558 research outputs found
Electron-hole coexistence in disordered graphene probed by high-field magneto-transport
We report on magneto-transport measurement in disordered graphene under
pulsed magnetic field of up to 57T. For large electron or hole doping, the
system displays the expected anomalous Integer Quantum Hall Effect (IQHE)
specific to graphene up to filling factor . In the close vicinity of the
charge neutrality point, the system breaks up into co-existing puddles of holes
and electrons, leading to a vanishing Hall and finite longitudinal resistance
with no hint of divergence at very high magnetic field. Large resistance
fluctuations are observed near the Dirac point. They are interpreted as the the
natural consequence of the presence of electron and hole puddles. The magnetic
field at which the amplitude of the fluctuations are the largest is directly
linked to the mean size of the puddles
Optimización y revalidación del análisis de nitrógeno por el método
En el presente artículo, se ha optimizado y se ha revalidado el procedimiento de análisis de nitrógeno en muestras de taurina mediante el método Kjeldahl. La Asociación Española de Farmacéuticos de la Industria (AEFI) propone un modelo de cálculo que permite determinar el número de replicados a realizar, en función del coeficiente de variación de la repetibilidad del procedimiento (C.V.%) y el valor límite aceptado, que en el caso de la determinación de la pureza, corresponde al valor máximo o mínimo de las especificaciones de la muestra. Al aplicar dicho modelo, considerando la incertidumbre de calibración del equipo, como el mínimo valor posible para el C.V.%, y teniendo en cuenta las especificaciones establecidas para la taurina en la U.S. Pharmacopeia 30, se obtiene que el número de replicados a realizar es de cinco o seis, según las condiciones de trabajo
Hall effect in the heavy-fermion compound CePtSi
We present Hall-effect measurements on the heavy-fermion compound CePtSi. Above the temperature of antiferromagnetic ordering T_N, the Hall effect of CePtSi exhibits the behavior generally observed in heavy-fermion systems and ascribed to skew scattering. Below T_N the Hall effect is enhanced and its field dependence is strongly nonlinear. We show that this behavior arises from skew scattering or anomalous velocity effects rather than from a change of the ordinary Hall effect induced by a reconstruction of the Fermi surface
Sunitinib Exerts In Vitro Immunomodulatory Activity on Sarcomas via Dendritic Cells and Synergizes With PD-1 Blockade
Background: High-grade sarcomas are a heterogeneous group of aggressive tumors arising in bone and soft tissues. After relapse, treatment options are limited. The multi-targeted receptor tyrosine kinase inhibitors (TKIs) sunitinib and inhibitor of PD-1 (anti-PD-1) nivolumab have shown antitumor activity in selected subtypes. In this study, we examine the role of TKIs and PD-1 based therapy in in vitro cocultures of sarcoma. Methods: The human osteosarcoma (SaOS-2) and synovial sarcoma (SYO-1) cell lines were treated with sunitinib. After cell death and proliferation assessment, expression of PD-L1 was analyzed by flow cytometry. Sunitinib-treated sarcoma cells were cocultured with dendritic cells (DCs), and the phenotype of mature DCs was determined by flow cytometry. Mature DCs were cultured with autologous T cells. PD-1 expression on T cells, their proliferation, T regulatory cell (Tregs) induction and IFN-γ production, before and after nivolumab exposure, were analyzed. Results: Along with its anti-proliferative and direct pro-apoptotic effect on sarcoma cell lines, sunitinib prompted PD-L1 upregulation on sarcoma cells. Interestingly, sunitinib-treated sarcoma cells drive DCs to full maturation and increase their capacity to induce sarcoma-reactive T cells to produce IFN-γ. Conversely, no effect on T cell proliferation and T cell subpopulation composition was observed. Moreover, both bone and synovial sarcoma cell lines induced Tregs through DCs but sunitinib treatment completely abrogated Treg induction. Finally, sarcoma cell lines induced PD-1 upregulation on both effector T cells and Tregs when loaded into DCs, providing a rationale for using PD-1 blockade. Indeed, PD-1 blockade by nivolumab synergized with sunitinib in inducing IFN-γ-producing effector T cells. Conclusions: Taken together, our in vitro data indicate that the treatment of sarcoma cells with sunitinib can exert significant changes on immune cell subsets toward immune activation, leading to DC-based cross-priming of IFN-γ-producing effector T cells and reduced Treg induction. PD-1 blockade with nivolumab has a synergistic effect with sunitinib, supporting the use of TKI and anti-PD-1 approach in sarcomas, and perhaps in other cancers. DC-targeted drugs, including toll-like receptor 3 inhibitors and CD47 inhibitors, are under development and our preclinical model might help to better design their clinical application
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On Automorphisms and Focal Subgroups of Blocks
Given a p-block B of a finite group with defect group P and fusion system on P, we show that the rank of the group is invariant under stable equivalences of Morita type. The main ingredients are the construction, due to Broué and Puig, a theorem of Weiss on linear source modules, arguments of Hertweck and Kimmerle applying Weiss’ theorem to blocks, and connections with integrable derivations in the Hochschild cohomology of block algebras
Storage Life Of Rambutan Packed By Using Microperforated Emap And Cas Techniques For Long Distance Transportation
Ada banyak teknologi untuk meningkatkan umur simpan rambutan, yang merupakan buah non klimakterik, antara lain teknik EMAP (Equillibrium Modified Atmosphere Packaging) dan teknik CA (Controlled Atmosphere). Percobaan laboratorium menggunakan teknik EMAP pada rambutan cv. Binjai dan Lebak Bulus dilakukan dengan menggunakan 4 tingkat jumlah lubang pada LDPE film dengan perforasi mikro: 0, 5, 10, 30 lubang (100 μm) dan stretch film (kontrol supermarket); dikombinasikan dengan suhu penyimpanan (kamar vs 10oC). Sebelum menempatkan buah di ruang penyimpanan 10oC, rambutan telah diadaptasi dengan suhu 15oC selama 24 jam. EMAP 10 perforasi mikro lebih unggul untuk menjaga kesegaran buah hingga 21 hari pada suhu 10oC untuk \u27Binjai\u27 dan \u27Lebak Bulus\u27. Perforasi mikro EMAP 10 yang diterapkan di kontainer yang diangkut udara dari Jakarta ke Belanda (Amsterdam, 40 jam, jarak 11350.64 km) menunjukkan penyimpanan selama 18 hari untuk Binjai dan Lebak Bulus, tetapi hanya 14 hari untuk Rapiah. Penyimpanan lanjutan dengan menggunakan CA, tidak bisa mencapai 30 hari. Oksigen rendah (3 % O2) ditambah CO2 14-17% menunjukkan retensi warna daging yang lebih baik. Dengan demikian, agar tranport udara memungkinkan untuk mengirim rambutan ke Eropa, direkomendasikan menggunakan liner plastic dalam karton dan perlu dikemas dengan EMAP setelah tiba di tujuan
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