Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 73
Filtrar
1.
Sensors (Basel) ; 23(18)2023 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-37766015

RESUMEN

In this work, the degradation of the random telegraph noise (RTN) and the threshold voltage (Vt) shift of an 8.3Mpixel stacked CMOS image sensor (CIS) under hot carrier injection (HCI) stress are investigated. We report for the first time the significant statistical differences between these two device aging phenomena. The Vt shift is relatively uniform among all the devices and gradually evolves over time. By contrast, the RTN degradation is evidently abrupt and random in nature and only happens to a small percentage of devices. The generation of new RTN traps by HCI during times of stress is demonstrated both statistically and on the individual device level. An improved method is developed to identify RTN devices with degenerate amplitude histograms.

2.
Micromachines (Basel) ; 14(7)2023 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-37512740

RESUMEN

The expanded uncertainty of the measured Brillouin scattering shift frequencies is essential in assessing the measurements of parameters of various materials. We describe the general operation principles of a Brillouin light scattering (BLS) spectrometer with a high-power laser and a scanning tandem Fabry-Pérot interferometer (TFPI) for material characterization. Various uncertainty components have been analyzed for the BLS spectrometer following the Guide to the Expression of Uncertainty in Measurement (GUM). The expanded relative uncertainty in the measured Brillouin frequency shift of 15.70 GHz for polymethyl methacrylate (PMMA) was estimated to be 0.26%. The calculated Brillouin frequency shift (based on material properties of PMMA) was determined to be 15.44 GHz with expanded relative uncertainty of 2.13%. It was shown that the measured and calculated Brillouin frequency shifts for PMMA agree within their expanded uncertainties. The TFPI-based BLS spectrometer can be used to measure the longitudinal modulus of materials with an expanded uncertainty of 1.9%, which is smaller than that of the ultrasonic velocity-based method (estimated to be 2.9%).

3.
Nature ; 618(7966): 827-833, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37258670

RESUMEN

The immune phenotype of a tumour is a key predictor of its response to immunotherapy1-4. Patients who respond to checkpoint blockade generally present with immune-inflamed5-7 tumours that are highly infiltrated by T cells. However, not all inflamed tumours respond to therapy, and even lower response rates occur among tumours that lack T cells (immune desert) or that spatially exclude T cells to the periphery of the tumour lesion (immune excluded)8. Despite the importance of these tumour immune phenotypes in patients, little is known about their development, heterogeneity or dynamics owing to the technical difficulty of tracking these features in situ. Here we introduce skin tumour array by microporation (STAMP)-a preclinical approach that combines high-throughput time-lapse imaging with next-generation sequencing of tumour arrays. Using STAMP, we followed the development of thousands of arrayed tumours in vivo to show that tumour immune phenotypes and outcomes vary between adjacent tumours and are controlled by local factors within the tumour microenvironment. Particularly, the recruitment of T cells by fibroblasts and monocytes into the tumour core was supportive of T cell cytotoxic activity and tumour rejection. Tumour immune phenotypes were dynamic over time and an early conversion to an immune-inflamed phenotype was predictive of spontaneous or therapy-induced tumour rejection. Thus, STAMP captures the dynamic relationships of the spatial, cellular and molecular components of tumour rejection and has the potential to translate therapeutic concepts into successful clinical strategies.


Asunto(s)
Neoplasias , Linfocitos T , Microambiente Tumoral , Humanos , Inmunoterapia , Neoplasias/inmunología , Neoplasias/patología , Neoplasias/terapia , Linfocitos T/inmunología , Fenotipo , Fibroblastos , Monocitos , Inhibidores de Puntos de Control Inmunológico/farmacología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico
4.
Micromachines (Basel) ; 15(1)2023 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-38258193

RESUMEN

The MEMS sensor converts the physical signal of nature into an electrical signal. The output signal of the MEMS sensor is so weak and basically in the low-frequency band that the MEMS sensor interface circuit has a rigorous requirement for the noise/offset and temperature coefficient, especially in the bandgap reference block. However, the traditional amplifier has low-frequency noise and offset voltage, which will decrease the precision of the bandgap reference. In order to satisfy the need of the MEMS sensor interface circuit, a high-precision and low-noise bandgap reference is proposed in this paper. A novel operational amplifier with a chopper-stabilization technique is adopted to reduce offset and low-frequency noise. At the same time, the V-curve compensation circuit is used to realize the second-order curvature compensation. The circuit is implemented under the 0.18 µm standard of the CMOS process. The test result shows that the temperature coefficient of the bandgap is 2.31 ppm/°C in the range of -40-140 °C, while the output voltage noise is only 616 nV/sqrt(Hz)@1 Hz and the power-supply rejection ratio is 73 dB@10 kHz. The linear adjustment rate is 0.33 mV/V for supply voltages of 1.2-1.8 V at room temperature, the power consumption is only 107 µW at 1.8 V power supply voltage, and the chip active area is 0.21 × 0.28 mm2.

5.
Arthrosc Tech ; 11(4): e661-e668, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35493038

RESUMEN

Medial meniscus posterior root tears can lead to rapid progression of knee arthritis because of loss of the stress distribution function of the meniscus. Medial meniscus root repair can restore stress distribution and improve clinical outcome. In cases of medial meniscus root tears with meniscal extrusion, centralization may help reduce extrusion and protect the root repair. Presented here is a technique for transtibial medial meniscus root repair with centralization using knotless suture anchors, building on previously developed techniques.

6.
J Cell Biol ; 221(6)2022 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-35446348

RESUMEN

Dendritic cells (DCs) promote adaptive immunity by cross-presenting antigen-based epitopes to CD8+ T cells. DCs process internalized protein antigens into peptides that enter the endoplasmic reticulum (ER), bind to major histocompatibility type I (MHC-I) protein complexes, and are transported to the cell surface for cross-presentation. DCs can exhibit activation of the ER stress sensor IRE1α without ER stress, but the underlying mechanism remains obscure. Here, we show that antigen-derived hydrophobic peptides can directly engage ER-resident IRE1α, masquerading as unfolded proteins. IRE1α activation depletes MHC-I heavy-chain mRNAs through regulated IRE1α-dependent decay (RIDD), curtailing antigen cross-presentation. In tumor-bearing mice, IRE1α disruption increased MHC-I expression on tumor-infiltrating DCs and enhanced recruitment and activation of CD8+ T cells. Moreover, IRE1α inhibition synergized with anti-PD-L1 antibody treatment to cause tumor regression. Our findings identify an unexpected cell-biological mechanism of antigen-driven IRE1α activation in DCs, revealing translational potential for cancer immunotherapy.


Asunto(s)
Reactividad Cruzada , Células Dendríticas , Estrés del Retículo Endoplásmico , Endorribonucleasas , Neoplasias , Proteínas Serina-Treonina Quinasas , Animales , Presentación de Antígeno , Antígenos de Neoplasias/inmunología , Linfocitos T CD8-positivos/inmunología , Células Dendríticas/inmunología , Endorribonucleasas/metabolismo , Antígenos de Histocompatibilidad Clase I/metabolismo , Ratones , Neoplasias/inmunología , Neoplasias/metabolismo , Péptidos/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo
7.
Immunity ; 55(3): 512-526.e9, 2022 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-35263569

RESUMEN

Dual blockade of the PD-1 and TIGIT coinhibitory receptors on T cells shows promising early results in cancer patients. Here, we studied the mechanisms whereby PD-1 and/or TIGIT blockade modulate anti-tumor CD8+ T cells. Although PD-1 and TIGIT are thought to regulate different costimulatory receptors (CD28 and CD226), effectiveness of PD-1 or TIGIT inhibition in preclinical tumor models was reduced in the absence of CD226. CD226 expression associated with clinical benefit in patients with non-small cell lung carcinoma (NSCLC) treated with anti-PD-L1 antibody atezolizumab. CD226 and CD28 were co-expressed on NSCLC infiltrating CD8+ T cells poised for expansion. Mechanistically, PD-1 inhibited phosphorylation of both CD226 and CD28 via its ITIM-containing intracellular domain (ICD); TIGIT's ICD was dispensable, with TIGIT restricting CD226 co-stimulation by blocking interaction with their common ligand PVR (CD155). Thus, full restoration of CD226 signaling, and optimal anti-tumor CD8+ T cell responses, requires blockade of TIGIT and PD-1, providing a mechanistic rationale for combinatorial targeting in the clinic.


Asunto(s)
Linfocitos T CD8-positivos , Neoplasias , Antígenos de Diferenciación de Linfocitos T/metabolismo , Antígenos CD28/metabolismo , Humanos , Neoplasias/metabolismo , Receptor de Muerte Celular Programada 1/metabolismo , Receptores Inmunológicos/metabolismo
8.
Eng Rep ; : e12584, 2022 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-36718396

RESUMEN

By collecting and sorting the energy demand data of developing and developed countries, this paper makes a comprehensive analysis of their energy demand, including the change of energy demand and the change trend of energy load in various sectors. The survey scope of the article includes the overall change trend of energy supply, natural gas, oil, electricity, coal, renewable energy (such as wind energy, solar energy, geothermal energy, tidal energy, etc.), and the data change of global carbon dioxide emission. Besides, this paper selects a variety of energy sources for comprehensive analysis to analyze the existing change trend in chronological order. The analysis methods include data statistics of primary energy production and consumption, energy intensity analysis of gross domestic product (GDP), production, and demand balance of oil, natural gas, and coal, and study the trade balance between different types of energy in different countries and regions. The regions examined in this review include the organization for economic cooperation and development (OECD); the group of seven (G7); Brazil, Russia, India, China and South Africa (BRICs); the European Union; Europe; North America; the Commonwealth of Independent States (CIS); Asia; Latin America; the Pacific Ocean; the Middle East and Africa. By studying these data, we can make a better summary of the current energy use, so as to conveniently grasp the context of energy development and have a general understanding of the current energy structure. Therefore, individuals and policymakers in the fields of energy trade can think more deeply about the future situation and draw conclusions.

9.
Nat Commun ; 12(1): 7310, 2021 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-34911951

RESUMEN

Inositol requiring enzyme 1 (IRE1) mitigates endoplasmic-reticulum (ER) stress by orchestrating the unfolded-protein response (UPR). IRE1 spans the ER membrane, and signals through a cytosolic kinase-endoribonuclease module. The endoribonuclease generates the transcription factor XBP1s by intron excision between similar RNA stem-loop endomotifs, and depletes select cellular mRNAs through regulated IRE1-dependent decay (RIDD). Paradoxically, in mammals RIDD seems to target only mRNAs with XBP1-like endomotifs, while in flies RIDD exhibits little sequence restriction. By comparing nascent and total IRE1α-controlled mRNAs in human cells, we identify not only canonical endomotif-containing RIDD substrates, but also targets without such motifs-degraded by a process we coin RIDDLE, for RIDD lacking endomotif. IRE1α displays two basic endoribonuclease modalities: highly specific, endomotif-directed cleavage, minimally requiring dimers; and more promiscuous, endomotif-independent processing, requiring phospho-oligomers. An oligomer-deficient IRE1α mutant fails to support RIDDLE in vitro and in cells. Our results advance current mechanistic understanding of the UPR.


Asunto(s)
Estrés del Retículo Endoplásmico , Retículo Endoplásmico/metabolismo , Endorribonucleasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Retículo Endoplásmico/genética , Endorribonucleasas/genética , Humanos , Proteínas Serina-Treonina Quinasas/genética , Estabilidad del ARN , ARN Mensajero/genética , ARN Mensajero/metabolismo , Respuesta de Proteína Desplegada
10.
J Immunother Cancer ; 9(10)2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34599029

RESUMEN

BACKGROUND: Individualized neoantigen-specific immunotherapy (iNeST) requires robustly expressed clonal neoantigens for efficacy, but tumor mutational heterogeneity, loss of neoantigen expression, and variable tissue sampling present challenges. It is assumed that clonal neoantigens are preferred targets for immunotherapy, but the distributions of clonal neoantigens are not well characterized across cancer types. METHODS: We combined multiregion sequencing (MR-seq) analysis of five untreated, synchronously sampled metastatic solid tumors with re-analysis of published MR-seq data from 103 patients in order to characterize their globally clonal neoantigen content and factors that would impact neoantigen targeting. RESULTS: Branching evolution in colorectal cancer and renal cell carcinoma led to fewer clonal neoantigens and to clade-specific neoantigens (those shared across a subset of tumor regions but not fully clonal), with the latter not being readily distinguishable in single tumor samples. In colorectal, renal, and bladder cancer, most tumors had few globally clonal neoantigens. Prioritizing mutations with higher purity-adjusted and ploidy-adjusted variant allele frequency enriched for globally clonal neoantigens (those found in all tumor regions), whereas estimated cancer cell fraction derived from clustering-based tools, surprisingly, did not. Neoantigen quality was associated with loss of neoantigen expression in the bladder cancer case, and HLA-allele loss was observed in the renal and non-small cell lung cancer cases. CONCLUSIONS: We show that tumor type, multilesion sampling, neoantigen expression, and HLA allele retention are important factors for iNeST targeting and patient selection, and may also be important factors to consider in the development of biomarker strategies.


Asunto(s)
Antígenos de Neoplasias/inmunología , Biomarcadores de Tumor/metabolismo , Inmunoterapia/métodos , Neoplasias/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Animales , Femenino , Humanos , Masculino , Ratones , Persona de Mediana Edad , Neoplasias/genética
11.
Blood Adv ; 5(17): 3290-3302, 2021 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-34432869

RESUMEN

Replacement of failed organs followed by safe withdrawal of immunosuppressive drugs has long been the goal of organ transplantation. We studied changes in the balance of T cells and myeloid cells in the blood of HLA-matched and -mismatched patients given living donor kidney transplants followed by total lymphoid irradiation, anti-thymocyte globulin conditioning, and donor hematopoietic cell transplant to induce mixed chimerism and immune tolerance. The clinical trials were based on a conditioning regimen used to establish mixed chimerism and tolerance in mice. In preclinical murine studies, there was a profound depletion of T cells and an increase in immunosuppressive polymorphonuclear (pmn) myeloid-derived suppressor cells (MDSCs) in the spleen and blood following transplant. Selective depletion of pmn MDSCs in mice abrogated mixed chimerism and tolerance. In our clinical trials, patients given an analogous tolerance conditioning regimen developed similar changes, including profound depletion of T cells and a marked increase in MDSCs in blood posttransplant. Posttransplant pmn MDSCs transiently increased expression of lectin-type oxidized LDL receptor-1, a marker of immunosuppression, and production of the T-cell inhibitor arginase-1. These posttransplant pmn MDSCs suppressed the activation, proliferation, and inflammatory cytokine secretion of autologous T-cell receptor microbead-stimulated pretransplant T cells when cocultured in vitro. In conclusion, we elucidated changes in receptors and function of immunosuppressive myeloid cells in patients enrolled in the tolerance protocol that were nearly identical to those of MDSCs required for tolerance in mice. These trials were registered at www.clinicaltrials.gov as #NCT00319657 and #NCT01165762.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Animales , Ensayos Clínicos como Asunto , Humanos , Tolerancia Inmunológica , Ratones , Células Mieloides , Receptores de Trasplantes , Acondicionamiento Pretrasplante
12.
J Immunother Cancer ; 9(4)2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33827905

RESUMEN

BACKGROUND: CD8+ tissue-resident memory T (TRM) cells, marked by CD103 (ITGAE) expression, are thought to actively suppress cancer progression, leading to the hypothesis that their presence in tumors may predict response to immunotherapy. METHODS: Here, we test this by combining high-dimensional single-cell modalities with bulk tumor transcriptomics from 1868 patients enrolled in lung and bladder cancer clinical trials of atezolizumab (anti-programmed cell death ligand 1 (PD-L1)). RESULTS: ITGAE was identified as the most significantly upregulated gene in inflamed tumors. Tumor CD103+ CD8+ TRM cells exhibited a complex phenotype defined by the expression of checkpoint regulators, cytotoxic proteins, and increased clonal expansion. CONCLUSIONS: Our analyses indeed demonstrate that the presence of CD103+ CD8+ TRM cells, quantified by tracking intratumoral CD103 expression, can predict treatment outcome, suggesting that patients who respond to PD-1/PD-L1 blockade are those who exhibit an ongoing antitumor T-cell response.


Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Antígenos CD/genética , Antígeno B7-H1/antagonistas & inhibidores , Biomarcadores de Tumor/genética , Linfocitos T CD8-positivos/inmunología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Cadenas alfa de Integrinas/genética , Neoplasias Pulmonares/tratamiento farmacológico , Linfocitos Infiltrantes de Tumor/inmunología , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Anticuerpos Monoclonales Humanizados/efectos adversos , Antígeno B7-H1/inmunología , Ensayos Clínicos Fase II como Asunto , Ensayos Clínicos Fase III como Asunto , Bases de Datos Genéticas , Perfilación de la Expresión Génica , Humanos , Inhibidores de Puntos de Control Inmunológico/efectos adversos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/inmunología , Fenotipo , Ensayos Clínicos Controlados Aleatorios como Asunto , Factores de Tiempo , Resultado del Tratamiento , Microambiente Tumoral , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/inmunología
13.
Sustain Cities Soc ; 73: 103133, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36570018

RESUMEN

In 2020, the COVID-19 pandemic has spread worldwide. To alleviate this spread, various blockade policies have been implemented in many areas. This has led to a sluggish demand in the world's major economies, sharp drop in the trade index, and negative growth in energy consumption. To formulate a better epidemic prevention policy for urban energy consumption of commercial tourism cities, this study summarizes the major statistics of energy supply and demand before and during the epidemic period based on actual data. The characteristics of energy consumption in different sectors, including hotels, transportation, tourism culture, and public utilities, are then analyzed in detail. Finally, the energy consumption features of commercial tourism cities represented by Macao are compared to those of other typical countries (e.g., Italy, United States, Japan, and Brazil). These analyses demonstrate the impact of COVID-19 on the energy consumption in commercial tourism cities, which provides insights for the government or energy providers to formulate policies to adapt to this pandemic.

14.
Cancer Res ; 80(11): 2368-2379, 2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32265225

RESUMEN

Cancer cells exploit the unfolded protein response (UPR) to mitigate endoplasmic reticulum (ER) stress caused by cellular oncogene activation and a hostile tumor microenvironment (TME). The key UPR sensor IRE1α resides in the ER and deploys a cytoplasmic kinase-endoribonuclease module to activate the transcription factor XBP1s, which facilitates ER-mediated protein folding. Studies of triple-negative breast cancer (TNBC)-a highly aggressive malignancy with a dismal posttreatment prognosis-implicate XBP1s in promoting tumor vascularization and progression. However, it remains unknown whether IRE1α adapts the ER in TNBC cells and modulates their TME, and whether IRE1α inhibition can enhance antiangiogenic therapy-previously found to be ineffective in patients with TNBC. To gauge IRE1α function, we defined an XBP1s-dependent gene signature, which revealed significant IRE1α pathway activation in multiple solid cancers, including TNBC. IRE1α knockout in TNBC cells markedly reversed substantial ultrastructural expansion of their ER upon growth in vivo. IRE1α disruption also led to significant remodeling of the cellular TME, increasing pericyte numbers while decreasing cancer-associated fibroblasts and myeloid-derived suppressor cells. Pharmacologic IRE1α kinase inhibition strongly attenuated growth of cell line-based and patient-derived TNBC xenografts in mice and synergized with anti-VEGFA treatment to cause tumor stasis or regression. Thus, TNBC cells critically rely on IRE1α to adapt their ER to in vivo stress and to adjust the TME to facilitate malignant growth. TNBC reliance on IRE1α is an important vulnerability that can be uniquely exploited in combination with antiangiogenic therapy as a promising new biologic approach to combat this lethal disease. SIGNIFICANCE: Pharmacologic IRE1α kinase inhibition reverses ultrastructural distension of the ER, normalizes the tumor vasculature, and remodels the cellular TME, attenuating TNBC growth in mice.


Asunto(s)
Inhibidores de la Angiogénesis/farmacología , Antineoplásicos Inmunológicos/farmacología , Estrés del Retículo Endoplásmico/fisiología , Endorribonucleasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Neoplasias de la Mama Triple Negativas/terapia , Animales , Antineoplásicos Inmunológicos/inmunología , Línea Celular Tumoral , Estrés del Retículo Endoplásmico/efectos de los fármacos , Endorribonucleasas/genética , Femenino , Técnicas de Inactivación de Genes , Humanos , Ratones , Ratones SCID , Neovascularización Patológica/terapia , Proteínas Serina-Treonina Quinasas/genética , ARN Mensajero/genética , Neoplasias de la Mama Triple Negativas/irrigación sanguínea , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/patología , Microambiente Tumoral , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Factor A de Crecimiento Endotelial Vascular/inmunología , Proteína 1 de Unión a la X-Box/antagonistas & inhibidores , Proteína 1 de Unión a la X-Box/genética , Ensayos Antitumor por Modelo de Xenoinjerto
15.
Nature ; 579(7798): 274-278, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32103181

RESUMEN

Despite the resounding clinical success in cancer treatment of antibodies that block the interaction of PD1 with its ligand PDL11, the mechanisms involved remain unknown. A major limitation to understanding the origin and fate of T cells in tumour immunity is the lack of quantitative information on the distribution of individual clonotypes of T cells in patients with cancer. Here, by performing deep single-cell sequencing of RNA and T cell receptors in patients with different types of cancer, we survey the profiles of various populations of T cells and T cell receptors in tumours, normal adjacent tissue, and peripheral blood. We find clear evidence of clonotypic expansion of effector-like T cells not only within the tumour but also in normal adjacent tissue. Patients with gene signatures of such clonotypic expansion respond best to anti-PDL1 therapy. Notably, expanded clonotypes found in the tumour and normal adjacent tissue can also typically be detected in peripheral blood, which suggests a convenient approach to patient identification. Analyses of our data together with several external datasets suggest that intratumoural T cells, especially in responsive patients, are replenished with fresh, non-exhausted replacement cells from sites outside the tumour, suggesting continued activity of the cancer immunity cycle in these patients, the acceleration of which may be associated with clinical response.


Asunto(s)
Linfocitos Infiltrantes de Tumor/citología , Linfocitos Infiltrantes de Tumor/metabolismo , Neoplasias/patología , Variantes Farmacogenómicas , Receptores de Antígenos de Linfocitos T/genética , Linfocitos T/citología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Antineoplásicos/uso terapéutico , Células Clonales , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/inmunología , Linfocitos T/metabolismo , Transcriptoma
16.
ACS Cent Sci ; 5(4): 688-699, 2019 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-31041389

RESUMEN

Quantitatively understanding the self-assembly of amphiphilic macromolecules at liquid-liquid interfaces is a fundamental scientific concern due to its relevance to a broad range of applications including bottom-up nanopatterning, protein encapsulation, oil recovery, drug delivery, and other technologies. Elucidating the mechanisms that drive assembly of amphiphilic macromolecules at liquid-liquid interfaces is challenging due to the combination of hydrophobic, hydrophilic, and Coulomb interactions, which require consideration of the dielectric mismatch, solvation effects, ionic correlations, and entropic factors. Here we investigate the self-assembly of a model block copolymer with various charge fractions at the chloroform-water interface. We analyze the adsorption and conformation of poly(styrene)-block-poly(2-vinylpyridine) (PS-b-P2VP) and of the homopolymer poly(2-vinylpyridine) (P2VP) with varying charge fraction, which is controlled via a quaternization reaction and distributed randomly along the backbone. Interfacial tension measurements show that the polymer adsorption increases only marginally at low charge fractions (<5%) but increases more significantly at higher charge fractions for the copolymer, while the corresponding randomly charged P2VP homopolymer analogues display much more sensitivity to the presence of charged groups. Molecular dynamics (MD) simulations of the experimental systems reveal that the diblock copolymer (PS-b-P2VP) interfacial activity could be mediated by the formation of a rich set of complex interfacial copolymer aggregates. Circular domains to elongated stripes are observed in the simulations at the water-chloroform interface as the charge fraction increases. These structures are shown to resemble the spherical and cylindrical helicoid structures observed in bulk chloroform as the charge fraction increases. The self-assembly of charge-containing copolymers is found to be driven by the association of the charged component in the hydrophilic block, with the hydrophobic segments extending away from the hydrophilic cores into the chloroform phase.

17.
Proc Natl Acad Sci U S A ; 115(50): E11731-E11740, 2018 12 11.
Artículo en Inglés | MEDLINE | ID: mdl-30504141

RESUMEN

Natural killer (NK) cell recognition of tumor cells is mediated through activating receptors such as CD226, with suppression of effector functions often controlled by negative regulatory transcription factors such as FOXO1. Here we show that CD226 regulation of NK cell cytotoxicity is facilitated through inactivation of FOXO1. Gene-expression analysis of NK cells isolated from syngeneic tumors grown in wild-type or CD226-deficient mice revealed dysregulated expression of FOXO1-regulated genes in the absence of CD226. In vitro cytotoxicity and stimulation assays demonstrated that CD226 is required for optimal killing of tumor target cells, with engagement of its ligand CD155 resulting in phosphorylation of FOXO1. CD226 deficiency or anti-CD226 antibody blockade impaired cytotoxicity with concomitant compromised inactivation of FOXO1. Furthermore, inhibitors of FOXO1 phosphorylation abrogated CD226-mediated signaling and effector responses. These results define a pathway by which CD226 exerts control of NK cell responses against tumors.


Asunto(s)
Antígenos de Diferenciación de Linfocitos T/metabolismo , Proteína Forkhead Box O1/antagonistas & inhibidores , Proteína Forkhead Box O1/metabolismo , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Animales , Antígenos de Diferenciación de Linfocitos T/genética , Línea Celular Tumoral , Citotoxicidad Inmunológica , Regulación Neoplásica de la Expresión Génica , Humanos , Ligandos , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Melanoma Experimental/genética , Melanoma Experimental/inmunología , Melanoma Experimental/metabolismo , Ratones , Ratones Noqueados , Nectinas/metabolismo , Fosforilación , Receptores Virales/metabolismo , Transducción de Señal/inmunología
18.
Sensors (Basel) ; 17(12)2017 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-29168778

RESUMEN

A study of the random telegraph noise (RTN) of a 1.1 µm pitch, 8.3 Mpixel CMOS image sensor (CIS) fabricated in a 45 nm backside-illumination (BSI) technology is presented in this paper. A noise decomposition scheme is used to pinpoint the noise source. The long tail of the random noise (RN) distribution is directly linked to the RTN from the pixel source follower (SF). The full 8.3 Mpixels are classified into four categories according to the observed RTN histogram peaks. A theoretical formula describing the RTN as a function of the time difference between the two phases of the correlated double sampling (CDS) is derived and validated by measured data. An on-chip time constant extraction method is developed and applied to the RTN analysis. The effects of readout circuit bandwidth on the settling ratios of the RTN histograms are investigated and successfully accounted for in a simulation using a RTN behavior model.

19.
Cancer Cell ; 31(3): 383-395, 2017 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-28262555

RESUMEN

The anti-FcRH5/CD3 T cell-dependent bispecific antibody (TDB) targets the B cell lineage marker FcRH5 expressed in multiple myeloma (MM) tumor cells. We demonstrate that TDBs trigger T cell receptor activation by inducing target clustering and exclusion of CD45 phosphatase from the synapse. The dimensions of the target molecule play a key role in the efficiency of the synapse formation. The anti-FcRH5/CD3 TDB kills human plasma cells and patient-derived myeloma cells at picomolar concentrations and results in complete depletion of B cells and bone marrow plasma cells in cynomolgus monkeys. These data demonstrate the potential for the anti-FcRH5/CD3 TDB, alone or in combination with inhibition of PD-1/PD-L1 signaling, in the treatment of MM and other B cell malignancies.


Asunto(s)
Anticuerpos Biespecíficos/uso terapéutico , Complejo CD3/inmunología , Epítopos , Sinapsis Inmunológicas/fisiología , Mieloma Múltiple/tratamiento farmacológico , Receptores Fc/inmunología , Linfocitos T/inmunología , Animales , Citocinas/metabolismo , Humanos , Antígenos Comunes de Leucocito/fisiología , Activación de Linfocitos , Macaca fascicularis , Ratones , Mieloma Múltiple/inmunología , Mieloma Múltiple/patología , Receptor de Muerte Celular Programada 1/fisiología , Receptores de Antígenos de Linfocitos T/fisiología , Receptores Fc/análisis
20.
R Soc Open Sci ; 3(9): 160273, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27703690

RESUMEN

Our sense of depth perception is mediated by spatial filters at different scales in the visual brain; low spatial frequency channels provide the basis for coarse stereopsis, whereas high spatial frequency channels provide for fine stereopsis. It is well established that monocular blurring of vision results in decreased stereoacuity. However, previous studies have used tests that are broadband in their spatial frequency content. It is not yet entirely clear how the processing of stereopsis in different spatial frequency channels is altered in response to binocular input imbalance. Here, we applied a new stereoacuity test based on narrow-band Gabor stimuli. By manipulating the carrier spatial frequency, we were able to reveal the spatial frequency tuning of stereopsis, spanning from coarse to fine, under blurred conditions. Our findings show that increasing monocular blur elevates stereoacuity thresholds 'selectively' at high spatial frequencies, gradually shifting the optimum frequency to lower spatial frequencies. Surprisingly, stereopsis for low frequency targets was only mildly affected even with an acuity difference of eight lines on a standard letter chart. Furthermore, we examined the effect of monocular blur on the size tuning function of stereopsis. The clinical implications of these findings are discussed.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...