1,373 research outputs found
Deconfinement of neutron star matter within the Nambu-Jona-Lasinio model
We study the deconfinement transition of hadronic matter into quark matter
under neutron star conditions assuming color and flavor conservation during the
transition. We use a two-phase description. For the hadronic phase we use
different parameterizations of a non-linear Walecka model which includes the
whole baryon octet. For the quark matter phase we use an SU(3)_f
Nambu-Jona-Lasinio effective model including color superconductivity.
Deconfinement is considered to be a first order phase transition that conserves
color and flavor. It gives a short-lived transitory colorless-quark-phase that
is not in beta-equilibrium, and decays to a stable configuration in tau ~
tau_{weak} ~ 10^{-8} s. However, in spite of being very short lived, the
transition to this intermediate phase determines the onset of the transition
inside neutron stars. We find the transition free-energy density for
temperatures typical of neutron star interiors. We also find the critical mass
above which compact stars should contain a quark core and below which they are
safe with respect to a sudden transition to quark matter. Rather independently
on the stiffness of the hadronic equation of state (EOS) we find that the
critical mass of hadronic stars (without trapped neutrinos) is in the range of
~ 1.5 - 1.8 solar masses. This is in coincidence with previous results obtained
within the MIT Bag model.Comment: 10 pages, 2 figure
Two flavor color superconductivity in nonlocal chiral quark models
We study the competence between chiral symmetry restoration and two flavor
color superconductivity (2SC) using a relativistic quark model with covariant
nonlocal interactions. We consider two different nonlocal regulators: a
Gaussian regulator and a Lorentzian regulator. We find that although the phase
diagrams are qualitative similar to those obtained using models with local
interactions, in our case the superconducting gaps at medium values of the
chemical potential are larger. Consequently, we obtain that in that region the
critical temperatures for the disappearance of the 2SC phase might be of the
order of 100-120 MeV. We also find that for ratios of the quark-quark and
quark-antiquark couplings somewhat above the standard value 3/4, the end point
and triple point in the phase diagram meet and a phase where both the
chiral and diquark condensates are non-negligible appears.Comment: 15 pages incl. 5 Postscript figure
Triglyceride-rich lipoproteins prevent septic death in rats.
Triglyceride-rich lipoproteins bind and inactive bacterial endotoxin in vitro and prevent death when given before a lethal dose of endotoxin in animals. However, lipoproteins have not yet been demonstrated to improve survival in polymicrobial gram-negative sepsis. We therefore tested the ability of triglyceride-rich lipoproteins to prevent death after cecal ligation and puncture (CLP) in rats. Animals were given bolus infusions of either chylomicrons (1 g triglyceride/kg per 4 h) or an equal volume of saline for 28 h after CLP. Chylomicron infusions significantly improved survival (measured at 96 h) compared with saline controls (80 vs 27%, P < or = 0.03). Chylomicron infusions also reduced serum levels of endotoxin, measured 90 min (26 +/- 3 vs 136 +/- 51 pg/ml, mean +/- SEM, P < or = 0.03) and 6 h (121 +/- 54 vs 1,026 +/- 459 pg/ml, P < or = 0.05) after CLP. The reduction in serum endotoxin correlated with a reduction in serum tumor necrosis factor, measured 6 h after CLP (0 +/- 0 vs 58 +/- 24 pg/ml, P < or = 0.03), suggesting that chylomicrons improve survival in this model by limiting macrophage exposure to endotoxin and thereby reducing secretion of inflammatory cytokines. Infusions of a synthetic triglyceride-rich lipid emulsion (Intralipid; KabiVitrum, Inc., Alameda, CA) (1 g triglyceride/kg) also significantly improved survival compared with saline controls (71 vs 27%, P < or = 0.03). These data demonstrate that triglyceride-rich lipoproteins can protect animals from lethal polymicrobial gram-negative sepsis
Effect of supplementary amino acids and adenosine phosphates on motility and metabolism of bovine spermatozoa
This bulletin reports on Department of Dairy Husbandry Research Project 54, Artificial insemination--P. [2].Digitized 2007 AES.Includes bibliographical references (pages 18-20)
Developing clinical decision tools to implement chronic disease prevention and screening in primary care: the BETTER 2 program (building on existing tools to improve chronic disease prevention and screening in primary care).
BackgroundThe Building on Existing Tools to Improve Chronic Disease Prevention and Screening in Family Practice (BETTER) trial demonstrated the effectiveness of an approach to chronic disease prevention and screening (CDPS) through a new skilled role of a 'prevention practitioner'(PP). The PP has appointments with patients 40-65 years of age that focus on primary prevention activities and screening of cancer (breast, colorectal, cervical), diabetes and cardiovascular disease and associated lifestyle factors. There are numerous and occasionally conflicting evidence-based guidelines for CDPS, and the majority of these guidelines are focused on specific diseases or conditions; however, primary care providers often attend to patients with multiple conditions. To ensure that high-level evidence guidelines were used, existing clinical practice guidelines and tools were reviewed and integrated into blended BETTER tool kits. Building on the results of the BETTER trial, the BETTER tools were updated for implementation of the BETTER 2 program into participating urban, rural and remote communities across Canada.MethodsA clinical working group consisting of PPs, clinicians and researchers with support from the Centre for Effective Practice reviewed the literature to update, revise and adapt the integrated evidence algorithms and tool kits used in the BETTER trial. These resources are nuanced, based on individual patient risk, values and preferences and are designed to facilitate decision-making between providers across the target diseases and lifestyle factors included in the BETTER 2 program. Using the updated BETTER 2 toolkit, clinicians 1) determine which CDPS actions patients are eligible to receive and 2) develop individualized 'prevention prescriptions' with patients through shared decision-making and motivational interviewing.ResultsThe tools identify the patients' risks and eligible primary CDPS activities: the patient survey captures the patient's health history; the prevention visit form and integrated CDPS care map identify eligible CDPS activities and facilitate decisions when certain conditions are met; and the 'bubble diagram' and 'prevention prescription' promote shared decision-making.ConclusionThe integrated clinical decision-making tools of BETTER 2 provide resources for clinicians and policymakers that address patients' complex care needs beyond single disease approaches and can be adapted to facilitate CDPS in the urban, rural and remote clinical setting.Trial registrationThe registration number of the original RCT BETTER trial was ISRCTN07170460
Understanding variation in men’s help-seeking for cancer symptoms: a semi-structured interview study
Men appear more likely to delay seeking medical advice for cancer symptoms, resulting in later stage at diagnosis and poorer health outcomes. Limited research has investigated variation in men’s experiences of and responses to cancer symptoms. This study examined the psychosocial aspects of men’s help-seeking for cancer symptoms, as well as potential variation across men residing in urban and rural Australia. Semi-structured interviews were conducted with men recently diagnosed with cancer (n=13). Participants’ partners (n=8) were recruited to enable data triangulation. Interview schedules addressed participants’ pathway to cancer treatment, cancer knowledge, masculinity, and rural living. A theoretical thematic analysis approach was used. Medical help-seeking behaviour was similar for participants residing in urban and rural areas. Five key themes and one sub-theme were identified, including: symptom factors, traditional masculine norms (sub-theme: women’s health-related responsibilities), level of concern, conflicting responsibilities and access, and trust in medical professionals. Participants from rural Australia experienced greater access difficulties and noted optimism regarding symptoms. Results highlight important within-gender differences in the psychosocial barriers to help-seeking for cancer symptoms. Future research should further explore variation between men and test the predictive strength of factors
Options for early breast cancer follow-up in primary and secondary care : a systematic review
Background
Both incidence of breast cancer and survival have increased in recent years and there is a need to review follow up strategies. This study aims to assess the evidence for benefits of follow-up in different settings for women who have had treatment for early breast cancer.
Method
A systematic review to identify key criteria for follow up and then address research questions. Key criteria were: 1) Risk of second breast cancer over time - incidence compared to general population. 2) Incidence and method of detection of local recurrence and second ipsi and contra-lateral breast cancer. 3) Level 1–4 evidence of the benefits of hospital or alternative setting follow-up for survival and well-being. Data sources to identify criteria were MEDLINE, EMBASE, AMED, CINAHL, PSYCHINFO, ZETOC, Health Management Information Consortium, Science Direct. For the systematic review to address research questions searches were performed using MEDLINE (2011). Studies included were population studies using cancer registry data for incidence of new cancers, cohort studies with long term follow up for recurrence and detection of new primaries and RCTs not restricted to special populations for trials of alternative follow up and lifestyle interventions.
Results
Women who have had breast cancer have an increased risk of a second primary breast cancer for at least 20 years compared to the general population. Mammographically detected local recurrences or those detected by women themselves gave better survival than those detected by clinical examination. Follow up in alternative settings to the specialist clinic is acceptable to women but trials are underpowered for survival.
Conclusions
Long term support, surveillance mammography and fast access to medical treatment at point of need may be better than hospital based surveillance limited to five years but further large, randomised controlled trials are needed
Reduction of circulating cholesterol and apolipoprotein levels during sepsis
Sepsis with multiple organ failure is frequently associated with a substantial decrease of cholesterol levels. This decrease of cholesterol is strongly associated with mortality suggesting a direct relation between inflammatory conditions and altered cholesterol homeostasis. The host response during sepsis is mediated by cytokines and growth factors, which are capable of influencing lipid metabolism. Conversely lipoproteins are also capable of modulating cytokine production during the inflammatory response. Therefore the decrease in circulating cholesterol levels seems to play a crucial role in the pathophysiology of sepsis. In this review the interaction between cytokines and lipid metabolism and its clinical consequences will be discussed
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