Magnetic Resonance Signal Amplification by Reversible Exchange of Selective PyFALGEA Oligopeptide Ligands Towards Epidermal Growth Factor Receptors

The biorelevant PyFALGEA oligopeptide ligand, which is selective towards the epidermal growth factor receptor (EGFR), has been successfully employed as a substrate in magnetic resonance signal amplification by reversible exchange (SABRE) experiments. It is demonstrated that PyFALGEA and the iridium catalyst IMes form a PyFALGEA:IMes molecular complex. The interaction between PyFALGEA:IMes and H₂ results in a ternary SABRE complex. Selective 1D EXSY experiments reveal that this complex is labile, which is an essential condition for successful hyperpolarization by SABRE. Polarization transfer from parahydrogen to PyFALGEA is observed leading to significant enhancement of the ¹H NMR signals of PyFALGEA. Different iridium catalysts and peptides are inspected to discuss the influence of their molecular structures on the efficiency of hyperpolarization. It is observed that PyFALGEA oligopeptide hyperpolarization is more efficient when an iridium catalyst with a sterically less demanding NHC ligand system such as IMesBn is employed. Experiments with shorter analogues of PyFALGEA, that is, PyLGEA and PyEA, show that the bulky phenylalanine from the PyFALGEA oligopeptide causes steric hindrance in the SABRE complex, which hampers hyperpolarization with IMes. Finally, a single-scan ¹H NMR SABRE experiment of PyFALGEA with IMesBn revealed a unique pattern of NMR lines in the hydride region, which can be treated as a fingerprint of this important oligopeptide.     

On the usefulness of guidelines and instructions for environmental assessment – a qualitative study of the helpfulness perceived by Polish practitioners

Guidelines and instructions for Environmental Impact Assessment and Strategic Environmental Assessment (together referred to as EA here) are developed to improve the quality of legal requirements’ implementation and to support EA procedure accomplishment. However, to date, it has not been checked whether they are useful for practitioners. Therefore, the aim of the study underlying this paper was to verify, based on the experience of Polish EA experts, whether guidelines and instructions are useful in their everyday work. A qualitative study comprising of a questionnaire survey and interviews tested whether (1) EA practitioners know and use the Polish and EU guidelines, (2) how EA practitioners evaluate the validity and usefulness of such instructions, and (3) in which areas there is a lack of instructions and guidelines. The results show a low level of knowledge of national and EU handbooks. Those guidelines focusing on legal procedures, road investments and designing animal passageways are considered to be the most useful. Moreover, practitioners indicate that EU guidelines should be translated into Polish. Most important for practitioners is the linking of guidelines with the EA procedure, so that they can become a platform for dialogue of all stakeholders.     

Correlation between the magnetic imaging of cobalt nanoconstrictions and their magnetoresistance response

Scanning transmission x-ray microscopy (STXM) and magnetoresistance (MR) measurements are used to investigate the magnetic behavior of a nanoconstriction joining two micrometric electrodes (a pad and a wire). The reversal of the magnetization under variable external static magnetic fields is imaged. By means of a detailed analysis of the STXM images at the nanocontact area, the MR is calculated, based on diffusive anisotropic-MR. This MR agrees well with that obtained from electrical transport measurements, allowing a direct correlation between the MR signal and the magnetic reversal of the system. The magnetization behavior depends on the sample thickness and constriction dimensions. In 40 nm-thick samples, with 20 × 175 nm(2) contact areas, the magnetization at the two sides of the constriction forms a net angle of 90°, with a progressive evolution of the magnetization structure between the electrodes during switching. The MR in those cases has a more peaked shape than with 20 nm-thick electrodes and 10 × 80 nm(2) contact areas, where the magnetization forms 180° between them, with a wide domain wall pinned at the constriction. As a consequence of this configuration, a plateau in the MR is observed for about 20 Oe.     

Determination of the surface diffusion coefficient and the residence time of adsorbates via local focused electron beam induced chemical vapour deposition

In this paper we present a model for local gas assisted focused electron beam induced deposition which allows estimating the surface diffusion coefficient and the residence time of volatile precursor adsorbates. Elaborating the existing continuum model for one adsorbate species and using a novel set of parameters we simplified the differential equation describing the dynamics of this process. We will show that stationary exposure experiments do not allow for a unique determination of the parameters residence time, surface diffusion coefficient, and net cross-section. Rather an estimation of parameter windows is possible by assuming meaningful values for the electron dissociation cross section. The model was applied to the experimental results for Cu(hfac)2 as a gas precursor.     

Leukaemias in BN/a and BN/b mice after prolonged treatment with antilymphocyte globulin

With the advent of direct coronary artery revascularization, the high mortality rate from cardiac disease associated with carotid endarterectomy can be favorably altered by simultaneous or staged revascularization for combined lesions. The choice for combined or sequential procedures is determined by the severity of the disease both clinically and anatomically in each system. Review of 32 patients with both severe coronary and carotid occlusive disease established that selective surgical intervention has been successful, with no deaths and only minimal morbidity. Simultaneous revascularization was carried out in 8 patients with preinfarctional angina, significant left main lesion or triple vessel disease producing a functional lesion of the left main coronary artery, and tight carotid lesion. Staged operations were performed in the remaining 24 patients. Priority of staging was determined by the extent of disease in each system.     

Ki-67 immunostaining and prognosis in laryngeal cancer

A 7-year-old male Husky dog developed atrophy of the right masseter muscle and pruritus of the right side of the face. A myogenic origin was excluded using muscular biopsy. Electrophysiologically, there was involvement of the motor and sensory fibers of the trigeminal nerve, suggesting a lesion located between the brainstem and the trigeminal ganglion. On MRI examination, a nodular mass was detected in the right caudal fossa. This mass was characterized by intense enhancement after injection of contrast medium. Because of the progressive clinical signs, electrophysiology, and MRI results, a presumptive diagnosis of a trigeminal nerve schwannoma was made. The animal's condition improved slightly with corticosteroids. The dog underwent euthanasia 3 months after initial presentation. Necropsy was not performed.     

基于场效应晶体管的太赫兹探测器中天线设计的一种有效方法

在场效应晶体管太赫兹探测器中,合理的天线设计可以增强晶体管和太赫兹波之间的耦合效率,从而提高太赫兹探测器的响应度.提出一种基于晶体管栅极边缘沟道电场的仿真来设计平面天线的方法.这种方法尤其适用于太赫兹波段晶体管输入阻抗不容易得到的情况.通过流片完成的基于氮化镓高电子迁移率晶体管的太赫兹探测器的响应度测试证实了这种方法的有效性.集成碟形天线和双偶极子天线的太赫兹探测器最大响应度分别在170.7 GHz(1568.4 V/W)和124.3 GHz(1047.2 V/W)频点处测得,这个测试结果接近基于晶体管栅极边缘沟道电场的仿真结果.