2,994 research outputs found
Benefici e svantaggi delle eparine a basso peso molecolare
Premesse e Scopo dello studio: Le eparine a basso peso molecolare vengono utilizzate per la prevenzione e il trattamento della coagula- zione del sangue, l’obiettivo è quello di ridurre al minimo gli effetti collaterali in seguito alla somministrazione delle varie molecole. Metodi e Risultati: L’analisi stata effettuata presso il Dipartimento di Chirurgia Generale e di Urgenza dell’A.O. Ospedali riuniti Villa Sofia - Cervello, su un campione di circa 80 pazienti con età compresa tra i 35-80 anni, 50 sono di sesso femminile e 30 sono di sesso maschile, sono stati riscontrati dall'osservazione effettuata i seguenti effetti collaterali: per quanto riguarda la Parnaparina e la Bemiparina sanguinamento delle gengive durante il lavaggio dei denti maggiormente in soggetti anziani (3 donne); mestruazioni particolarmente abbondanti (7 donne); eccessiva perdita di sangue per tagli o piccole ferite (5 donne e 5 uomini); ematomi in sede d'inezione (in tutti i pazienti osservati). Conclusioni: Dalle analisi finali possiamo dedurre che la Parnaparina e la Bemiparina svolgono un’intensa e rapida dissoluzione di trombi che possono essersi formati nelle arterie o nelle vene mentre con la Nadroparina e con l’Enoxaparina non abbiamo mai osservato variazioni dell'A.P. E della P.T.T
Low pH immobilizes and kills human leukocytes and prevents transmission of cell-associated HIV in a mouse model
BACKGROUND: Both cell-associated and cell-free HIV virions are present in semen and cervical secretions of HIV-infected individuals. Thus, topical microbicides may need to inactivate both cell-associated and cell-free HIV to prevent sexual transmission of HIV/AIDS. To determine if the mild acidity of the healthy vagina and acid buffering microbicides would prevent transmission by HIV-infected leukocytes, we measured the effect of pH on leukocyte motility, viability and intracellular pH and tested the ability of an acidic buffering microbicide (BufferGel(®)) to prevent the transmission of cell-associated HIV in a HuPBL-SCID mouse model. METHODS: Human lymphocyte, monocyte, and macrophage motilities were measured as a function of time and pH using various acidifying agents. Lymphocyte and macrophage motilities were measured using video microscopy. Monocyte motility was measured using video microscopy and chemotactic chambers. Peripheral blood mononuclear cell (PBMC) viability and intracellular pH were determined as a function of time and pH using fluorescent dyes. HuPBL-SCID mice were pretreated with BufferGel, saline, or a control gel and challenged with HIV-1-infected human PBMCs. RESULTS: Progressive motility was completely abolished in all cell types between pH 5.5 and 6.0. Concomitantly, at and below pH 5.5, the intracellular pH of PBMCs dropped precipitously to match the extracellular medium and did not recover. After acidification with hydrochloric acid to pH 4.5 for 60 min, although completely immotile, 58% of PBMCs excluded ethidium homodimer-1 (dead-cell dye). In contrast, when acidified to this pH with BufferGel, a microbicide designed to maintain vaginal acidity in the presence of semen, only 4% excluded dye at 10 min and none excluded dye after 30 min. BufferGel significantly reduced transmission of HIV-1 in HuPBL-SCID mice (1 of 12 infected) compared to saline (12 of 12 infected) and a control gel (5 of 7 infected). CONCLUSION: These results suggest that physiologic or microbicide-induced acid immobilization and killing of infected white blood cells may be effective in preventing sexual transmission of cell-associated HIV
Beam manipulation for resonant plasma wakefield acceleration
Plasma-based acceleration has already proved the ability to reach ultra-high accelerating gradients. However
the step towards the realization of a plasma-based accelerator still requires some e
ff ort to guarantee high brightness beams, stability and reliability. A significant improvement in the efficiency of PWFA has been
demonstrated so far accelerating a witness bunch in the wake of a higher charge driver bunch. The transformer
ratio, therefore the energy transfer from the driver to the witness beam, can be increased by resonantly exciting
the plasma with a properly pre-shaped drive electron beam. Theoretical and experimental studies of beam
manipulation for resonant PWFA will be presented her
Discovery of the Eu decay
We report on the first compelling observation of decay of Eu
to the ground state of Pm. The measurement was performed using a 6.15 g
LiEu(BO) crystal operated as a scintillating bolometer. The Q-value
and half-life measured are: Q = 1948.9 keV, and
T y . The
half-life prediction of nuclear theory using the Coulomb and proximity
potential model are in good agreement with this experimental result
Non-linear macroscopic polarization in III-V nitride alloys
We study the dependence of macroscopic polarization on composition and strain
in wurtzite III-V nitride ternary alloys using ab initio density-functional
techniques. The spontaneous polarization is characterized by a large bowing,
strongly dependent on the alloy microscopic structure. The bowing is due to the
different response of the bulk binaries to hydrostatic pressure, and to
internal strain effects (bond alternation). Disorder effects are instead minor.
Deviations from parabolicity (simple bowing) are of order 10 % in the most
extreme case of AlInN alloy, much less at all other compositions. Piezoelectric
polarization is also strongly non-linear. At variance with the spontaneous
component, this behavior is independent of microscopic alloy structure or
disorder effects, and due entirely to the non-linear strain dependence of the
bulk piezoelectric response. It is thus possible to predict the piezoelectric
polarization for any alloy composition using the piezoelectricity of the parent
binaries.Comment: RevTex 7 pages, 7 postscript figures embedde
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