983 research outputs found
2-Amino-3-methylpyridinium 2-amino-5-methylpyridinium sulfate monohydrate
The asymmetric unit of the title compound, 2C6H9N2
+·SO4
2−·H2O, contains two isomeric protonated aminomethylpyridine cations, a sulfate anion and a solvent water molecule. The cations are in the iminium tautomeric form. In the crystal structure, intermolecular O—H⋯O, N—H⋯O and weak C—H⋯O hydrogen bonds link the components into a three-dimensional network. Additional stabilization is provided by weak π–π stacking interactions, with centroid–centroid distances of 3.758 (2) and 3.774 (1) Å
Bis(2-amino-6-methylpyridinium) tetrachloridocuprate(II)
The title compound, (C6H9N2)2[CuCl4], contains a distorted tetrahedral [CuCl4]2− anion and two protonated aminopyridinium cations. The geometries of the protonated aminopyridinium cations reveal amine–imine tautomerism. The crystal packing is influenced by N—H⋯Cl and C—H⋯Cl hydrogen bonds and π–π stacking interactions [centroid–centroid distances = 3.635 (4) and 3.642 (4)°]
CT呈现肋骨压迹的胸膜孤立性纤维性肿瘤1例分析
Objective: To explore the clinical and radiographic characteristics, methods of diagnosis and treatment of solitary fibrous tumor of the pleura (SFTP). Methods: To retrospectively analyze the diagnostic process of 1 case of SFT patients with computed tomography (CT) presenting rib impression, and to have literature review. Results: The patients had obvious clinical symptoms. His chest CT showed a 3.4cm×2.4cm size round soft tissue density in the right upper chest wall outside pleura, the boundary between pleura and the image is not clear, adjacent rib showed traces of impression formation, enhanced scanning lesions was slightly uneven, range small patchy low enhancement. His pathological examination showed that the tumor tissue is mainly composed of spindle cells, and immunohistochemis- try showed CD34, CD99, SMA positive. Conclusions: SFTP is a rare spindle cell tumor, clinical manifestation and imaging are not specific. The pressure trace CT presented is not proprietary features of neurogenic tumors in the ribs. The diagnosis of SFTP mainly depends on the pathological and immunohistochemistry examination. Operation is the first choice of the treatment, and prognosis is good after the operation.目的 探讨胸膜孤立性纤维性肿瘤(SFTP)的临床、影像学特征及诊治方法。方法 回顾性分析1例CT呈现肋骨压迹的胸膜SFT的诊断过程,并复习有关文献。结果 该患者无明显临床症状;胸部CT示右侧后上胸壁胸膜外见一个约3.4cm×2.4cm大小的类圆形软组织密度影,边界与胸膜分界不清,临近肋骨有压迹形成,增强扫描病灶强化稍不均匀,灶内可见小斑片状低强化影;病理检查示肿瘤组织主要由梭形细胞组成,免疫组织化学示CD34、CD99、SMA阳性。结论 SFTP是一种少见的梭形细胞肿瘤,临床表现及影像学检查无特异性,CT呈现肋骨压迹并非神经源性肿瘤的专有特征,诊断主要依靠病理及免疫组织化学检查,手术治疗是首选的治疗方法,术后预后较好
The Microsoft System for VoxCeleb Speaker Recognition Challenge 2022
In this report, we describe our submitted system for track 2 of the VoxCeleb
Speaker Recognition Challenge 2022 (VoxSRC-22). We fuse a variety of
good-performing models ranging from supervised models to self-supervised
learning(SSL) pre-trained models. The supervised models, trained using
VoxCeleb-2 dev data, consist of ECAPA-TDNN and Res2Net in a very deep
structure. The SSL pre-trained models, wav2vec and wavLM, are trained using
large scale unlabeled speech data up to million hours. These models are
cascaded with ECAPA-TDNN and further fine-tuned in a supervised fashion to
extract the speaker representations. All 13 models are applied with score
normalization and calibration and then fused into the the submitted system. We
also explore the audio quality measures in the calibration stage such as
duration, SNR, T60, and MOS. The best submitted system achieves 0.073 in minDCF
and 1.436% in EER on the VoxSRC-22 evaluation set.Comment: 3 pages, 3 tables, VoxSRC202
Sequence Characterization of the MC1R Gene in Yak (Poephagus grunniens) Breeds with Different Coat Colors
Melanocortin 1 receptor (MC1R) gene plays a key role in determining coat color in several species, including the cattle. However, up to now there is no report regarding the MC1R gene and the potential association of its mutations with coat colors in yak (Poephagus grunniens). In this study, we sequenced the encoding region of the MC1R gene in three yak breeds with completely white (Tianzhu breed) or black coat color (Jiulong and Maiwa breeds). The predicted coding region of the yak MC1R gene resulted of 954 bp, the same to that of the wild-type cattle sequence, with >99% identity. None of the mutation events reported in cattle was found. Comparing the yak obtained sequences, five nucleotide substitutions were detected, which defined three haplotypes (EY1, EY2, and EY3). Of the five mutations, two, characterizing the EY1 haplotype, were nonsynonymous substitutions (c.340C>A and c.871G>A) causing amino acid changes located in the first extracellular loop (p.Q114K) and in the seventh transmembrane region (p.A291T). In silico prediction might indicate a functional effect of the latter substitution. However, all three haplotypes were present in the three yak breeds with relatively consistent frequency distribution, despite of their distinguished coat colors, which suggested that there was no across-breed association between haplotypes or genotypes and black/white phenotypes, at least in the investigated breeds. Other genes may be involved in affecting coat color in the analyzed yaks
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