107 research outputs found

    Potential for building Façade-integrated solar thermal collectors in a highly urbanized context

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    Development of technologies, materials, support systems, and coatings has made the integration of solar thermal systems into the building envelope increasingly possible. Solar thermal collectors can either be directly integrated, substituting conventional roof or façade covering materials, or constitute independent devices added to a roof or façade structure. Aimed at estimating the real effectiveness of building-integrated solar systems for domestic heat water (DHW) production or for heating integration, when horizontal or inclined pitches on buildings are not applicable, the authors analyze a case study with different scenarios, taking into account the issues connected to a highly urbanized context in the Mediterranean climate. A GIS model was used for estimating the energy balance, while the real producibility of the simulated systems was calculated by a dynamic hourly simulation model, realized according to ISO 52016. The savings in terms of primary energy needs obtained by installing solar thermal systems on the facade are presented, and the differences between the cases in which the system is used for DHW production only and for space heating too are distinguished and discussed. The evaluated potential is quantified in the absence of roof collectors, despite their high potential in the Mediterranean region, in order to better appreciate the effects induced by integrated facade systems

    Synthesis and biological evaluation of phosphonated dihydroisoxazole nucleosides

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    Phosphonated isoxazolinyl nucleosides have been prepared via 1,3-dipolar cycloaddition reaction of nitrile oxides with corresponding vinyl or allyl nucleobases for antiviral studies. The cytotoxicity, the anti-HSV activity and the RT-inhibitory activity of the obtained compounds were evaluated and compared with those of AZT and diethyl{(10SR,40RS)-10-[[(5-methyl-2,4-dioxo-3,4- dihydropyrimidin-1(2H)-yl)]-30-methyl-20-oxa-30-azacyclopent-40-yl]}methylphosphonate, a saturated phosphonated dihydroisoxazole nucleoside analogue

    Phosphonated Carbocyclic 2'-Oxa-3'-azanucleosides as New Antiretroviral Agents

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    Phosphonated carbocyclic 2¢-oxa-3¢-azanucleosides have been synthesized and tested for their antiretroviral activity. The obtained results have shown that some of the compounds were as powerful as azydothymidine in inhibiting the reverse transcriptase activity of the human retrovirus T-cell leukemia/lymphotropic virus type 1 and in protecting human peripheral blood mononuclear cells against human retrovirus T-cell leukemia/ lymphotropic virus type 1 transmission in vitro. These data indicate that phosphonated carbocyclic 2¢-oxa- 3¢-azanucleosides possess the necessary requirements to efficiently counteract infections caused by human retroviruses

    Synthesis of phosphonated carbocyclic 2 '-oxa-3 '-aza-nucleosides: Novel inhibitors of reverse transcriptase

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    Phosphonated carbocyclic 2'-oxa-3'-aza-nucleosides have been synthesized in good yields by 1,3-dipolar cycloaddition methodology. The cytotoxicity and the reverse transcriptase inhibitory activity of the obtained compounds have been investigated. Phosphonated carbocyclic 2'-oxa-3'-aza-nucleosides, while showing low levels of cytotoxicity, exert a specific inhibitor activity on two different reverse transcriptases, which is comparable with that of AZT, opening new perspectives on their possible use as therapeutic agents, in anti-retroviral and anti-HBV chemotherapy

    Monsignor Luigi Biraghi e i falsi di Cernusco

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    We present here some reflections on an inscription from Cernusco sul Naviglio (Milan) discovered by Monsignor Luigi Biraghi in 1849 and published by Mommsen among the falsae in CIL V 664*. This paper stems from the discovery of some private and unpublished letters by Biraghi that we consulted at the Archive of the Quadronno Institute of the Sisters of St. Marcellina in Milan. This correspondence informs us of Biraghi\u2019s personal and professional relationships with other mid-19th century classical scholars. The analysis of these documents will shed some light on the harsh judgment that Mommsen (along with others) expressed on Biraghi regarding some inscriptions that he had discovered in the Ager Mediolanensis

    Tumor-Shed PGE2 Impairs IL2Rγc-Signaling to Inhibit CD4+ T Cell Survival: Regulation by Theaflavins

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    BACKGROUND:Many tumors are associated with decreased cellular immunity and elevated levels of prostaglandin E2 (PGE2), a known inhibitor of CD4+ T cell activation and inducer of type-2 cytokine bias. However, the role of this immunomodulator in the survival of T helper cells remained unclear. Since CD4+ T cells play critical roles in cell-mediated immunity, detail knowledge of the effect tumor-derived PGE2 might have on CD4+ T cell survival and the underlying mechanism may, therefore, help to overcome the overall immune deviation in cancer. METHODOLOGY/PRINCIPAL FINDINGS:By culturing purified human peripheral CD4+ T cells or Jurkat cells with spent media of theaflavin- or celecoxib-pre-treated MCF-7 cells, we show that tumor-shed PGE2 severely impairs interleukin 2 receptor gammac (IL2Rgammac)-mediated survival signaling in CD4+ T cells. Indeed, tumor-shed PGE2 down-regulates IL2Rgammac expression, reduces phosphorylation as well as activation of Janus kinase 3 (Jak-3)/signal transducer and activator of transcription 5 (Stat-5) and decreases Bcl-2/Bax ratio thereby leading to activation of intrinsic apoptotic pathway. Constitutively active Stat-5A (Stat-5A1 6) over-expression efficiently elevates Bcl-2 levels in CD4+ T cells and protects them from tumor-induced death while dominant-negative Stat-5A over-expression fails to do so, indicating the importance of Stat-5A-signaling in CD4+ T cell survival. Further support towards the involvement of PGE2 comes from the results that (a) purified synthetic PGE2 induces CD4+ T cell apoptosis, and (b) when knocked out by small interfering RNA, cyclooxygenase-2 (Cox-2)-defective tumor cells fail to initiate death. Interestingly, the entire phenomena could be reverted back by theaflavins that restore cytokine-dependent IL2Rgammac/Jak-3/Stat-5A signaling in CD4+ T cells thereby protecting them from tumor-shed PGE2-induced apoptosis. CONCLUSIONS/SIGNIFICANCE:These data strongly suggest that tumor-shed PGE2 is an important factor leading to CD4+ T cell apoptosis during cancer and raise the possibility that theaflavins may have the potential as an effective immunorestorer in cancer-bearer

    Prothymosin alpha: a ubiquitous polypeptide with potential use in cancer diagnosis and therapy

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    The thymus is a central lymphoid organ with crucial role in generating T cells and maintaining homeostasis of the immune system. More than 30 peptides, initially referred to as “thymic hormones,” are produced by this gland. Although the majority of them have not been proven to be thymus-speciWc, thymic peptides comprise an eVective group of regulators, mediating important immune functions. Thymosin fraction Wve (TFV) was the Wrst thymic extract shown to stimulate lymphocyte proliferation and diVerentiation. Subsequent fractionation of TFV led to the isolation and characterization of a series of immunoactive peptides/polypeptides, members of the thymosin family. Extensive research on prothymosin (proT) and thymosin 1 (T1) showed that they are of clinical signiWcance and potential medical use. They may serve as molecular markers for cancer prognosis and/or as therapeutic agents for treating immunodeWciencies, autoimmune diseases and malignancies. Although the molecular mechanisms underlying their eVect are yet not fully elucidated proT and T1 could be considered as candidates for cancer immunotherapy. In this review, we will focus in principle on the eventual clinical utility of proT, both as a tumor biomarker and in triggering anticancer immune responses. Considering the experience acquired via the use of T1 to treat cancer patients, we will also discuss potential approaches for the future introduction of proT into the clinical setting

    Immunological control of herpes simplex virus infections

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    Emergence of double-positive CD4/CD8 cells from adult peripheral blood mononuclear cells infected with human T cell leukemia virus type I (HTLV-I)

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    It is known that the human T lymphotropic retrovirus type I (HTLV-I) preferentially selects lymphocytes expressing the CD4 phenotype in vivo and in vitro. The present study shows that the emergence of double-positive (DP) CD4/CD8 cells was a constant, even if transient, phenomenon occurring in early phases after the in vitro HTLV-I infection of adult human peripheral blood mononuclear cells (PBMC). Moreover, purified CD8+ lymphocytes, isolated from human PBMC after challenge with HTLV-I, gave origin to a relatively stable DP CD4/CD8 cell line after a few weeks in culture. Conversely, isolated CD4+ T lymphocytes did not show DP emergence during either the early phases of HTLV-I infection or long-term culture. One of the DP cell lines was maintained in culture for more than 1 year and was characterized on the basis of virological and phenotypic features. This cell line bore HTLV-I sequences as demonstrated by PCR analysis, and 60-90% of the DP cells expressed the virus core protein p19. In addition the phenotype of this DP cell line infected with HTLV-I highly expressed antigens associated to activation such as CD45R0, CD18, and CD54
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