43 research outputs found

    1.3-μm InAs Quantum Dot Lasers with P-type modulation and direct N-type co-doping

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    O-band quantum dot lasers with co-doping reduce threshold current density relative to the undoped case, for 1mm long uncoated lasers from 245Acm-2 to 132Acm-2 at 27°C and 731Acm-2 to 312Acm-2 at 97°C. Improvements are also significant compared to lasers employing any one doping strategy

    Co-doped 1.3μm InAs Quantum Dot Lasers with high gain and low threshold current

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    The mechanism by which co-doping reduces threshold current in O-band Quantum dot lasers is examined, with n-type direct doping of the dots reducing threshold current and p-type modulation doping improving the temperature dependence of threshold current density, relative to undoped samples

    Urinary bicarbonate and metabolic alkalosis during exacerbations in cystic fibrosis

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    The aetiology of increased serum bicarbonate and metabolic alkalosis in CF is complex and appears to be driven, at least in part, by renal tubular CFTR dysfunction https://bit.ly/3NFPkU

    Genital HSV-2 Infection Induces Short-Term NK Cell Memory

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    NK cells are known as innate immune cells that lack immunological memory. Recently, it has been shown that NK cells remember encounters with chemical haptens that induce contact hypersensitivity and cytomegalovirus infection. Here, we show the existence of NK cell memory following HSV-2 infection. Stimulation with HSV-2 Ags led to higher IFNγ production in NK cells that were exposed 30 days previously to HSV-2, compared to NK cells from naïve mice. More importantly, this increased production of IFNγ in NK cells was independent of B- and T- lymphocytes and specific for the HSV-2 Ags. We also showed that previously exposed NK cells in a B- and T-lymphocyte free environment mediate protection against HSV-2 infection and they are necessary for the protection of mice against HSV-2 infection. Collectively, NK cells remember prior HSV-2 encounters independent of B- and T- lymphocytes leading to protection against HSV-2 mediated morbidity and mortality upon re-exposure

    Prolonged Exposure to Progesterone Prevents Induction of Protective Mucosal Responses following Intravaginal Immunization with Attenuated Herpes Simplex Virus Type 2

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    Depo-Provera (Depo) is a long-acting progestational formulation that is a popular form of contraception for women. In animal models of sexually transmitted diseases, it is used to facilitate infection. Here we report that treatment with Depo, in a mouse model of genital herpes simplex virus type 2 (HSV-2), altered immune responses depending on the length of time that animals were exposed to Depo prior to immunization. Mice immunized intravaginally (i.vag.) with an attenuated strain (TK(−)) of HSV-2 following longer (15 days) exposure to Depo (Depo 15 group) failed to show protection when challenged with wild-type HSV-2. In contrast, mice that were immunized shortly after Depo treatment (5 days; Depo 5 group) were fully protected and showed no genital pathology after HSV-2 challenge. High viral titers were detected in the vaginal washes of the Depo 15 group up to 6 days postchallenge. In contrast, no viral shedding was observed beyond day 3 postchallenge in the Depo 5 group. Following i.vag. TK(−) immunization, high levels of gamma interferon (IFN-γ) were detected locally in vaginal washes of the Depo 5 group but not the Depo 15 group. After HSV-2 challenge, an early peak of IFN-γ in the Depo 5 group coincided with clearance of the virus. In Depo 15 animals IFN-γ was present throughout the 6 days postinfection. HSV-2-specific T-cell cytokine responses measured in the lymph node cells of Depo 5 TK(−)-immunized mice indicated a significantly higher Th1 response than that of Depo 15 TK(−)-immunized mice. The protection after HSV-2 challenge in the Depo 5 group correlated with increased local HSV-2 glycoprotein B (gB)-specific immunoglobulin G (IgG) and IgA responses seen in the vaginal secretions. The Depo 15 group had poor gB-specific antibody responses in the genital tract after HSV-2 challenge. These results indicate that longer exposure to Depo leads to poor innate and adaptive immune responses to HSV-2 that fail to protect mice from subsequent genital challenges

    Interleukin-15 modulates adipose tissue by altering mitochondrial mass and activity.

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    Interleukin-15 (IL-15) is an immunomodulatory cytokine that affects body mass regulation independent of lymphocytes; however, the underlying mechanism(s) involved remains unknown. In an effort to investigate these mechanisms, we performed metabolic cage studies, assessed intestinal bacterial diversity and macronutrient absorption, and examined adipose mitochondrial activity in cultured adipocytes and in lean IL-15 transgenic (IL-15tg), overweight IL-15 deficient (IL-15-/-), and control C57Bl/6 (B6) mice. Here we show that differences in body weight are not the result of differential activity level, food intake, or respiratory exchange ratio. Although intestinal microbiota differences between obese and lean individuals are known to impact macronutrient absorption, differing gut bacteria profiles in these murine strains does not translate to differences in body weight in colonized germ free animals and macronutrient absorption. Due to its contribution to body weight variation, we examined mitochondrial factors and found that IL-15 treatment in cultured adipocytes resulted in increased mitochondrial membrane potential and decreased lipid deposition. Lastly, IL-15tg mice have significantly elevated mitochondrial activity and mass in adipose tissue compared to B6 and IL-15-/- mice. Altogether, these results suggest that IL-15 is involved in adipose tissue regulation and linked to altered mitochondrial function
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