Silicene growth on Ag(110) and Ag(111) substrates reconsidered in light of Si-Ag reactivity.

Silicene, the 2D silicon allotrope analogue of graphene, was theoretically predicted in 1994 as a metastable buckled honeycomb silicon monolayer. Similarly to its carbon counterpart it was predicted to present an electronic structure hosting Dirac cones. In the last decade a great deal of work has been done to synthesize silicene and exploit its properties. In this paper we will review our research group activity in the field, dealing in particular with silicon-substrate interaction upon silicon deposition, and discuss the still debated silicene formation starting from the chemistry of silicon unsaturated compounds.

Evidence of ß-antimonene at the Sb/Bi2Se3 interface.

We report a study of the interface between antimony and the prototypical topological insulator Bi2Se3. Scanning tunnelling microscopy measurements show the presence of ordered domains displaying a perfect lattice match with bismuth selenide. Density functional theory calculations of the most stable atomic configurations demonstrate that the ordered domains can be attributed to stacks of ß-antimonene.

Making Informed Choices On Incorporating Chemoprevention into carE (MiCHOICE, SWOG 1904): Design and methods of a cluster randomized controlled trial.

INTRODUCTION: Women with atypical hyperplasia (AH) or lobular carcinoma in situ (LCIS) have a significantly increased risk of breast cancer, which can be substantially reduced with antiestrogen therapy for chemoprevention. However, antiestrogen therapy for breast cancer risk reduction remains underutilized. Improving knowledge about breast cancer risk and chemoprevention among high-risk patients and their healthcare providers may enhance informed decision-making about this critical breast cancer risk reduction strategy. METHODS/DESIGN: We are conducting a cluster randomized controlled trial to evaluate the effectiveness and implementation of patient and provider decision support tools to improve informed choice about chemoprevention among women with AH or LCIS. We have cluster randomized 26 sites across the U.S. through the SWOG Cancer Research Network. A total of 415 patients and 200 healthcare providers are being recruited. They are assigned to standard educational materials alone or combined with the web-based decision support tools. Patient-reported and clinical outcomes are assessed at baseline, after a follow-up visit at 6 months, and yearly for 5 years. The primary outcome is chemoprevention informed choice after the follow-up visit. Secondary endpoints include other patient-reported outcomes, such as chemoprevention knowledge, decision conflict and regret, and self-reported chemoprevention usage. Barriers and facilitators to implementing decision support into clinic workflow are assessed through patient and provider interviews at baseline and mid-implementation. RESULTS/DISCUSSION: With this hybrid effectiveness/implementation study, we seek to evaluate if a multi-level intervention effectively promotes informed decision-making about chemoprevention and provide valuable insights on how the intervention is implemented in U.S. TRIAL REGISTRATION: NCT04496739.

Discrepancies between tumor genomic profiling and germline genetic testing.

BACKGROUND: Tumor genomic profiling (TGP) often incidentally identifies germline pathogenic variants (PVs) associated with cancer predisposition syndromes. Methods used by somatic testing laboratories, including germline analysis, differ from designated germline laboratories that have optimized the identification of germline PVs. This study evaluated discrepancies between somatic and germline testing results, and their impact on patients. PATIENTS AND METHODS: Chart reviews were carried out at a single institution for patients who had both somatic and designated germline genetic testing. Cases with discrepant results in which germline PVs were not detected by the somatic laboratory or in which variant classification differed are summarized. RESULTS: TGP was carried out on 2811 cancer patients, 600 of whom also underwent designated germline genetic testing. Germline PVs were identified for 109 individuals. Discrepancies between germline genetic testing and tumor profiling reports were identified in 20 cases, including 14 PVs identified by designated germline genetic testing laboratories that were not reported by somatic testing laboratories and six variants with discrepant classifications between the designated germline and somatic testing laboratories. Three PVs identified by designated germline laboratories are targets for poly adenosine diphosphate-ribose polymerase (PARP) inhibitors and resulted in different treatment options. Of the PVs identified by designated germline laboratories, 60% (n = 12) were in genes with established associations to the patients' cancer, and 40% of the PVs were incidental. The majority (90%) of all discrepant findings, both contributory and incidental, changed management recommendations for these patients, highlighting the importance of comprehensive germline assessment. CONCLUSIONS: Methods used by somatic laboratories, regardless of the inclusion of germline analysis, differ from those of designated germline laboratories for identifying germline PVs. Unrecognized germline PVs may harm patients by missing hereditary syndromes and targeted therapy opportunities (e.g. anti-programmed cell death protein 1 immunotherapy, PARP inhibitors). Clinicians should refer patients who meet the criteria for genetic evaluation regardless of somatic testing outcomes.

Chirality transfer from a single chiral molecule to 2D superstructures in alaninol on the Cu(100) surface.

The formation of 2D chiral monolayers obtained by self-assembly of chiral molecules on surfaces has been widely reported in the literature. Control of chirality transfer from a single molecule to surface superstructures is a challenging and important aspect for tailoring the properties of 2D nanostructures. However, despite the wealth of investigations performed in recent years, how chiral transfer takes place on a large scale still remains an open question. In this paper we report a coupling of scanning tunneling microscopy and low energy electron diffraction measurements with an original theoretical approach, combining molecular dynamics and essential dynamics with density functional theory, to investigate self-assembled chiral structures formed when alaninol adsorbs on Cu(100). The peculiarity of this system is related to the formation of tetrameric molecular structures which constitute the building blocks of the self-assembled chiral monolayer. Such characteristics make alaninol/Cu(100) a good candidate to reveal chiral expression changes. We find that the deposition of alaninol enantiomers results in the formation of isolated tetramers that are aligned along the directions of the substrate at low coverage or when geometrical confinement prevents long-range order. Conversely, a rotation of 14° with respect to the Cu(100) unit vectors is observed when small clusters of tetramers are formed. An insight to the process leading to a 2D globally chiral surface has been obtained by monitoring molecular assemblies as they grow from the early stages of adsorption, suggesting that the distinctive orientation of the self-assembled monolayer originates from a balance of cooperating forces which start acting only when tetramers pack together to form small clusters.

Topologization of ß-antimonene on Bi2Se3 via proximity effects.

Topological surface states usually emerge at the boundary between a topological and a conventional insulator. Their precise physical character and spatial localization depend on the complex interplay between the chemical, structural and electronic properties of the two insulators in contact. Using a lattice-matched heterointerface of single and double bilayers of ß-antimonene and bismuth selenide, we perform a comprehensive experimental and theoretical study of the chiral surface states by means of microscopy and spectroscopic measurements complemented by first-principles calculations. We demonstrate that, although ß-antimonene is a trivial insulator in its free-standing form, it inherits the unique symmetry-protected spin texture from the substrate via a proximity effect that induces outward migration of the topological state. This "topologization" of ß-antimonene is found to be driven by the hybridization of the bands from either side of the interface.

Signature of surface periodicity in the electronic structure of Si(1 1 1)-(7 × 7).

The surface electronic structure of Si(1 1 1)-[Formula: see text] has been studied by angle-resolved photo electron spectroscopy. Replicas of the S 1 surface state are found in correspondence with several [Formula: see text] unit cells in the reciprocal space. This observation resolves in a direct way the long-standing dichotomy between the structural and electronic properties of the system previously discussed on the basis of the [Formula: see text] or [Formula: see text] R30° surface models.

Effects of chloride on the kinetics and stereochemistry of chloroperoxidase catalyzed oxidation of sulfides.

At pH 3, chloride dramatically influenced both the Km of chloroperoxidase (CPO) for methyl p-tolyl sulfide, which decreased, and its activity, which increased. The Km value changed from 75 microM in the absence of chloride to < or = 1.2 microM in > or = 0.9 mM chloride, and the kcat from 53 s-1 in 0 to 1750 s-1 in 50 mM halide. The kcat/Km value at 0.9 mM chloride was 414 microM -1s-1 compared to 0.7 microM-1s-1 in the absence of the halide. At pH 5, the activating effect was less pronounced. Chloride also acted as inhibitor versus hydrogen peroxide. The data are consistent with a reaction mechanism in which, on hand, chloride competes with hydrogen peroxide for the native enzyme and, on the other hand, activates sulfide oxidation by binding to CPO Compound I to give a CPO-chlorinating intermediate (EOCl-). However, contrary to what happened in the absence of chloride, where the oxidation was enantioselective and an oxygen atom of H2O2 was incorporated in the sulfoxide (from experiments with 18O-labeled H2O2), in the presence of the halide the oxidation was not enantioselective and there was no incorporation of oxygen from H2O2. The data suggest that sulfide oxidation takes place through an enzyme-generated freely dissociable oxidized halogen intermediate formed by the interaction of EOCl- with Cl-.

Recent biotechnological developments in the use of peroxidases.

Peroxidases are ubiquitous oxidoreductases that use hydrogen peroxide or alkyl peroxides as oxidants. Advances have recently been made in using them to prepare, under mild and controlled conditions, chiral organic molecules that are valuable for the chemoenzymatic synthesis of a wide range of useful compounds. Horseradish peroxidase can be converted into a peroxygenative enzyme by molecular engineering. Chloroperoxidase, the most versatile peroxidase, behaves like a 'true' monooxygenase in sulfoxidations with molecular oxygen and an external reductant, with substantial increases in enantioselectivity and enzyme stability.

Endothelin-1[1-31]: a novel autocrine-paracrine regulator of human adrenal cortex secretion and growth.

Endothelin (ET)-1[1-21] stimulates steroid secretion and zona glomerulosa growth and is expressed in the human and rat adrenal cortex together with its receptor subtypes A and B (ETA and ETB). Although ET-1[1-21] is generated from bigET-1 by an ET-converting enzyme (ECE-1), there is evidence of an alternative chymase-mediated biosynthetic pathway leading to the production of an ET-1[1-31] peptide, the role of which in adrenal pathophysiology is largely unknown. Gene expression and immunohistochemical studies allowed localization of chymase in the normal human adrenal cortex. Sizable amounts, not only of ET-1[1-21] but also of ET-1[1-31], were found in the adrenal vein plasma of three patients. ET-1[1-21] and ET-1[1-31] elicited a clear-cut secretory response by dispersed human adrenocortical cells, ET-1[1-31] being significantly less potent than ET-1[1-21]. The secretagogue effect of ET-1[1-31] was abolished by the ETA receptor antagonist BQ-123 and was unaffected by the ETB receptor antagonist BQ-788. Because, in humans, the secretagogue effect of ET-1[1-21] involves both ETA and ETB receptors, the weaker action of ET-1[1-31] could be attributable to a selective ETA receptor activation. Two lines of evidence support this contention: 1) ET-1[1-31] was more effective than ET-1[1-21] in stimulating ETA-mediated cell proliferation of human adrenocortical cells cultured in vitro; and 2) autoradiography showed that a) ET-1[1-31] displaced in vitro [(125)I]ET-1[1-21] binding to the ETA, but not ETB receptors, in human internal thoracic artery rings; and b) BQ-123, but not BQ-788, eliminated [(125)I]ET-1[1-31] binding in the rat adrenal cortex.

Cutaneous melanoma and sunburns in childhood in a southern European population.

A population-based case-control study of 260 patients (74 males and 186 females, mean age = 56) with cutaneous malignant melanoma and 416 controls (211 males and 205 females, mean age = 55) was conducted in Turin, north-west Italy, to examine the relation between timing of sunburns and sun exposure and melanoma risk within a southern European population, which is still relatively little investigated. Particularly elevated risk was associated with history of sunburns in childhood [odds ratio 5.9; 95% confidence interval (CI) 3.6-9.5], and such risk elevation persisted after allowance for other major melanoma risk covariates. Conversely, risk increase from history of severe sunburns lifelong was lower (odds ratio = 1.7; 95% CI: 1.1-2.4) and was eliminated by allowance for type of skin reaction to sun exposure and history of sunburns in childhood. A significant increase in the risk of cutaneous malignant melanoma was also associated with number of weeks spent on holiday at the beach not only as an adult, but also as a child.

Cutaneous malignant melanoma in females: the role of hormonal and reproductive factors.

The role of hormonal and reproductive factors as risks for cutaneous malignant melanoma (CMM) was explored by means of a population-based case-control study conducted in Turin, north-western Italy, on 186 female CMM cases and 205 controls. Past use of oral contraceptives (OC) did not seem to exert any effect on CMM risk odds ratio (OR) = 1.12, 95% confidence interval (CI): 0.56-2.24). No association was found even for the longest duration of use, for superficial spreading melanoma cases and for CMM of lower limbs only. While age at first birth did not affect CMM risk, women who had had three or more children seemed to be significantly protected as compared to nulliparous ones. The association was, however, substantially diminished by adjustment for education and other CMM risk correlates (OR for at least three children versus none = 0.62; 95% Cl: 0.29-1.31).

Chloroperoxidase-catalyzed enantioselective oxidation of methyl phenyl sulfide with dihydroxyfumaric acid/oxygen or ascorbic acid/oxygen as oxidants.

The chloroperoxidase catalyzed oxidation of methyl phenyl sulfide to (R)-methyl phenyl sulfoxide was investigated, both in batch and membrane reactors, using as oxidant H2O2, or O2 in the presence of either dihydroxyfumaric acid or ascorbic acid. The effects of pH and nature and concentration of the oxidants on the selectivity, stability, and productivity of the enzyme were evaluated. The highest selectivity was displayed by ascorbic acid/O2, even though the activity of chloroperoxidase with this system was lower than that obtained with the others. When the reaction was carried out in a membrane reactor, it was possible to reuse the enzyme for several conversion cycles. The results obtained with ascorbic acid/O2 and dihydroxyfumaric acid/O2 as oxidants do not seem to be compatible with either a mechanism involving hydroxyl radicals as the active species or with the hypothesis that oxidation occurs through the initial formation of H2O2. Copyright 1999 John Wiley & Sons, Inc.

Therapy for metastatic melanoma: effective combination of dacarbazine, carmustine, cisplatin and tamoxifen.

Thirty-two patients with metastatic melanoma received combination chemotherapy and hormonal therapy. Treatment included Carmustine, Cisplatin, Dacarbazine and Tamoxifen (BCDT). The overall response rate was 47%: five patients had a complete response (16%), 10 patients had a partial response (31%) and two had no response (6%). The median survival for responders was 10 months (range 2-20). The BCDT regimen was equally effective against soft tissue and visceral metastases. Neither survival or response rate was modified by pretreatment with alpha-interferon (alpha-IFN). In agreement with the results of a recent randomized trial comparing the efficacy of Dacarbazine with that of Dacarbazine plus Tamoxifen, a better survival was found in women than in men: although the response rate was identical (47%), the median duration of response was higher for women. A fall in serum soluble IL-2 receptor (sIL-2R) levels after therapy was seen in responding patients, confirming the usefulness of this parameter in monitoring disease evolution.

Low-dose integrated chemoimmuno-hormonotherapy with cisplatin, subcutaneous interleukin-2, alpha-interferon and tamoxifen for advanced metastatic melanoma--a pilot study.

Recently, Khayat et al. reported that high-dose recombinant interleukin-2 (rIL-2) i.v. may induce tumour regressions in metastatic melanoma patients through an association with cisplatin (CDDP) and alpha-interferon (alpha-IFN). Treatment-related toxicities are, however, important. Previous studies have demonstrated that rIL-2 toxicity may be reduced through a subcutaneous injection. In order to evaluate the effectiveness of low subcutaneous rIL-2 doses in a chemoimmuno-hormonotherapeutic combination, 36 metastatic melanoma patients were treated with CDDP, rIL-2, alpha-IFN and tamoxifen (TAM). The overall response rate was 47.2%: five patients had complete response (14%), 12 partial response (33%) and 13 stable disease (36%). Median response duration was 6.4 months (range: 2-29+). Median overall survival was 10 months (range: 3-36+). The CDDP/rIL-2/alpha-IFN/TAM regimen was effective both on soft tissue and visceral metastases. Toxicity was low and patient management did not require an intensive care unit. A statistically significant increase in both percentage and absolute values of lymphocytes, eosinophils, CD3+/CD4+, CD25+, CD16/56+ and HLA-DR+ cells was found in all patients after two treatment courses. This study shows that lower doses of subcutaneous rIL-2, as well as CDDP and alpha-IFN, associated with TAM, may have similar anticancer efficacy with respect to Khayat's schedule but lower toxicity.

Curved optics for x-ray phase contrast imaging by synchrotron radiation.

Conventional radiographic techniques have strong limitations when low-absorption contrast samples are imaged. Phase contrast radiography has been shown to produce high-quality images of soft tissues. In this technique the recorded intensity patterns are related to gradients in the refractive index of the sample. A critical point of this new technique is the need to employ crystal analysers, which results in an appreciable reduction in the beam intensity and consequently in rather long exposure times. In this paper the use of focused beams is suggested to overcome this aspect. Biological samples with small structures and low absorption variations were imaged using both flat and curved monochromator crystals, demonstrating that the use of curved optics leads to a decrease in the exposure time with only a limited degradation of the spatial resolution. This opens up the possibility of using the phase contrast technique with laboratory sources.

Ultrasonic vocalization in rat pups as a marker of behavioral development: an investigation of the effects of drugs influencing brain opioid system.

Early postnatal exposure to morphine significantly influenced the ultrasonic vocalization of rat pups removed from their nest. In particular, a significant decrease in the rate of calling, sound pressure level and range of frequency was found in morphine-treated animals; moreover, the duration of calls was significantly increased by morphine administration. Conversely, neither beta-casomorphins (beta CMS), which are opioid peptides derived from the enzymatic digestion of milk protein (beta-casein), nor an opioid antagonist, like naloxone, significantly affected ultrasonic emission. The results are discussed with particular reference to the role of the opioid system in separation distress-induced vocalization in young animals.

[Hyperbaric oxygen therapy in thrombotic occlusion of the central retinal vein]. / L'ossigenoterapia iperbarica nell'occlusione trombotica della vena centrale della retina.

The thrombosis of the retina's central vein is a monocular disease and generally touches old women. It causes failure of the sight and lessening of vision field. Experiences in the treatment of three cases with hyperbaric oxygen are reported. It is concluded that this treatment can be advantageously used in this disease.

[A case-control study of melanoma of the skin in the province of Torino, Italy]. / Etude cas-témoins sur le mélanome de la peau dans la province de Torino, Italie.

A population based case-control study was conducted in the province of Torino (Northern Italy) where internal migration produced a population with mixed ethnicity and lifestyles. Two hundred and eight cases of histologically confirmed cutaneous malignant melanoma (CMM) and four hundred and sixteen controls were interviewed. Our results gave evidence to the role of skin reaction to the sun (OR 5.0 in men and 2.2 in women) as an indicator of a group at risk. The increased risk of intense and occasional sun exposure as can be inferred from sun exposure during holidays and outdoor sports, has been confirmed (OR 4.1 in men and 2.7 in women). Ethnic differences did not play an important role in our population, women who used oral contraceptives also did not show an increased risk.

Combined catheter-based pulmonary valvuloplasty and atrial septal defect closure in Noonan syndrome. A case report and literature review.

The first case of combined procedure of catheter-based balloon pulmonary valvuloplasty and atrial septal defect closure using Amplatzer Septal Occluder, in a patient with Noonan syndrome, is reported. The literature regarding prevalence, genetics, pattern of involvement, symptoms, diagnosis, and treatment of this syndrome is reviewed.