Synthesis and characterization of azaborepin radicals in solid neon through boron-mediated C-N bond cleavage of pyridine.

The reactivity of pyridine is a complex topic due to its unique electronic structure. The reactions of atomic boron with pyridine molecules in solid neon have been investigated using matrix isolation infrared absorption spectroscopy. Three products (marked as A, B, and C) were observed and characterized through 10B, D and 15N isotopic substitution pyridine regents as well as quantum chemical calculations. In the reaction, the ground-state boron atom can attack the lone pair electrons of the nitrogen atom in the pyridine molecule, resulting in the formation of a 1-boropyridinyl radical (A). Alternatively, addition to the aromatic π-system of pyridine can occur in a [1,4] type, leading to the formation of a B[η2(1,4)-C5H5N] complex (B). Under UV-visible light (280 < λ < 580 nm) irradiation, these two compounds can further undergo photo-isomerization to form BN-embedded seven-membered azaborepin compounds (C). The observation of species A, B, and the subsequent photo-isomerization to species C is consistent with theoretical predictions, indicating that these reactions are kinetically favorable. This research provides valuable insights into the future design and synthesis of corresponding BN heterocyclic derivatives.

Modification of regenerated cellulose ultrafiltration membranes with multi-walled carbon nanotubes for enhanced antifouling ability: Field test and mechanism study.

Although ultrafiltration (UF) has been extensively employed for drinking water purification, it is crucial to further develop novel membrane materials to improve the antifouling capacity and satisfy the practical usage. Multi-walled carbon nanotubes (MWCNTs) have characteristics that could potentially improve the membrane antifouling performance. Therefore, in this study, modified cellulose UF membranes were prepared using MWCNTs of various outer diameters ranging from 10 to 20 nm to 40-60 nm. The antifouling properties of the modified membrane and natural organic matter (NOM) removal mechanism were investigated while treating water from a local drinking water source river. Overall, the antifouling ability increased by more than one-fold when the nascent cellulose membrane was coated with MWCNTs (outer diameter of 40-60 nm) at a loading of 17.4 g/m2. The molecular weight distribution profiles of the NOM in the raw water and permeates suggest the superior performance of the modified membranes in removing two major NOM fractions with molecular weights ranging from approximately 5 k-30 k and 500 k-1000 k. Based on its hydrophobicity, the NOM of the raw water was fractionated into the strong hydrophobic (SHPO), the weak hydrophobic, the strong hydrophilic and the moderately hydrophilic (MHPI) fractions. The WHPO fraction caused the highest fouling compared with the other fractions under consistent experimental conditions. Meanwhile, the modified membranes showed a preference for removing the MHPI and SHPO fractions. These results imply that MWCNTs can be employed to improve the antifouling property of cellulose UF membranes and have the potential to selectively remove moderately hydrophilic contaminants from water.

Is it meaningful to distinguish between generalized and specific Internet addiction? Evidence from a cross-cultural study from Germany, Sweden, Taiwan and China.

INTRODUCTION: It has been hypothesized that two distinctive forms of Internet addiction exist. Here, generalized Internet addiction refers to the problematic use of the Internet covering a broad range of Internet-related activities. In contrast, specific forms of Internet addiction target the problematic use of distinct online activities such as excessive online video gaming or activities in social networks. METHODS: The present study investigates the relationship between generalized and specific Internet addiction in a cross-cultural study encompassing data from China, Taiwan, Sweden and Germany in n = 636 participants. In this study, we assessed - besides generalized Internet addiction - addictive behavior in the domains of online video gaming, online shopping, online social networks and online pornography. RESULTS: The results confirm the existence of distinct forms of specific Internet addiction. One exception, however, was established in five of the six samples under investigation: online social network addiction correlates in large amounts with generalized Internet addiction. DISCUSSION: In general, it is of importance to distinguish between generalized and specific Internet addiction.

The 2D:4D ratio of the hand and schizotypal personality traits in schizophrenia patients and healthy control persons.

Prenatal estrogen/testosterone exposure is known to be involved in early brain development. In this context, the ratio of the index finger to ring finger length (2D:4D) has been put forward as an indicator of the intrauterine sex hormonal level. A previous study by Collinson et al. (2010) examined 2D:4D ratios in Asian patients with schizophrenia and found an increased 2D:4D pattern in male patients compared to male healthy controls. In the current study, we tried to replicate the result of this study on the 2D:4D ratio in schizophrenia patients and controls in a Chinese sample. Moreover, we investigated the link between 2D:4D ratios and schizotypal personality traits in the participants of the study. No significant difference between cases and controls in 2D:4D ratios for both hands could be observed. However, a positive association between right 2D:4D ratio and schizotypal personality traits was found in healthy controls (both in the male and female subsamples) suggesting that a high 2D:4D ratio could represent a vulnerability factor for schizophrenia in healthy males and females. Same results were observed for the digit ratio of the left hand and the SPQ in the healthy total and healthy female subsample. Therefore, the inclusion of personality measures to study the link between the digit ratio and schizophrenia might help to provide insights in a potential continuum from healthy to schizophrenic behavior.