323 research outputs found

    A Technique of Improved Medial Meniscus Visualization by Anterior Cruciate Ligament Graft Placement in Chronic Anterior Cruciate Deficient Knees

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    It is customary to perform medial meniscus repair before anterior cruciate ligament (ACL) graft placement when undertaken as a combined procedure. However, in chronic ACL-deficient knees, intraoperative anterior tibiofemoral translation can cause the medial meniscus repair to be more technically challenging. Intraoperative anterior tibiofemoral translation can both reduce the visualization of the medial meniscus and make its reduction unstable. An operative sequence alteration of ACL graft placement and tensioning before medial meniscal repair improves medial meniscus visualization in chronically ACL-deficient knees by using the ACL graft’s ability to prevent anterior tibiofemoral translation. The technique sequence is as follows: (a) the medial meniscus is reduced, (b) ACL reconstruction is undertaken using a hamstring graft without final tibia fixation, (c) distal graft tension is manually applied to distal graft sutures by the surgeon to prevent tibiofemoral subluxation, (d) the medial meniscus is repaired while graft tension is applied, and (e) the graft is then fixed to the tibia using an interference screw or another device

    Авария на японской АЭС "Фукусима"

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    В данной статье приведено краткое описание АЭС Фукусима. Рассматривается крупнейшее землетрясение в Японии 2011 года и авария на АЭС Фукусима. Представлена хроника событий аварии, ее ликвидация, а также проанализированы последствия данной аварии. This article provides a brief description of the Fukushima nuclear power plant. It is considered the largest earthquake in Japan 2011 and the accident at the Fukushima nuclear power plant. Presentation of the chronicle of events of the accident, its elimination, as well as analyzed the consequences of the accident

    3D jet writing of mechanically actuated tandem scaffolds

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    The need for high-precision microprinting processes that are controllable, scalable, and compatible with different materials persists throughout a range of biomedical fields. Electrospinning techniques offer scalability and compatibility with a wide arsenal of polymers, but typically lack precise three-dimensional (3D) control. We found that charge reversal during 3D jet writing can enable the high-throughput production of precisely engineered 3D structures. The trajectory of the jet is governed by a balance of destabilizing charge-charge repulsion and restorative viscoelastic forces. The reversal of the voltage polarity lowers the net surface potential carried by the jet and thus dampens the occurrence of bending instabilities typically observed during conventional electrospinning. In the absence of bending instabilities, precise deposition of polymer fibers becomes attainable. The same principles can be applied to 3D jet writing using an array of needles resulting in complex composite materials that undergo reversible shape transitions due to their unprecedented structural control

    Nanoparticleâ Based Targeting and Detection of Microcavities

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/136015/1/adhm201600883.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/136015/2/adhm201600883_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/136015/3/adhm201600883-sup-0001-S1.pd

    Engineered Ovalbumin Nanoparticles for Cancer Immunotherapy

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    Ovalbumin (OVA) is a protein antigen that is widely used for eliciting cellular and humoral immune responses in cancer immunotherapy. As an alternative to solute OVA, engineering approach is developed herein towards protein nanoparticles (pNPs) based on reactive electrospraying. The resulting pNPs are comprised of polymerized OVA, where individual OVA molecules are chemically linked via poly(ethylene glycol) (PEG) units. Controlling the PEG/OVA ratio allows for fine‐tuning of critical physical properties, such as particle size, elasticity, and, at the molecular level, mesh size. As the PEG/OVA ratio decreased, OVA pNPs are more effectively processed by dendritic cells, resulting in higher OT‐I CD8+ cells proliferation in vitro. Moreover, pNPs with lower PEG/OVA ratios elicit enhanced lymphatic drainage in vivo and increased uptake by lymph node macrophages, dendritic cells, and B cells, while 500 nm OVA pNPs show poor draining lymph nodes delivery. In addition, pNPs with lower PEG/OVA ratios result in higher anti‐OVA antibody titers in vivo, suggesting improved humoral immune responses. Importantly, OVA pNPs result in significantly increased median survival relative to solute OVA antigen in a mouse model of B16F10‐OVA melanoma. This work demonstrates that precisely engineered OVA pNPs can improve the overall anti‐tumor response compared to solute antigen.As an alternative to solute antigens for cancer immunotherapy, protein nanoparticles (pNPs) comprised of polymerized antigen linked by poly(ethylene glycol) units are developed based on reactive electrospraying. This engineering approach allows fine tuning the physico‐chemical properties of pNPs such as particle size, elasticity, and mesh size. These properties are related to pNPs enhanced antigen‐specific immune responses and improved anti‐tumor efficacy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163384/3/adtp202000100-sup-0001-SuppMat.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163384/2/adtp202000100.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163384/1/adtp202000100_am.pd

    Chemical vapor deposited polymer layer for efficient passivation of planar perovskite solar cells

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    Reducing non-radiative recombination losses by advanced passivation strategies is pivotal to maximize the power conversion efficiency (PCE) of perovskite solar cells (PSCs). Previously, polymers such as poly(methyl methacrylate), poly(ethylene oxide), and polystyrene were successfully applied in solution-processed passivation layers. However, controlling the thickness and homogeneity of these ultra-thin passivation layers on top of polycrystalline perovskite thin films is a major challenge. In response to this challenge, this work reports on chemical vapor deposition (CVD) polymerization of poly(p-xylylene) (PPX) layers at controlled substrate temperatures (14–16 °C) for efficient surface passivation of perovskite thin films. Prototype double-cation PSCs using a ∼1 nm PPX passivation layer exhibit an increase in open-circuit voltage (VOC_{OC}) of ∼40 mV along with an enhanced fill factor (FF) compared to a non-passivated PSC. These improvements result in a substantially enhanced PCE of 20.4% compared to 19.4% for the non-passivated PSC. Moreover, the power output measurements over 30 days under ambient atmosphere (relative humidity ∼40–50%) confirm that the passivated PSCs are more resilient towards humidity-induced degradation. Considering the urge to develop reliable, scalable and homogeneous deposition techniques for future large-area perovskite solar modules, this work establishes CVD polymerization as a novel approach for the passivation of perovskite thin films

    Molecular dynamics simulations of the growth of poly(chloro-para-xylylene) films

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    Parylene C, poly(chloro-para-xylylene) is the most widely used member of the parylene family due to its excellent chemical and physical properties. In this work we analyzed the formation of the parylene C film using molecular mechanics and molecular dynamics methods. A five unit chain is necessary to create a stable hydrophobic cluster and to adhere to a covered surface. Two scenarios were deemed to take place. The obtained results are consistent with a polymer film scaling growth mechanism and contribute to the description of the dynamic growth of the parylene C polymer

    Immunotherapy for gliomas: shedding light on progress in preclinical and clinical development

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    Gliomas are infiltrating brain tumors associated with high morbidity and mortality. Current standard of care includes radiation, chemotherapy and surgical resection. Today, survival rates for malignant glioma patients remain dismal and unchanged for decades. The glioma microenvironment is highly immunosuppressive and consequently this has motivated the development of immunotherapies for counteracting this condition, enabling the immune cells within the tumor microenvironment to react against this tumor.Areas covered: The authors discuss immunotherapeutic strategies for glioma in phase-I/II clinical trials and illuminate their mechanisms of action, limitations and key challenges. They also examine promising approaches under preclinical development.Expert opinion: In the last decade there has been an expansion in immune-mediated anti-cancer therapies. In the glioma field, sophisticated strategies have been successfully implemented in preclinical models. Unfortunately, clinical trials have not yet yielded consistent results for glioma patients. This could be attributed to our limited understanding of the complex immune cell infiltration and its interaction with the tumor cells, the selected time for treatment, the combination with other therapies and the route of administration of the agent. Applying these modalities to treat malignant glioma is challenging, but many new alternatives are emerging to by-pass these hurdles.Fil: Garcia Fabiani, Maria Belen. University of Michigan; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ventosa, Maria. University of Michigan; Estados UnidosFil: Comba, Andrea. University of Michigan; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Candolfi, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Nicola Candia, Alejandro Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Alghamri, Mahmoud S.. University of Michigan; Estados UnidosFil: Kadiyala, Padma. University of Michigan; Estados UnidosFil: Carney, Stephen. University of Michigan; Estados UnidosFil: Faisal, Syed M.. University of Michigan; Estados UnidosFil: Schwendeman, Anna. University of Michigan; Estados UnidosFil: Moon, James J.. University of Michigan; Estados UnidosFil: Scheetz, Lindsay. University of Michigan; Estados UnidosFil: Lahann, Joerg. University of Michigan; Estados UnidosFil: Mauser, Ava. University of Michigan; Estados UnidosFil: Lowenstein, Pedro R.. University of Michigan; Estados UnidosFil: Castro, Maria Gabriela. University of Michigan; Estados Unido
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