Formation, characterization, and stability of methaneselenolate monolayers on Au(111): an electrochemical high-resolution photoemission spectroscopy and DFT study.

We investigated the mechanism of formation and stability of self-assembled monolayers (SAMs) of methaneselenolate on Au(111) prepared by the immersion method in ethanolic solutions of dimethyl diselenide (DMDSe). The adsorbed species were characterized by electrochemical measurements and high-resolution photoelectron spectroscopy (HR-XPS). The importance of the headgroup on formation mechanism and the stability of the SAMs was addressed by comparatively studying methaneselenolate (MSe) and methanethiolate (MT) monolayers. Density Functional Theory (DFT) calculations were performed to identify the elementary reaction steps in the mechanisms of formation and decomposition of the monolayers. Reductive desorption and HR-XPS measurements indicated that a MSe monolayer is formed at short immersion times by the cleavage of the Se-Se bond of DMDSe. However, the monolayer decomposes at long immersion times at room temperature, as evidenced by the appearance of atomic Se on the surface. The decomposition is more pronounced for MSe than for MT monolayers. The MSe monolayer stability can be greatly improved by two modifications in the preparation method: immersion at low temperatures (-20 °C) and the addition of a reducing agent to the forming solution.

Adlayers of alkanedithiols on Au(111): effect of disulfide reducing agent.

High-resolution photoemission spectroscopy is used to characterize adlayers of ethane-, hexane-, and nonanedithiol molecules grown on Au(111) surfaces by the immersion method. The effect of using a reducing agent during and after the immersion to inhibit or eliminate S-S bonds is investigated. Our results demonstrate that immersion 24 h in millimolar dithiol ethanolic solutions gives rise to the formation of multilayers; this effect is more pronounced in the case of ethanedithiol, the shortest molecule. A post-treatment with a disulfide reducing agent is effective to produce monolayers of standing-up molecules; this effect is again more pronounced in the case of ethanedithiol. Finally, the immersion 24 h in a solution containing dithiol and the reducing agent gives an unexpected result: most molecules remain adsorbed in the lying-down configuration; in this case, the almost complete suppression of the standing-up phase occurs equally with the three types of molecules, which suggests that the formation of S-S bonds must be important for the lifting of the molecules.

Electrochemical, high-resolution photoemission spectroscopy and vdW-DFT study of the thermal stability of benzenethiol and benzeneselenol monolayers on Au(111).

The preparation and thermal stability of benzenethiol and benzeneselenol self-assembled monolayers (SAMs) grown on Au(111) have been investigated by electrochemical experiments and high-resolution photoemission spectroscopy. Both techniques confirm the formation of monolayers with high packing densities (θ = 0.27-0.29 ML) and good degrees of order in both cases. Despite many similarities between the two SAMs, the thermal desorption is distinctly different: whereas the benzenethiol SAM desorbs in a single steplike process, the desorption of the benzeneselenol SAM occurs with a much lower activation energy and involves the cleavage of some Se-C bonds and a change in molecular configuration from standing up to lying down. This behavior is explained by considering the different nature of the bonding of the headgroup with the metal surface and with the phenyl ring. Density functional theory calculations show that the breakage of the Se-C bond has a lower activation energy barrier than the breakage of the S-C bond.

[Adrenalectomy and radical nephrectomy due to renal carcinoma]. / Surrenalectomia e nefrectomia radicale per carcinoma renale. Considerazioni.

BACKGROUND: Surgery remains the only effective treatment for renal carcinoma. According the current surgical procedure, both the neoplastic kidney with its perirenal tissue and the Gerota fascia with adrenal gland must be removed. In the last years, the utility of routine adrenalectomy for kidney cancer surgery has been questioned and some authors now recommend this procedure just in selected cases. METHODS: In order to provide a contribution to this debate, 350 cases of nephrectomy after renal carcinoma have been reviewed. In all, 185 adrenalectomy have been performed and neoplastic involvement of adrenal gland has been identified just in 9 cases (4.9%), suggesting a rarity of tumor progression to adrenal gland at the time of surgery. RESULTS: Moreover, neoplastic involvement of adrenal gland has been shown in just 3 cases at preoperatively CT scan. CONCLUSIONS: The conclusion is drawn that adrenal gland may be retained in surgery for radical nephrectomy after renal carcinoma. Adrenalectomy may be recommended in doubtful cases, especially in upper pole localization and in large tumours.

[Spontaneous perirenal extravasation of urine]. / Lo stravaso perirenale spontaneo d'urina.

Perirenal urinary extravasation in the course of violent renal colic appears to occur much more frequently than is reported in the literature. In this study, the authors report on three such cases observed personally in the space of one year and discuss the pathophysiological factors which may give rise to this phenomenon.

[Desmoid tumors (apropos of a clinical case)]. / I tumori desmoidi (a proposito di un caso clinico).

The authors, starting from a case of desmoid tumour of abdominal wall, they had the opportunity to observe, discuss its possible etiopathogenetic factors, and confirm the validity of operation as the only therapy.

[Gastric leiomyoma (presentation of 3 clinical cases)]. / Il leiomioma gastrico (presentazione di tre casi clinici).

Gastric leiomyoma represents a rather rare report in abdominal surgery, above all because it very often shows no symptoms. Among the non-epithelial gastric neoplasms, it occupies the second place after lymphoma. After describing its anatomo-pathological aspects and clinical features, the authors report their casuistry, including three observations of such neoplasm, and point out that both the endoscopic inspection and the bioptic abstraction, contextually performed, were not so useful in formulating a sure preoperative diagnosis.

[Urologic complications in kidney transplants: experience in 274 transplants]. / Le complicanze urologiche nel trapianto renale: esperienza su 274 trapianti.

The urological complications after a renal transplantation still represent an event anything but rare, ranging, according to the different statistics, from 0.9% up to 23%, with a mortality between 0 and 25%. In this work done by the Verona Centre the experience on 274 transplantations is reported. The urological complications weighed with 6.2% and absence of mortality among the patients. The importance of the prevention and precocious diagnosis is confirmed.