Study of the general mechanism of stress corrosion of aluminum alloys and development of techniques for its detection Quarterly report, 1 Dec. 1967 - 29 Feb. 1968

Stress corrosion of aluminum alloys and techniques for its detectio

Surgical treatment of sporadic vestibular schwannoma in a series of 1006 patients. Trattamento chirurgico degli schwannomi vestibolari: risultati su una serie di 1006 pazienti

La gestione dello schwannoma vestibolare (SV) sporadico si è gradualmente evoluta negli ultimi decenni. Lo scopo di questo studio è di analizzare l’evoluzione negli esiti chirurgici dell’exeresi di queste lesioni, realizzata da un team neurotologico tra il 1990 e il 2006, attraverso differenti approcci. È stata eseguita una revisione retrospettica monocentrica dei dati clinici di 1006 pazienti. Al fine di valutare eventuali modifiche e progressi, il periodo di 17 anni è stato diviso in tre periodi, ciascuno comprendente rispettivamente 268 SV (1990- 1996), 299 SV (1997-2001), e 439 SV (2002-2006). Il follow-up medio è stato di 5,9 ± 2,4 anni. Complessivamente l’asportazione totale è stata ottenuta nel 99,4% dei casi. Il tasso di mortalità è stato dello 0,3%, la meningite e la perdita di liquido cefalo rachidiano (LCR) sono stati osservati nel 1,2% e il 9% dei casi, rispettivamente. La frequenza della perdita di LCR è diminuita dal 11,6% al 7,1% tra il primo e dell’ultimo periodo (p < 0,01) e la revisione chirurgica dal 3,4% al 0,9% (p < 0,05). Il nervo facciale è stato anatomicamente conservato nel 97,7% dei casi. Ad un anno, una buona funzione del nervo facciale è stata osservata nel 85,1% dei pazienti (I e II grado HouseBrackmann), con una variazione tra il primo e l’ultimo periodo che andava dal 78,4% al 87,6% (p < 0,05). Ad un anno post-operatorio la conservazione dell’udito è stata ottenuta nel 61,6% dei pazienti, passando dal 50,9% del primo periodo, al 69,0% del periodo piú recente (p < 0,05) (classe A + B + C dalla classificazione AAO-HNS). L’udito utile (classe A + B) è stato conservato nel 33,5% dei casi complessivamente, con percentuali comprese tra il 21,8% e 42% nel primo e nell’ultimo periodo rispettivamente (p < 0,01). Gli esiti chirurgici dell’asportazion dello schwannoma vestibolare sporadico sono migliorati negli anni per quanto riguarda i risultati funzionali del nervo facciale, la conservazione dell’udito, le perdite di liquido cefalorachidiano, principalmente grazie all’esperienza del team neurotologico. I risultati funzionali dopo la rimozione microchirurgica completa SV di grandi dimensioni dipendono dall’ esperienza maturata sulle lesioni di piccole dimensioniThe management of sporadic vestibular schwannoma (VS) has evolved in the last decades. The aim of this study was to analyse the evolution in surgical outcomes of VSs operated by a neurotological team between 1990 and 2006 by different approaches. A monocentric retrospective review of medical charts of 1006 patients was performed. In order to assess eventual changes and progress, the 17-years period was divided in three periods, each one comprehending 268 VS (1990-1996), 299 VS (1997-2001), and 439 VS (2002-2006). Mean follow-up was 5.9 ± 2.4 years. Overall, complete VS removal was achieved in 99.4% of cases. Mortality rate was 0.3%, meningitis and CSF leaks were observed in 1.2 % and 9 % of the cases, respectively. CSF leakage decreased from 11.6% to 7.1% between the first and last period (p < 0.01) as well as revision surgery from 3.4 % to 0.9 % (p < 0.05). Facial nerve was anatomically preserved in 97.7% of cases. At one year, a good facial nerve function was observed in 85.1% of patients (grade I and II of House-Brackmann grading scale), which ranged between the first and last period from 78.4% to 87.6% (p <0.05). At one year, hearing preservation was obtained in 61.6% of patients, which increased from the first period to the last one from 50.9% to 69.0% (p < 0.05) (class A+B+C from the AAO-HNS classification). Useful hearing (class A+B) was observed in 33.5% of cases overall, with 21.8% and 42% in the first and last period, respectively (p < 0.01). Surgical outcomes of sporadic vestibular schwannoma have improved concerning facial nerve function outcomes, hearing preservation and cerebrospinal fluid (CSF) leaks, mainly due to the neuro-otological team's experience. Functional results after complete microsurgical removal of large VS depend on experience gained on small VS removal

Study of the general mechanism of stress corrosion of aluminum alloys and development of techniques for its detection Annual summary report, 2 Jun. 1967 - 1 Jun. 1968

Stress corrosion cracking of high strength aluminum alloys investigated by electrochemical, mechanical, and electron microscopic technique

D-Brane Probe and Closed String Tachyons

We consider a D-brane probe in unstable string background associated with flux branes. The twist in spacetime metric reponsible for the supersymmetry breaking is shown to manifest itself in mixing of open Wilson lines with the phases of some adjoint matter fields, resulting in a nonlocal and nonsupersymmetric form of Yang-Mills theory as the probe dynamics. This provides a setup where one can study fate of a large class of unstable closed string theories that include as a limit type 0 theories and various orbifolds of type II and type 0 theories. We discuss the limit of ${\bf C}/Z_n$ orbifold in some detail and speculate on couplings with closed string tachyons.Comment: LaTeX, 17 pages, typos fixed, references update

Direct analysis of sterols from dried plasma/blood spots by an atmospheric pressure thermal desorption chemical ionization mass spectrometry (APTDCI-MS) method for a rapid screening of Smith-Lemli-Opitz syndrome.

Here is proposed a rapid and sensitive method involving atmospheric pressure thermal desorption chemical ionization mass spectrometry (APTDCI-MS) for specific laboratory screening of the Smith– Lemli–Opitz syndrome (SLOS), an inherited defect of cholesterol biosynthesis. Biochemical findings in the blood of SLOS patients are low cholesterol (Chol), high 7- and 8-dehydrocholesterol (DHCs) levels and high DHCs/Chol ratios. The APTDCI proposed method is able to ionize sterols for qualitative and quantitative analysis directly from dried plasma/blood spots. Critical APTDCI parameters – desolvation gas flow and temperature – were optimized analyzing Chol, 7-DHC and cholesteryl stearate standards spotted onto a glass slide acquiring the full scan spectra in positive ion mode. Chol levels in dried plasma spots of unaffected controls (n ¼ 23) obtained by the proposed method were compared with those of the enzymatic method (y ¼ 0.9166x + 0.3811; r ¼ 0.8831) while Chol and DHCs of SLOS patients (n ¼ 9) were compared with the gas chromatography flame ionization detection (GC-FID) method (y ¼ 0.8214x + 0.7388; r ¼ 0.8288). The APTDCI-MS method is also able to differentiate normal from SLOS samples directly analyzing whole blood and washed red cells spotted on paper. In conclusion, the intrinsic analytical high-throughput of APTDCI-MS method for sterol analysis could be useful to screen SLO syndrome

Bound States of String Networks and D-branes

We show the existence of non-threshold bound states of (p, q) string networks and D3-branes, preserving 1/4 of the full type IIB supersymmetry, interpreted as string networks dissolved in D3-branes. We also write down the expression for the mass density of the system and discuss the extension of the construction to other Dp-branes. Differences in our construction of string networks with the ones interpreted as dyons in N=4 gauge theories are also pointed out.Comment: 11 pages, latex, minor modifications (version to appear in Phys. Rev. Lett.

Fast Label Extraction in the CDAWG

The compact directed acyclic word graph (CDAWG) of a string $T$ of length $n$ takes space proportional just to the number $e$ of right extensions of the maximal repeats of $T$, and it is thus an appealing index for highly repetitive datasets, like collections of genomes from similar species, in which $e$ grows significantly more slowly than $n$. We reduce from $O(m\log{\log{n}})$ to $O(m)$ the time needed to count the number of occurrences of a pattern of length $m$, using an existing data structure that takes an amount of space proportional to the size of the CDAWG. This implies a reduction from $O(m\log{\log{n}}+\mathtt{occ})$ to $O(m+\mathtt{occ})$ in the time needed to locate all the $\mathtt{occ}$ occurrences of the pattern. We also reduce from $O(k\log{\log{n}})$ to $O(k)$ the time needed to read the $k$ characters of the label of an edge of the suffix tree of $T$, and we reduce from $O(m\log{\log{n}})$ to $O(m)$ the time needed to compute the matching statistics between a query of length $m$ and $T$, using an existing representation of the suffix tree based on the CDAWG. All such improvements derive from extracting the label of a vertex or of an arc of the CDAWG using a straight-line program induced by the reversed CDAWG.Comment: 16 pages, 1 figure. In proceedings of the 24th International Symposium on String Processing and Information Retrieval (SPIRE 2017). arXiv admin note: text overlap with arXiv:1705.0864

Measurement of the absolute gas gain and gain variations study in straw-tube detectors

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Near-extremal and extremal quantum-corrected two-dimensional charged black holes

We consider charged black holes within dilaton gravity with exponential-linear dependence of action coefficients on dilaton and minimal coupling to quantum scalar fields. This includes, in particular, CGHS and RST black holes in the uncharged limit. For non-extremal configuration quantum correction to the total mass, Hawking temperature, electric potential and metric are found explicitly and shown to obey the first generalized law. We also demonstrate that quantum-corrected extremal black holes in these theories do exist and correspond to the classically forbidden region of parameters in the sense that the total mass $M_{tot}<Q$ ($Q$ is a charge). We show that in the limit $T_{H}\to 0$ (where $T_{H}$ is the Hawking temperature) the mass and geometry of non-extremal configuration go smoothly to those of the extremal one, except from the narrow near-horizon region. In the vicinity of the horizon the quantum-corrected geometry (however small quantum the coupling parameter $\kappa$ would be) of a non-extremal configuration tends to not the quantum-corrected extremal one but to the special branch of solutions with the constant dilaton (2D analog of the Bertotti-Robinson metric) instead. Meanwhile, if $\kappa =0$ exactly, the near-extremal configuration tends to the extremal one. We also consider the dilaton theory which corresponds classically to the spherically-symmetrical reduction from 4D case and show that for the quantum-corrected extremal black hole $M_{tot}>Q$.Comment: 25 pages. Typos corrected. To appear in Class. Quant. Gra