Metal work-function changes induced by organic adsorbates: a combined experimental and theoretical study

The role of molecular dipole moment, charge transfer, and Pauli repulsion in determining the work-function change (Deltaphi) at organic-metal interfaces has been elucidated by a combined experimental and theoretical study of (CH(3)S)(2)/Au(111) and CH(3)S/Au(111). Comparison between experiment and theory allows us to determine the origin of the interface dipole layer for both phases. For CH(3)S/Au(111), Deltaphi can be ascribed almost entirely to the dipole moment of the CH(3)S layer. For (CH(3)S)(2)/Au(111), a Pauli repulsion mechanism occurs. The implications of these results on the interpretation of Deltaphi in the presence of strongly and weakly adsorbed molecules is discussed.     

Some possible precursors of the main earthquakes of the Tornimparte (Central Italy) seismic sequence occurred in 1985

Summary Two tiltmeters installed at Peschiera site (Central Italy) generally showed trends that differ from the ones obtained at the network located in the Apennine region of Central Italy. Detrended tilt recordings reveal the presence of an anomalous variation during the first months of 1985. We propose to interpret this anomaly as a precursor of the main earthquakes of the seismic sequence occurred at Tornimparte area (Central Italy). The results of the deep-resistivity measurements obtained from June 1983 to December 1985 at Pizzoli area (Central Italy) reveal anomalous resistivity changes occurred at the end of May 1985. We propose that also this anomalous variation is connected with the Tornimparte seismic sequence.

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Riassunto Due inclinometri installati in località Sorgenti del Peschiera (Italia Centrale) hanno evidenziato andamenti in generale diversi rispetto a quelli ottenuti dalla rete inclinometrica situata nella regione appenninica dell'Italia Centrale. Le tracce filtrate hanno messo in risalto la presenza di una variazione anomala verificatasi nei primi mesi del 1985. Si propone d'interpretare questa anomalia come precursore dei terremoti principali della sequenza sismica avvenuta nella zona di Tornimparte (Italia Centrale). I risultati delle misure di resistività profonda ottenuti da giugno 1983 a dicembre 1985 nell'area di Pizzoli (Italia Centrale) hanno evidenziato una variazione anomala di resistività alla fine di maggio 1985. Si propone che anche questa anomalia sia connessa alla sequenza sismica di Tornimparte.

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Резюме Показания двух инклинометров, установленных в Пескиере (Центральная Италия) обычно отличаются от данных, полученных на станциях в Апеннинах Центральной Италии. Анализ данных обнаруживает аномальное отклонение в первые месяцы 1985 года. Мы предлагаем интерпретировать эту аномалию как предвестник главных змелятрясений сейсмической последовательности, наблюдавшейся в области Торнимпарте (Центральная Пталия). Результаты измерений глубинного сопротивления, полученные с июня 1983 г. по декабря 1985 г. в области Пиццоли (Центральная Италия), обнаруживают аномальные изменения сопротивления в конце мая 1985 г. Мы предполагаем, что это аномальное изменение также связано с сейсмической последовательностью в области Торнимпарте.

     

Lipophilic character of cardiac glycosides: correlation between RM values and acute toxicity data in different animal species

The RM for a new series of cardiac glycosides were calculated by means of some of the delta RM values previously derived from another series of compounds. The experimental or calculated RM values of both series of derivatives were correlated with the acute toxicity data (log 1/C). The slopes of the linear equations for cats, dogs, guinea-pigs and frogs are very close, showing that the dependence of toxicity on the lipophilic character is the same in these animal species.     

Underground monitoring system of electromagnetic emissions.

Summary In the last few years systematic investigations concerning electromagnetic precursors of earthquakes have been carried out by many authors. The studies regarding the electric component of electromagnetic emissions are made with surface or underground equipments. An electromagnetic-emission monitoring system suitable for underground deployment has been made at the Physics Department of the ?La Sapienza? University of Rome. The system is able to detect electric signals with an amplitude up to about 100 mV and a freqeency band that lies between 0.3 and 300 kHz. This equipment has been installed in a deep cave in the Central Apennines. In order to carry out correlations with the local seismicity, also a seismic detector has been placed in the same cave. All output data are recorded by a tape recorder; the entire system has a fortnightly self-sufficiency.

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Riassunto In questi ultimi anni sono state condotte da diversi autori ricerche sistematiche riguardanti i precursori elettromagnetici di terremoti. Gli studi sulla componente elettrica delle emissioni elettromagnetiche si effettuano con strumentazioni, di superficie o sotterranee. Presso il Dipartimento di Fisica dell'Università di Roma ?La Sapienza? è stato realizzato un sistema di monitoraggio delle emissioni elettromagnetiche adatto all'installazione sotterranea. Il sistema può rilevare segnali elettrici di ampiezza fino a circa 100 m V e con una banda di frequenza di (0.3÷300) kHz. Tale strumentazione è stata installata in una profonda grotta dell'Appennino Centrale. Nella stessa grotta è stato posto anche un sismografo allo scopo di evidenziare correlazioni con la sismicità locale. I dati si registrano su un registratore a nastro; l'autonomia dell'intero apparato è quindicinale.

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Резюме В последние несколько лет проводятся систематические исследования, касающиеся электромагнитных предвестников эемлетрясений. Изучение электрической компоненты электромагнитного излучения проводится с помощью наземного и подземного оборудования. Система мониторирования электромгнитных нзлучений была разработана в денартаменте физики Римского универстета. Разработанная система способна детектировать электрические сигналы с амплитудой вплоть до 100 мВ и в частотном диапазоне (0.03÷300) кГц. Это оборудование установлено в глубокой полости в центральных Апеннинах. В той же полости расположен сейсмический детектор, чтобы определить корреляции с локальной сейсмичностью. Все выходные данные записываются на магнитофон; система обладает двухнедельной автономией.

     

Variations in the relationship of seismic velocities before two earthquakes in Imbria (Italy)

Summary The variation of thev _P /v _S relationship between the velocities of longitudinal and transverse seismic waves in an area of Central Italy has been examined between January 1979 and March 1980. SP seimograms, recorded by a three-station network, have been used duringM≤4.2 earthquakes. Such events took place along an active zone which included the epicentre areas of the two strong shallow earthquakes which occurred in Umbria on 19-9-1979 (M=5.4) and on 28-2-1980 (M=4.8), respectively. This study has allowed us to mark clear anomalies before such events took place. It has been possible also to mark certain differences in the anomalous variation of thev _P /v _S relationship for different values of the focal depth with respect to the events which have been studied.

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Riassunto è stata studiata la variazione del rapportov _P /v _S fra le velocità delle onde sismiche longitudinali e trasversali in un'area del centro Italia, nel periodo Gennaio 1979-Marzo 1980. Sono stati utilizzati i sismogrammi SP, registrati da una rete di tre stazioni, in occasione di terremoti conM≤4.2. Tali eventi si sono manifestati in una fascia attiva comprendente le aree epicentrali dei due forti terremoti superficiali che hanno interessato l'Umbria, rispettivamente il 19-9-1979 (M=5.4) e il 28-2-1980 (M=4.8). Lo studio effettuato ha permesso di rilevare l'esistenza di nette anomalie prima del verificarsi di questi due eventi. è stato inoltre possibile evidenziare differenze nella variazione anomala del rapportov _P /v _S per valori diversi della profondità ipocentrale degli eventi studiati.

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Резюме Исследуется изменение отношенияv _P /v _S между скоростями продольной и поперечной сейсмических волн в центре Италии в период с января 1979 г. по март 1980 г. Используются SP сейсмограммы, зарегистрированные с помощью трех станций в случае землетрясений сM≤4.2. Такие события имели место в активной зоне, включающей области эпицентров двух сильных неглубоких землетрясений, которые произошли в Умбрии 19/09/1979 (M=5.4) и 28/02/1980 (M=4.8). Такое исследование позволяет выделить явные аномалии, предшествующие таким событиям. Можно отметить определенные различия в аномальном изменении отношенияv _P /v _S для различных значений глубины эпицентров исследуемых событий.

     

Discovery of Monoacylglycerol Lipase (MAGL) Inhibitors Based on a Pharmacophore-Guided Virtual Screening Study

Monoacylglycerol lipase (MAGL) is an important enzyme of the endocannabinoid system that catalyzes the degradation of the major endocannabinoid 2-arachidonoylglycerol (2-AG). MAGL is associated with pathological conditions such as pain, inflammation and neurodegenerative diseases like Parkinson’s and Alzheimer’s disease. Furthermore, elevated levels of MAGL have been found in aggressive breast, ovarian and melanoma cancer cells. Due to its different potential therapeutic implications, MAGL is considered as a promising target for drug design and the discovery of novel small-molecule MAGL inhibitors is of great interest in the medicinal chemistry field. In this context, we developed a pharmacophore-based virtual screening protocol combined with molecular docking and molecular dynamics simulations, which showed a final hit rate of 50% validating the reliability of the in silico workflow and led to the identification of two promising and structurally different reversible MAGL inhibitors, VS1 and VS2. These ligands represent a valuable starting point for structure-based hit-optimization studies aimed at identifying new potent MAGL inhibitors.     

Complexity and robustness of frame structures

In structural engineering, the word “complex” is often employed to define something that is difficult to understand or to solve. Anyhow, even if the concept is extensively employed in the practice, any proper definition has not been formulated yet. Taking one’s cue from other scientific disciplines, a metric for complexity based on the performance of the load paths through the structural scheme is proposed. Referring to frames, characterized by large interaction between the beams, an analysis based on graph theory is proposed. A beam importance factor is then deduced and preliminary robustness properties are discussed. Three examples are proposed in order to examine the capabilities of the complexity indices and the beam importance factor. The structural robustness is then worked-out. Load redistribution, which represents an important aspect in structural behavior, should act in the structure in such a way that a damage would not cause collapse. The effects of a prescribed damage on a frame are analyzed and commented.