motor symptom severity (rs = 0.65), pain (rs = 0.73), and sleep disturbances (rs = 0.73), with motor symptom severity being the most important predictor of SERT binding. Furthermore, fatigue was negatively associated with the BPND in the medial raphe nucleus (rs = −0.61, p = 0.045), and sleep disorders were positively associated with the BPND in the caudate nucleus (rs = 0.58, p = 0.03) and the hippocampus (rs = 0.56, p = 0.02).ConclusionMotor symptoms, as well as pain, sleep disturbances, and fatigue in CD showed a significant relationship with SERT binding in the raphe nuclei. Moreover, fatigue showed a significant relationship with the medial raphe nucleus and sleep disorders with the caudate nucleus and hippocampus. These findings suggest that an altered serotonergic signaling in different brain areas in CD is related to different motor as well as NMS, which will further stimulate research on the role of serotonin in the pathogenesis of dystonia

A simple view of linguistic complexity

Although a growing number of second language acquisition (SLA) studies take linguistic complexity as a dependent variable, the term is still poorly defined and often used with different meanings, thus posing serious problems for research synthesis and knowledge accumulation. This article proposes a simple, coherent view of the construct, which is defined in a purely structural way, i.e. the complexity directly arising from the number of linguistic elements and their interrelationships. Issues of cognitive cost (difficulty) or developmental dynamics (acquisition) are explicitly excluded from this theoretical definition and its operationalization. The article discusses how the complexity of an interlanguage system can be assessed based on the limited samples SLA researchers usually work with. For the areas of morphology, syntax and the lexicon, some measures are proposed which are coherent with the purely structural view advocated, and issues related to their operationalization are critically scrutinized

No difference in striatal dopamine transporter availability between active smokers, ex-smokers and non-smokers using [123I]FP-CIT (DaTSCAN) and SPECT

Background: Mesolimbic and nigrostriatal dopaminergic pathways play important roles in both the rewarding and conditioning effects of drugs. The dopamine transporter (DAT) is of central importance in regulating dopaminergic neurotransmission and in particular in activating the striatal D2-like receptors. Molecular imaging studies of the relationship between DAT availability/dopamine synthesis capacity and active cigarette smoking have shown conflicting results. Through the collaboration between 13 SPECT centres located in 10 different European countries, a database of FP-CIT-binding in healthy controls was established. We used the database to test the hypothesis that striatal DAT availability is changed in active smokers compared to non-smokers and ex-smokers. Methods: A total of 129 healthy volunteers were included. Subjects were divided into three categories according to past and present tobacco smoking: (1) non-smokers (n = 64), (2) ex-smokers (n = 39) and (3) active smokers (n = 26). For imaging of the DAT availability, we used [123I]FP-CIT (DaTSCAN) and single photon emission computed tomography (SPECT). Data were collected in collaboration between 13 SPECT centres located in 10 different European countries. The striatal measure of DAT availability was analyzed in a multiple regression model with age, SPECT centre and smoking as predictor. Results: There was no statistically significant difference in DAT availability between the groups of active smokers, ex-smokers and non-smokers (p = 0.34). Further, we could not demonstrate a significant association between striatal DAT and the number of cigarettes per day or total lifetime cigarette packages in smokers and ex-smokers. Conclusion: Our results do not support the hypothesis that large differences in striatal DAT availability are present in smokers compared to ex-smokers and healthy volunteers with no history of smoking

Hubungan Antara Perhatian Orangtua Dan Hasil Belajar Pada Pembelajaran Tematik Integratif Siswa Kelas IV SD Negeri Kembangarum 2 Mranggen Demak

More less the studying result of students in 4th SD Negeri Kembangarum 2 Mranggen that influences some aspects, one of aspects is her parents?óÔé¼Ôäó not careless with them. Parents?óÔé¼Ôäó is constitute the?é?á first educator for children so that her parents?óÔé¼Ôäó has have responsibility to the studying result her children. The problem in this research contents is about Is there any correlation between of parents?óÔé¼Ôäó attention and the study result for thematic integrative learning in 4th SD Negeri Kembangarum 2 Mranggen Demak?. The hypothesis is that there is positive and significant correlation between of parents?óÔé¼Ôäó attention and the study result for thematic integrative learning in 4th SD Negeri Kembangarum 2 Mranggen Demak. The kind of this research is quantitative research. This research use correlation methode and submited the data use questionnaire and test. The colected data are analysed using product moment formula. The finding is that > on significancy level of 0,05. So the?é?á conclusion is there is positive and significant correlation between of parents?óÔé¼Ôäó attention and the study result for thematic integrative learning in 4th SD Negeri Kembangarum 2 Mranggen Demak