Identification of Shell Colour Pigments in Marine Snails Clanculus pharaonius and C. margaritarius (Trochoidea; Gastropoda)

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The self-organizing fractal theory as a universal discovery method: the phenomenon of life

A universal discovery method potentially applicable to all disciplines studying organizational phenomena has been developed. This method takes advantage of a new form of global symmetry, namely, scale-invariance of self-organizational dynamics of energy/matter at all levels of organizational hierarchy, from elementary particles through cells and organisms to the Universe as a whole. The method is based on an alternative conceptualization of physical reality postulating that the energy/matter comprising the Universe is far from equilibrium, that it exists as a flow, and that it develops via self-organization in accordance with the empirical laws of nonequilibrium thermodynamics. It is postulated that the energy/matter flowing through and comprising the Universe evolves as a multiscale, self-similar structure-process, i.e., as a self-organizing fractal. This means that certain organizational structures and processes are scale-invariant and are reproduced at all levels of the organizational hierarchy. Being a form of symmetry, scale-invariance naturally lends itself to a new discovery method that allows for the deduction of missing information by comparing scale-invariant organizational patterns across different levels of the organizational hierarchy

Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

5-​S-​Lipoylhydroxytyrosol, a Multidefense Antioxidant Featuring a Solvent-​Tunable Peroxyl Radical-​Scavenging 3-​Thio-​1,​2-​dihydroxybenzene Motif

5-​S-​Lipoylhydroxytyrosol (1)​, the parent member of a novel group of bioinspired multidefense antioxidants, is shown herein to exhibit potent peroxyl radical scavenging properties that are controlled in a solvent-​dependent manner by the sulfur center adjacent to the active o-​diphenol moiety. With respect to the parent hydroxytyrosol (HTy)​, 1 proved to be a more potent inhibitor of model autoxidn. processes in a polar solvent (acetonitrile)​, due to a lower susceptibility to the adverse effects of hydrogen bonding with the solvent. Detn. of O-​H bond dissocn. enthalpies (BDE) in t-​butanol by EPR radical equilibration technique consistently indicated a ca. 1.5 kcal​/mol lower value for 1 relative to HTy. In good agreement, DFT calcns. of the BDEOH using an explicit methanol mol. to mimic solvent effects predicted a 1.2 kcal​/mol lower value for 1 relative to HTy. Forcing the geometry of the -​S-​R group to coplanarity with the arom. ring resulted in a dramatic decrease in the computed BDEOH values suggesting a potentially higher activity than the ref. antioxidant α-​tocopherol, depending on geometrical constrains in microheterogeneous environments. These results point to sulfur substitution as an expedient tool to tailor the chain-​breaking antioxidant properties of catechol derivs. in a rational and predictable fashion

Oxidative polymerization of 5,6-dihydroxyindoles. Tracking the biosynthetic pathway to melanin pigments

The importance of the 5,6-dihydroxyindoles as intermediates in the biosynthesis of melanins, the black-to-brown pigments of human skin, hair and eyes, has been recognized since the beginning of the century. However, it is only during the last decade that several fundamental issues concerning the biosynthesis and oxidative polymerization of these metabolites have been brought to focus and clarified. Besides unveiling hitherto unknown facets of the reactivity of the 5,6-dihydroxyindole system, these advances have yielded unprecedented insights into the origin, structure and properties of melanin pigments, and have thrown new light on the possible functional significance of the indole melanogens that are produced and excreted by active epidermal melanocytes. It is the aim of the present report to provide an overview of the most significant achievements on the oxidation chemistry of 5,6-dihydroxyindoles gained at Naples and other laboratories, with highlights on those aspects of closer relevance to the biosynthesis of melanins and related processes

Nitric Oxide Mediates the Glutamate-dependent Pathway for Neurotransmission in Sepia officinalis Chromatophore Organs.

Chromatophore organs are complex and unique structures responsible for the variety of body coloration patterns used by cephalopods to communicate and camouflage. They are formed by a pigment-contg. cytoelastic sacculus, surrounded by muscle fibers directly innervated from the brain. Muscle contraction and relaxation are responsible for expansion and retraction of the pigment-contg. cell. Their functioning depends on glutamate and Phe-Met-Arg-Phe-NH2-related peptides, which induce fast and slow cell expansion, resp., and 5-hydroxytryptamine, which induces retraction. Apart from these three substances and acetylcholine, which acts presynaptically, no other neuroactive compds. have so far been found to be involved in the neuroregulation of chromatophore physiol., and the detailed signaling mechanisms are still little understood. Herein, we disclose the role of nitric oxide (NO) as mediator in one of the signaling pathways by which glutamate activates body patterning. NO and nitric-oxide synthase have been detected in pigment and muscle fibers of embryo, juvenile, and adult chromatophore organs from Sepia officinalis. NO-mediated Sepia chromatophore expansion operates at slower rate than glutamate and involves cGMP, cyclic ADP-ribose, and ryanodine receptor activation. These results demonstrate for the first time that NO is an important messenger in the long term maintenance of the body coloration patterns in Sepia