707 research outputs found
Multigap RPC time resolution to 511 keV annihilation photons
The time resolution of Multigap Resistive Plate Counters (MRPCs) to keV
gamma rays has been investigated using a Na source and four detectors.
The MRPCs time resolution has been derived from the Time-of-Flight information,
measured from pairs of space correlated triggered events. A GEANT4 simulation
has been performed to analyze possible setup contributions and to support
experimental results. A time resolution (FWHM) of ps and ps has
been measured for a single MRPC with four m gas gaps by considering
respectively one and two independent pairs of detectors.Comment: 25 pages, 14 figure
Multiangle static and dynamic light scattering in the intermediate scattering angle range
We describe a light scattering apparatus based on a novel optical scheme
covering the scattering angle range 0.5\dg \le \theta \le 25\dg, an
intermediate regime at the frontier between wide angle and small angle setups
that is difficult to access by existing instruments. Our apparatus uses
standard, readily available optomechanical components. Thanks to the use of a
charge-coupled device detector, both static and dynamic light scattering can be
performed simultaneously at several scattering angles. We demonstrate the
capabilities of our apparatus by measuring the scattering profile of a variety
of samples and the Brownian dynamics of a dilute colloidal suspension
An overview of coumarin as a versatile and readily accessible scaffold with broad-ranging biological activities
Privileged structures have been widely used as an effective template for the research and discovery of high value chemicals. Coumarin is a simple scaffold widespread in Nature and it can be found in a considerable number of plants as well as in some fungi and bacteria. In the last years, these natural compounds have been gaining an increasing attention from the scientific community for their wide range of biological activities, mainly due to their ability to interact with diverse enzymes and receptors in living organisms. In addition, coumarin nucleus has proved to be easily synthetized and decorated, giving the possibility of designing new coumarin-based compounds and investigating their potential in the treatment of various diseases. The versatility of coumarin scaffold finds applications not only in medicinal chemistry but also in the agrochemical field as well as in the cosmetic and fragrances industry. This review is intended to be a critical overview on coumarins, comprehensive of natural sources, metabolites, biological evaluations and synthetic approaches
Sono Francesco
E se Francesco d'Assisi fosse vissuto ai giorni nostri? Francesco ha diciotto anni e un grande fuoco che gli arde dentro. Non \ue8 capace di stare fermo un attimo e conduce una vita a cento all'ora, tra discoteche e ristoranti di lusso insieme agli amici. Grazie alla sua famiglia, non ha problemi di soldi e pu\uf2 avere tutto ci\uf2 che desidera. Francesco per\uf2 non sa che cosa desidera. Forse sono le ragazze. Forse sono le corse in moto. Forse \ue8 semplicemente il divertimento puro. Ma se fosse qualcosa di pi\uf9? Qualcosa che non riesce a vedere, mentre sfreccia per le strade della citt\ue0, in sella al suo bolide? Sar\ue0 l'incredibile incontro con don G. a cambiare tutto e a spingere il ragazzo a rallentare, fino a fermarsi, per osservare ci\uf2 che gli sta attorno. Un mondo fatto di piccole e grandi sofferenze, di ingiustizie, solitudine, ma anche pieno di persone dal cuore grande, pronte a rimboccarsi le maniche per aiutare gli altri. Grazie al confronto con gli amici, Chiara e Ruf, Francesco decider\ue0 cos\uec di mettersi in viaggio, percorrendo a piedi mezza Italia, per scoprire che cosa vuole e chi \ue8 per davvero. Dopo "Ammare", i Pellai orchestrano un racconto senza tempo, dimostrando che la storia di Francesco d'Assisi \ue8 pi\uf9 moderna che mai. I Pellai ci regalano un romanzo in cui Francesco \ue8 un adolescente del nostro millennio. Pieno di dubbi, desideri, passioni. Pronto a sbagliare, ma anche a cambiare il mondo. Et\ue0 di lettura: da 12 anni
Bacterial Cholangitis, Cholecystitis, or both in Dogs
BACKGROUND: Bacterial cholangitis and cholecystitis are rarely reported, poorly characterized diseases in the dog. OBJECTIVES: To characterize the clinical features of these conditions. ANIMALS: Twentyâseven clientâowned dogs with bacterial cholangitis, cholecystitis, or both. METHODS: Multicenter, retrospective cases series of dogs with bacterial cholangitis, cholecystitis, or both, presenting January 2000 to June 2011 to 4 Veterinary Schools in Ireland/United Kingdom. Interrogation of hospital databases identified all cases with the inclusion criteria; histopathologically confirmed cholangitis or cholecystitis and bile culture/cytology results supporting a bacterial etiology. RESULTS: Twentyâseven dogs met the inclusion criteria with approximately 460 hepatitis cases documented over the same study period. Typical clinical pathology findings were increases in liver enzyme activities (25/26), hyperbilirubinemia (20/26), and an inflammatory leukogram (21/24). Ultrasound findings, although nonspecific, aided decisionâmaking in 25/26 cases. The most frequent hepatobiliary bacterial isolates were Escherichia coli (n = 17; 16 cases), Enterococcus spp. (n = 8; 6 cases), and Clostridium spp. (n = 5; 5 cases). Antimicrobial resistance was an important feature of aerobic isolates; 10/16 E. coli isolates resistant to 3 or more antimicrobial classes. Biliary tract rupture complicated nearly one third of cases, associated with significant mortality (4/8). Discharged dogs had a guarded to fair prognosis; 17/18 alive at 2 months, although 5/10 reâevaluated had persistent liver enzyme elevation 2â12 months later. CONCLUSION AND CLINICAL SIGNIFICANCE: Bacterial cholangitis and cholecystitis occur more frequently than suggested by current literature and should be considered in dogs presenting with jaundice and fever, abdominal pain, or an inflammatory leukogram or with ultrasonographic evidence of gallbladder abnormalities
Chronic exertional compartment syndrome of the forearm: a systematic review
The aim of this systematic review is to understand which surgical procedure provides better results in terms of pain relief and function in the treatment of chronic exertional compartment syndrome (CECS) of the forearm. We searched Medline (PubMed), Web of Science, Embase and Scopus databases on 8 July 2020. Twelve studies were included in this review. We assessed the quality of the studies using the Coleman Methodological Score. Data on demographic features, operative readings, diagnostic methods, follow-up periods, type and rates of complications, survivorship of the procedure, return to sport activity, and outcome measures were recorded. In conclusion, compared to the other techniques, endoscopic fasciotomy delivers similar success rates and lower incidence of complications
Folates in Trypanosoma brucei: achievements and opportunities
Trypanosoma brucei is the agent of human African trypanosomiasis (HAT), a neglected disease that threatens the lives of 65 million people in sub-Saharan Africa every year. Unfortunately, available therapies are unsatisfactory, due primarily to safety issues and development of drug resistance. Over the last decades significant effort has been made in the discovery of new potential anti-HAT agents, with help from the World Health Organization (WHO) and private\u2013public partnerships such as the Drugs for Neglected Diseases Initiative (DNDi). Whereas antifolates have been a valuable source of drugs against bacterial infections and malaria, compounds effective against T. brucei have not yet been identified. Considering the relatively simple folate metabolic pathway in T. brucei, along with results obtained in this research field so far, we believe that further investigations might lead to effective chemotherapeutic agents. Herein we present a selection of the more promising results obtained so far in this field, underlining the opportunities that could lead to successful therapeutic approaches in the future
Rationalizing the Lacking of Inversion Symmetry in a Noncentrosymmetric Polar Racemate : an Experimental and Theoretical Study
The total charge density of PYRAC, a polar (Pca21) organic racemate with Z\u2032 = 2, was derived from high-resolution single-crystal X-ray diffraction data at T = 100(2) K and periodic DFT calculations. The PYRAC asymmetric unit consists of a hydrogen-bonded pair of conformationally different enantiomers, A and Bi, where the subscript \u201ci\u201d indicates a reversed absolute configuration. The lattice stability was compared with that of centrosymmetric possibly competing structures, with the aim of understanding why a noncentrosymmetric lattice framework is obtained from a racemic mixture. The likelihood of specific intermolecular recognition processes among different conformers of PYRAC in the very first stages of nucleation was investigated by DFT simulations in vacuo. Two competing, equivalent interconversion pseudorotatory paths between the most stable A and the least stable B conformers were found. It results that molecules spend most of their time ( 4853%) in the A conformation, whereas the B one is far less populated ( 487%). Therefore, centrosymmetric AAi adducts are formed very frequently in the reaction liquor, whereas the BBi ones are rare. Nevertheless, AAi pairs produce crystal forms with cohesive energies and densities significantly less favorable than those estimated for the noncentrosymmetric heterochiral ABi ones. Therefore, preference for Z\u2032 = 2 in conjunction with noncentrosymmetric point and space groups results from the thermodynamic control of the crystallization process. The capability of forming extended hydrogen bond chains throughout the lattice appears to be a prerequisite to bind together the fundamental ABi repeating units
Identification of a novel spliced variant of the SYT gene expressed in normal tissues and in synovial sarcoma
Synovial sarcoma (SS) is cytogenetically characterized by the translocation t(X;18)(p11.2-q11.2) generating a fusion between the SYT gene on chromosome 18 and one member of the SSX family gene (SSX1; SSX2; SSX4) on chromosome X. Here, we report for the first time that 2 forms of SYT mRNA are present in both normal tissues and SSs. By amplifying the full-length SYT cDNA of two SSs, we detected 2 bands, here designated N-SYT and I-SYT. The latter, previously undescribed, contains an in-frame insertion of 93âbp. Its sequencing revealed a 100% homology with the mouse SYT gene. These two SYT forms were present, although in different amounts, in all human normal tissues examined, including kidney, stomach, lung, colon, liver and synovia. Coexistence of N-SYT and I-SYT (both fused with SSX) was detected in a series of 59 SSs (35 monophasic and 24 biphasic) and in a SS cell line. A preliminary analysis of the differential expression levels of N-SYT and I-SYT in SSs revealed that the latter was consistently overexpressed, suggesting a role in SS pathogenesis. Š 2001 Cancer Research Campaign http://www.bjcancer.co
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