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Aircraft industry always looks for higher in-service temperatures and lighter structures. With a high specific strength, Ti-based alloys are good candidates for such applications. However, when exposed to oxidizing environments at high temperatures, they undergo large oxygen dissolution while forming an oxide scale, which can greatly affect their mechanical properties. Then, evaluating the oxidation resistance and mechanical behavior of such alloys is essential. In this aim, long term oxidation tests were performed under laboratory air between 500 °C and 625 °C on two Ti-based alloys: β21s, exhibiting a fully β microstructure supposed to dissolve lower amount of oxygen and nitrogen, and Ti6242S, with an α/β microstructure. The oxidized samples were characterized using XRD, Raman spectroscopy, SEM-EDS and micro-durometer. As for the mechanical behavior, tensile tests were performed at room temperature on not aged and on oxidized samples. While larger mass variations were obtained at 500 and 560 °C and up to 997 h at 625 °C for β21s, its mass variations became lower than those of Ti6242S for longer durations at 625 °C. Nevertheless, β21s exhibited thicker micro-hardness affected depths and underwent larger mechanical property modifications compared to Ti6242S.

Animal body plans are established during embryonic development by the Hox genes. This patterning process relies on the differential expression of Hox genes along the head-to-tail axis. Hox spatial collinearity refers to the relationship between the organization of Hox genes in clusters and the differential Hox expression, whereby the relative order of the Hox genes within a cluster mirrors the spatial sequence of expression in the developing embryo. In vertebrates, the cluster organization is also associated with the timing of Hox activation, which harmonizes Hox expression with the progressive emergence of axial tissues. Thereby, in vertebrates, Hox temporal collinearity is intimately linked to Hox spatial collinearity. Understanding the mechanisms contributing to Hox temporal and spatial collinearity is thus key to the comprehension of vertebrate patterning. Here, we provide an overview of the main discoveries pertaining to the mechanisms of Hox spatial-temporal collinearity., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

Ever since the discovery that the Hox family of transcription factors establish morphological diversity in the developing embryo, major efforts have been directed towards understanding Hox-dependent patterning. This has led to important discoveries, notably on the mechanisms underlying the collinear expression of Hox genes and Hox binding specificity. More recently, several studies have provided evidence that Hox factors have the capacity to bind their targets in an inaccessible chromatin context and trigger the switch to an accessible, transcriptional permissive, chromatin state. In this review, we provide an overview of the evidences supporting that Hox factors behave as pioneer factors and discuss the potential mechanisms implicated in Hox pioneer activity as well as the significance of this functional property in Hox-dependent patterning., Competing Interests: Conflicts of Interests The authors declare that they have no conflict of interest., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Developmental genes are frequently controlled by multiple enhancers sharing similar specificities. As a result, deletions of such regulatory elements have often failed to reveal their full function. Here, we use the Pitx1 testbed locus to characterize in detail the regulatory and cellular identity alterations following the deletion of one of its enhancers (Pen). By combining single cell transcriptomics and an in-embryo cell tracing approach, we observe an increased fraction of Pitx1 non/low-expressing cells and a decreased fraction of Pitx1 high-expressing cells. We find that the over-representation of Pitx1 non/low-expressing cells originates from a failure of the Pitx1 locus to coordinate enhancer activities and 3D chromatin changes. This locus mis-activation induces a localized heterochrony and a concurrent loss of irregular connective tissue, eventually leading to a clubfoot phenotype. This data suggests that, in some cases, redundant enhancers may be used to locally enforce a robust activation of their host regulatory landscapes., (© 2021. The Author(s).)

Reptiles exhibit a spectacular diversity of skin colors and patterns brought about by the interactions among three chromatophore types: black melanophores with melanin-packed melanosomes, red and yellow xanthophores with pteridine- and/or carotenoid-containing vesicles, and iridophores filled with light-reflecting platelets generating structural colors. Whereas the melanosome, the only color-producing endosome in mammals and birds, has been documented as a lysosome-related organelle, the maturation paths of xanthosomes and iridosomes are unknown. Here, we first use 10x Genomics linked-reads and optical mapping to assemble and annotate a nearly chromosome-quality genome of the corn snake Pantherophis guttatus The assembly is 1.71 Gb long, with an N50 of 16.8 Mb and L50 of 24. Second, we perform mapping-by-sequencing analyses and identify a 3.9-Mb genomic interval where the lavender variant resides. The lavender color morph in corn snakes is characterized by gray, rather than red, blotches on a pink, instead of orange, background. Third, our sequencing analyses reveal a single nucleotide polymorphism introducing a premature stop codon in the lysosomal trafficking regulator gene ( LYST ) that shortens the corresponding protein by 603 amino acids and removes evolutionary-conserved domains. Fourth, we use light and transmission electron microscopy comparative analyses of wild type versus lavender corn snakes and show that the color-producing endosomes of all chromatophores are substantially affected in the LYST mutant. Our work provides evidence characterizing xanthosomes in xanthophores and iridosomes in iridophores as lysosome-related organelles., Competing Interests: The authors declare no competing interest., (Copyright © 2020 the Author(s). Published by PNAS.)

Primary adenocarcinoma represent 0.5 to 2% of all bladder tumours and are classified according to whether or not they are derived from the urachus, although, histologically, this classification now appears to be obsolete. The authors report a very rare case of linitis plastica type of primary signet cell adenocarcinoma of the bladder in a 53-year-old patient. This carcinoma, with very unusual histological features, needs to be distinguished. Due to the delayed diagnosis, it has a poor prognosis despite the most aggressive treatment modalities, as reported in the literature. The elevated CA 19-9 observed in the present case may be a useful marker for follow-up.

A case of human dirofilariasis with Dirofilaria (Nochtiella) repens, located in a subcutaneous nodule of the arch of the foot is reported in a 64-year-old man living in the surroundings of Porto Vecchio in Corsica. The histological examination of this nodule has revealed a gravid female nematode, dead some weeks or months before its surgical excision. It is the second case of human dirofilariasis observed in a patient living on the island. The authors are surprised by the number of patients reported in medical literature (10 altogether) as having contracted the infection probably during a short stay in Corsica. This paper seeks to collect the fragmented available data on the existence in Corsica of nematodes in dogs and its possible vectors.

Objective: The incidental discovery of renal tumours is increasingly frequent. All small renal tumours are not inevitably cancers. The objective of our study was to compare radiological and histological data and to establish a diagnostic and therapeutic approach to the incidental discovery of a small renal tumour., Material and Methods: Retrospective study of 22 incidentally discovered asymptomatic renal tumours, with a long axis of less than 5 cm on the pathology specimen., Results: The tumour was discovered on ultrasound in 68% of cases. All patients were operated, allowing histological examination of the operative specimen, revealing 14 cancers, 4 angiomyolipomas, 2 adenomas and 2 haemorrhagic cysts (with thick contents). Ultrasound demonstrated a hypoechoic tumour in 13 cases, 11 of which were cancers, and a hyperechoic tumour in the other 7 cases, corresponding to 4 angiomyolipomas, 2 cancers, and 1 adenoma. Computed tomography showed a heterogeneous tumour in 12 cases, corresponding to a cancer in all but one case. The tumour was homogeneous in the other 10 cases, including 4 cancers. Arteriography showed a hypervascular tumour in 3 cases, all cancers, and a hypovascular tumour in 7 cases: 2 cancers, 2 adenomas, 2 very small angiomyolipomas and 1 haemorrhagic cyst., Conclusion: Despite the development of medical imaging, further progress is required to resolve the diagnostic problems raised by certain incidentally discovered asymptomatic renal tumours, particularly tumours with a homogeneous appearance on CT scan and a hypovascular appearance on arteriography.

The authors report an original case of acute myeloid leukaemia (AML) presenting in the form of acute urinary retention, confirmed by prostatic biopsy, with complete absence of any non-urological clinical features. Prostatic sites of leukaemia are frequent and classically reported, but often occur during the course of known leukaemia, and are rarely symptomatic, justifying biopsies in the presence of any prostatic symptoms. Immunolabelling represents the key to the diagnosis in the presence of undifferentiated cells demonstrated on prostatic biopsies. The outcome was fatal in this case, despite early chemotherapy. The clinical features, clinical course and therapeutic aspects of prostatic leukaemia are discussed.

A case of solitary benign neurofibroma of the recurrent laryngeal nerve is presented. The preoperative diagnosis was in favour of a thyroid cancer. The discovery of this benign tumour leads to discuss the malignancy criteria of a cold nodule. The recurrential paralysis is an evidence of malignancy in only about 80% of cases. The surgical operation is the best treatment because it allows the histology that asserts the benignancy of the lesion. The review of the literature confirms the exceptional nature of this tumour. The respective histology of neurofibromas is finally briefly recalled.

The authors report a case of infiltrating non-mucinous neuroendocrine breast tumor of both nesidioid and carcinoid type, exclusively composed of argyrophil cells and showing estrogen receptors. By comparing it to those published in literature, they conclude that there are two types of breast tumors with argyrophil cells: one very rare, exclusively composed of neuroendocrine cells, which may present all of the morphological, functional, evolutive aspects and particularly the carcinoid pattern of diffuse endocrine system tumors; the other is more common, composite, reminiscent according to the abundance of their neuroendocrine components, either of the features of diffuse endocrine system tumors, or of those of conventional adenocarcinomas. Their findings help to explain that the combined hormonoreceptive and hormonosecreting nature of these tumors is the particular property of their neuroendocrine cells comparable to that of the pituitary gland. In the composite tumors, these cells are associated in symbiosis with the epithelial glandular cells which are of ectodermal origin. Such an association, also observed in other parts of the body, is not fortuitous but functional and thus could contra-indicate antiestrogen hormonetherapy.