Quenched QCD at finite density

Simulations of quenched $QCD$ at relatively small but {\it nonzero} chemical potential $\mu$ on $32 \times 16^3$ lattices indicate that the nucleon screening mass decreases linearly as $\mu$ increases predicting a critical chemical potential of one third the nucleon mass, $m_N/3$, by extrapolation. The meson spectrum does not change as $\mu$ increases over the same range, from zero to $m_\pi/2$. Past studies of quenched lattice QCD have suggested that there is phase transition at $\mu = m_\pi/2$. We provide alternative explanations for these results, and find a number of technical reasons why standard lattice simulation techniques suffer from greatly enhanced fluctuations and finite size effects for $\mu$ ranging from $m_\pi/2$ to $m_N/3$. We find evidence for such problems in our simulations, and suggest that they can be surmounted by improved measurement techniques.Comment: 23 pages, Revte

Mesenchymal stem cell-derived HGF attenuates radiation-induced senescence in salivary glands via compensatory proliferation

BACKGROUND &amp; AIM: Irradiation of the salivary glands during head and neck cancer treatment induces cellular senescence in response to DNA damage and contributes to radiation-induced hyposalivation by affecting the salivary gland stem/progenitor cell (SGSC) niche. Cellular senescence, such as that induced by radiation, is a state of cell-cycle arrest, accompanied by an altered pro-inflammatory secretome known as the senescence-associated secretory phenotype (SASP) with potential detrimental effects on the surrounding microenvironment. We hypothesized that the pro-regenerative properties of mesenchymal stem cells (MSCs) may attenuate cellular senescence post-irradiation. Therefore, here we evaluated the effects of adipose-derived MSCs (ADSCs) on the radiation-induced response of salivary gland organoids (SGOs).METHODS: Proteomic analyses to identify soluble mediators released by ADSCs co-cultured with SGOS revealed secretion of hepatocyte growth factor (HGF) in ADSCs, suggesting a possible role in the stem cell crosstalk. Next, the effect of recombinant HGF in the culture media of ex vivo grown salivary gland cells was tested in 2D monolayers and 3D organoid models.RESULTS: Treatment with HGF robustly increased salivary gland cell proliferation. Importantly, HGF supplementation post-irradiation enhanced proliferation at lower doses of radiation (0, 3, 7 Gy), but not at higher doses (10, 14 Gy) where most cells stained positive for senescence-associated beta-galactosidase. Furthermore, HGF had no effect on the senescence-associated secretory phenotype (SASP) of irradiated SGOs, suggesting there may be compensatory proliferation by cell-division competent cells instead of a reversal of cellular senescence after irradiation.CONCLUSION: ADSCs may positively influence radiation recovery through HGF secretion and can promote the ex vivo expansion of salivary gland stem/progenitor cells to enhance the effects of co-transplanted SGSC.</p

Mesenchymal stem cell-derived HGF attenuates radiation-induced senescence in salivary glands via compensatory proliferation

BACKGROUND &amp; AIM: Irradiation of the salivary glands during head and neck cancer treatment induces cellular senescence in response to DNA damage and contributes to radiation-induced hyposalivation by affecting the salivary gland stem/progenitor cell (SGSC) niche. Cellular senescence, such as that induced by radiation, is a state of cell-cycle arrest, accompanied by an altered pro-inflammatory secretome known as the senescence-associated secretory phenotype (SASP) with potential detrimental effects on the surrounding microenvironment. We hypothesized that the pro-regenerative properties of mesenchymal stem cells (MSCs) may attenuate cellular senescence post-irradiation. Therefore, here we evaluated the effects of adipose-derived MSCs (ADSCs) on the radiation-induced response of salivary gland organoids (SGOs).METHODS: Proteomic analyses to identify soluble mediators released by ADSCs co-cultured with SGOS revealed secretion of hepatocyte growth factor (HGF) in ADSCs, suggesting a possible role in the stem cell crosstalk. Next, the effect of recombinant HGF in the culture media of ex vivo grown salivary gland cells was tested in 2D monolayers and 3D organoid models.RESULTS: Treatment with HGF robustly increased salivary gland cell proliferation. Importantly, HGF supplementation post-irradiation enhanced proliferation at lower doses of radiation (0, 3, 7 Gy), but not at higher doses (10, 14 Gy) where most cells stained positive for senescence-associated beta-galactosidase. Furthermore, HGF had no effect on the senescence-associated secretory phenotype (SASP) of irradiated SGOs, suggesting there may be compensatory proliferation by cell-division competent cells instead of a reversal of cellular senescence after irradiation.CONCLUSION: ADSCs may positively influence radiation recovery through HGF secretion and can promote the ex vivo expansion of salivary gland stem/progenitor cells to enhance the effects of co-transplanted SGSC.</p

Mesenchymal stem cell-derived HGF attenuates radiation-induced senescence in salivary glands via compensatory proliferation

BACKGROUND &amp; AIM: Irradiation of the salivary glands during head and neck cancer treatment induces cellular senescence in response to DNA damage and contributes to radiation-induced hyposalivation by affecting the salivary gland stem/progenitor cell (SGSC) niche. Cellular senescence, such as that induced by radiation, is a state of cell-cycle arrest, accompanied by an altered pro-inflammatory secretome known as the senescence-associated secretory phenotype (SASP) with potential detrimental effects on the surrounding microenvironment. We hypothesized that the pro-regenerative properties of mesenchymal stem cells (MSCs) may attenuate cellular senescence post-irradiation. Therefore, here we evaluated the effects of adipose-derived MSCs (ADSCs) on the radiation-induced response of salivary gland organoids (SGOs).METHODS: Proteomic analyses to identify soluble mediators released by ADSCs co-cultured with SGOS revealed secretion of hepatocyte growth factor (HGF) in ADSCs, suggesting a possible role in the stem cell crosstalk. Next, the effect of recombinant HGF in the culture media of ex vivo grown salivary gland cells was tested in 2D monolayers and 3D organoid models.RESULTS: Treatment with HGF robustly increased salivary gland cell proliferation. Importantly, HGF supplementation post-irradiation enhanced proliferation at lower doses of radiation (0, 3, 7 Gy), but not at higher doses (10, 14 Gy) where most cells stained positive for senescence-associated beta-galactosidase. Furthermore, HGF had no effect on the senescence-associated secretory phenotype (SASP) of irradiated SGOs, suggesting there may be compensatory proliferation by cell-division competent cells instead of a reversal of cellular senescence after irradiation.CONCLUSION: ADSCs may positively influence radiation recovery through HGF secretion and can promote the ex vivo expansion of salivary gland stem/progenitor cells to enhance the effects of co-transplanted SGSC.</p

The role of the global cryosphere in the fate of organic contaminants

The cryosphere is an important component of global organic contaminant cycles. Snow is an efficient scavenger of atmospheric organic pollutants while a seasonal snowpack, sea ice, glaciers and ice caps are contaminant reservoirs on time scales ranging from days to millennia. Important physical and chemical processes occurring in the various cryospheric compartments impact contaminant cycling and fate. A variety of interactions and feedbacks also occur within the cryospheric system, most of which are susceptible to perturbations due to climate change. In this article, we review the current state of knowledge regarding the transport and processing of organic contaminants in the global cryosphere with an emphasis on the role of a changing climate. Given the complexity of contaminant interactions with the cryosphere and limitations on resources and research capacity, interdisciplinary research and extended collaborations are essential to close identified knowledge gaps and to improve our understanding of contaminant fate under a changing climate

Mesenchymal stem cell-derived HGF attenuates radiation-induced senescence in salivary glands via compensatory proliferation

BACKGROUND &amp; AIM: Irradiation of the salivary glands during head and neck cancer treatment induces cellular senescence in response to DNA damage and contributes to radiation-induced hyposalivation by affecting the salivary gland stem/progenitor cell (SGSC) niche. Cellular senescence, such as that induced by radiation, is a state of cell-cycle arrest, accompanied by an altered pro-inflammatory secretome known as the senescence-associated secretory phenotype (SASP) with potential detrimental effects on the surrounding microenvironment. We hypothesized that the pro-regenerative properties of mesenchymal stem cells (MSCs) may attenuate cellular senescence post-irradiation. Therefore, here we evaluated the effects of adipose-derived MSCs (ADSCs) on the radiation-induced response of salivary gland organoids (SGOs).METHODS: Proteomic analyses to identify soluble mediators released by ADSCs co-cultured with SGOS revealed secretion of hepatocyte growth factor (HGF) in ADSCs, suggesting a possible role in the stem cell crosstalk. Next, the effect of recombinant HGF in the culture media of ex vivo grown salivary gland cells was tested in 2D monolayers and 3D organoid models.RESULTS: Treatment with HGF robustly increased salivary gland cell proliferation. Importantly, HGF supplementation post-irradiation enhanced proliferation at lower doses of radiation (0, 3, 7 Gy), but not at higher doses (10, 14 Gy) where most cells stained positive for senescence-associated beta-galactosidase. Furthermore, HGF had no effect on the senescence-associated secretory phenotype (SASP) of irradiated SGOs, suggesting there may be compensatory proliferation by cell-division competent cells instead of a reversal of cellular senescence after irradiation.CONCLUSION: ADSCs may positively influence radiation recovery through HGF secretion and can promote the ex vivo expansion of salivary gland stem/progenitor cells to enhance the effects of co-transplanted SGSC.</p

Randomized controlled trial of vacuum therapy for intermittent claudication

OBJECTIVE: The "gold standard" treatment of intermittent claudication (IC) is supervised exercise therapy (SET). Intermittent vacuum therapy (IVT) has recently been promoted as an additional treatment of IC. During IVT, negative pressure and atmospheric pressure are alternatingly applied to the lower extremities, possibly resulting in improved circulation. The aim of this study was to determine a potential additional effect of IVT in IC patients undergoing a standardized SET program. METHODS: IC patients were recruited from three Dutch general hospitals between December 2015 and July 2017. They received a standardized SET program but were also randomly assigned to an intervention group receiving an IVT treatment (-50 mBar negative pressure) or a control group receiving a sham treatment (-5 mBar negative pressure). IVT was provided in a dedicated clinic during 12 sessions of 30 minutes during a 6-week period. The primary outcome measure was a change in maximal treadmill walking distance. Secondary outcome measures were a change in functional treadmill walking distance, 6-minute walk test, ambulatory ability, and quality of life. RESULTS: A total of 78 patients were randomized, of whom 70 were available for intention-to-treat analysis (control, n = 34; intervention, n = 36). At 6 and 12 weeks, increases in walking distance were of equal magnitude. Median (interquartile range) change in maximal treadmill walking distance during 12 weeks was +335 (205-756) meters in control patients and +250 (77-466) meters in intervention patients (P = .109), whereas functional treadmill walking distance increased +230 (135-480) meters and +188 (83-389) meters (P = .233), respectively. Mean ± standard deviation change in the 6-minute walk test was +36 ± 48 meters and +55 ± 63 meters (P = .823), respectively. Ambulatory ability and quality of life improved equally in both groups. CONCLUSIONS: IVT does not confer any additional beneficial effects in IC patients undergoing a standardized SET program

Prediction of Dynamic Plasmid Production by Recombinant Escherichia coli Fed-Batch Cultivations with a Generalized Regression Neural Network

A generalized regression neural network with external feedback was used to predict plasmid production in a fed-batch cultivation of recombinant Escherichia coli. The neural network was built out of the experimental data obtained on a few cultivations, of which the general strategy was based on an initial batch phase followed by an exponential feeding phase. The different cultivation conditions used resulted in significant differences in bacterial growth and plasmid production. The obtained model allows estimation of the experimental outputs (biomass, glucose, acetate and plasmid) based on the bioreactor starting conditions and the following on-line inputs: feeding rate, dissolved oxygen concentration and bioreactor stirring speed. Therefore, the proposed methodology presents a quick, simple and reliable way to perform on-line feedback prediction of the dynamic behaviour of the complex plasmid production process, based on simple on-line input data obtained directly from the bioreactor control unit and with few cultivation experiments for neural network learning