Structure and dynamics of the fullerene polymer Li4 C60 studied with neutron scattering

The two-dimensional polymer structure and lattice dynamics of the superionic conductor Li4 C60 are investigated by neutron diffraction and spectroscopy. The peculiar bonding architecture of this compound is definitely confirmed through the precise localisation of the carbon atoms involved in the intermolecular bonds. The spectral features of this phase are revealed through ab-initio lattice dynamics calculations and inelastic neutron scattering experiments. The neutron observables are found to be in very good agreement with the simulations which predict a partial charge transfer from the Li atoms to the C60 cage. The absence of a well defined band associated to one category of the Li atoms in the experimental spectrum suggests that this species is not ordered even at the lowest temperatures. The calculations predict an unstable Li sublattice at a temperature of 200 K, that we relate to the large ionic diffusivity of this system. This specificity is discussed in terms of coupling between the low frequency optic modes of the Li ions to the soft structure of the polymer.Comment: 29 pages, 13 Figure

Mott Transition in the A15 Phase of Cs3C60 : Absence of a Pseudogap and Charge Order

We present a detailed NMR study of the insulator-to-metal transition induced by an applied pressure p in the A15 phase of Cs3C60. We evidence that the insulating antiferromagnetic (AFM) and superconducting (SC) phases coexist only in a narrow p range. At fixed p, in the metallic state above the SC transition T-c, the Cs-133 and C-13 NMR spin-lattice relaxation data are seemingly governed by a pseudogaplike feature. We prove that this feature, also seen in the (CsNMR)-Cs-133 shift data, is rather a signature of the Mott transition which broadens and smears out progressively for increasing (p,T). The analysis of the variation of the quadrupole splitting nu(Q) of the Cs-133 NMR spectrum precludes any cell symmetry change at the Mott transition and only monitors a weak variation of the lattice parameter. These results open an opportunity to consider theoretically the Mott transition in a multiorbital three-dimensional system well beyond its critical point.Peer reviewe

Altering Murine Leukemia Virus Integration Through Disruption of the Integrase and BET Protein Family Interaction

We report alterations to the murine leukemia virus (MLV) integrase (IN) protein that successfully result in decreasing its integration frequency at transcription start sites and CpG islands, thereby reducing the potential for insertional activation. The host bromo and extraterminal (BET) proteins Brd2, 3 and 4 interact with the MLV IN protein primarily through the BET protein ET domain. Using solution NMR, protein interaction studies, and next generation sequencing, we showthat the C-terminal tail peptide region ofMLV IN is important for the interaction with BET proteins and that disruption of this interaction through truncation mutations affects the global targeting profile of MLV vectors. The use of the unstructured tails of gammaretroviral INs to direct association with complexes at active promoters parallels that used by histones and RNA polymerase II. Viruses bearingMLV IN C-terminal truncations can provide new avenues to improve the safety profile of gammaretroviral vectors for human gene therapy

A microscale protein NMR sample screening pipeline

As part of efforts to develop improved methods for NMR protein sample preparation and structure determination, the Northeast Structural Genomics Consortium (NESG) has implemented an NMR screening pipeline for protein target selection, construct optimization, and buffer optimization, incorporating efficient microscale NMR screening of proteins using a micro-cryoprobe. The process is feasible because the newest generation probe requires only small amounts of protein, typically 30–200 μg in 8–35 μl volume. Extensive automation has been made possible by the combination of database tools, mechanization of key process steps, and the use of a micro-cryoprobe that gives excellent data while requiring little optimization and manual setup. In this perspective, we describe the overall process used by the NESG for screening NMR samples as part of a sample optimization process, assessing optimal construct design and solution conditions, as well as for determining protein rotational correlation times in order to assess protein oligomerization states. Database infrastructure has been developed to allow for flexible implementation of new screening protocols and harvesting of the resulting output. The NESG micro NMR screening pipeline has also been used for detergent screening of membrane proteins. Descriptions of the individual steps in the NESG NMR sample design, production, and screening pipeline are presented in the format of a standard operating procedure

Epidemiology and management of primary spontaneous pneumothorax: a systematic review.

Primary spontaneous pneumothorax (PSP) is one of the most common thoracic diseases affecting adolescents and young adults. Despite the high incidence of PSP and the availability of several international guidelines for its diagnosis and treatment, a significant behavioural heterogeneity can be found among those management recommendations. A working group of the Italian Society of Thoracic Surgery summarized the best evidence available on PSP management with the methodological tool of a systematic review assessing the quality of previously published guidelines with the Appraisal of Guidelines for Research and Evaluation (AGREE) II. Concerning PSP physiopathology, the literature seems to be equally divided between those who support the hypothesis of a direct correlation between changes in atmospheric pressure and temperature and the incidence of PSP, so it is not currently possible to confirm or reject this theory with reasonable certainty. Regarding the choice between conservative treatment and chest drainage in the first episode, there is no evidence on whether one option is superior to the other. Video-assisted thoracic surgery represents the most common and preferred surgical approach. A primary surgical approach to patients with their first PSP seems to guarantee a lower recurrence rate than that of a primary approach consisting of a chest drainage positioning; conversely, the percentage of futile surgical interventions that would entail this aggressive attitude must be carefully evaluated. Surgical pleurodesis is recommended and frequently performed to limit recurrences; talc poudrage offers

Expert consensus on resection of chest wall tumors and chest wall reconstruction

Chest wall tumors are a relatively uncommon disease in clinical practice. Most of the published studies about chest wall tumors are usually single-center retrospective studies, involving few patients. Therefore, evidences regarding clinical conclusions about chest wall tumors are lacking, and some controversial issues have still to be agreed upon. In January 2019, 73 experts in thoracic surgery, plastic surgery, science, and engineering jointly released the Chinese Expert Consensus on Chest Wall Tumor Resection and Chest Wall Reconstruction (2018 edition). After that, numerous experts put forward new perspectives on some academic issues in this version of the consensus, pointing out the necessity to further discuss the points of contention. Thus, we conducted a survey through the administration of a questionnaire among 85 experts in the world. Consensus has been reached on some major points as follows. (I) Wide excision should be performed for desmoid tumor (DT) of chest wall. After excluding the distant metastasis by multi-disciplinary team, solitary sternal plasmacytoma can be treated with extensive resection and adjuvant radiotherapy. (II) Wide excision with above 2 cm margin distance should be attempted to obtain R0 resection margin for chest wall tumor unless the tumor involves vital organs or structures, including the great vessels, heart, trachea, joints, and spine. (III) For patients with chest wall tumors undergoing unplanned excision (UE) for the first time, it is necessary to carry out wide excision as soon as possible within 1-3 months following the previous surgery. (IV) Current Tumor Node Metastasis staging criteria (American Joint Committee on Cancer) of bone tumor and soft tissue sarcoma are not suitable for chest wall sarcomas. (V) It is necessary to use rigid implants for chest wall reconstruction once the maximum diameter of the chest wall defect exceeds 5 cm in adults and adolescents. (VI) For non-small cell lung cancer (NSCLC) invading the chest wall, wide excision with neoadjuvant and/or adjuvant therapy are recommended for patients with stage T3-4N0-1M0. As clear guidelines are lacking, these consensus statements on controversial issues on chest wall tumors and resection could possibly serve as further guidance in clinical practice during the upcoming years

Changing climate—changing pathogens: Toxoplasma gondii in North-Western Europe

In this review, we describe the effects of global climate change for one specific pathogen: the parasite Toxoplasma gondii. It is postulated that an increase of T. gondii prevalence in humans can occur in some regions of North-Western Europe as a result of changing environmental conditions. Such a change can be predicted by using Global Climate Change models. We have elaborated such a prediction for one scenario (SRES A1) by using one specific model (CCSR/NRIES) as an example. Next to environmental factors, also anthropogenic factors may contribute to increased prevalence of T. gondii in this region. In order to counter the potential severe consequences of a potential increase resulting from the combination of climatic and anthropogenic factors, there is an urgent need for the development of a human vaccine. Until a vaccine that offers complete protection is developed, the emphasis should be on treatment optimization and prevention