6,895 research outputs found
Volume-energy correlations in the slow degrees of freedom of computer-simulated phospholipid membranes
Constant-pressure molecular-dynamics simulations of phospholipid membranes in
the fluid phase reveal strong correlations between equilibrium fluctuations of
volume and energy on the nanosecond time-scale. The existence of strong
volume-energy correlations was previously deduced indirectly by Heimburg from
experiments focusing on the phase transition between the fluid and the ordered
gel phases. The correlations, which are reported here for three different
membranes (DMPC, DMPS-Na, and DMPSH), have volume-energy correlation
coefficients ranging from 0.81 to 0.89. The DMPC membrane was studied at two
temperatures showing that the correlation coefficient increases as the phase
transition is approached
Isomorphs in model molecular liquids
Isomorphs are curves in the phase diagram along which a number of static and
dynamic quantities are invariant in reduced units. A liquid has good isomorphs
if and only if it is strongly correlating, i.e., the equilibrium
virial/potential energy fluctuations are more than 90% correlated in the NVT
ensemble. This paper generalizes isomorphs to liquids composed of rigid
molecules and study the isomorphs of two systems of small rigid molecules, the
asymmetric dumbbell model and the Lewis-Wahnstrom OTP model. In particular, for
both systems we find that the isochoric heat capacity, the excess entropy, the
reduced molecular center-of-mass self part of the intermediate scattering
function, the reduced molecular center-of-mass radial distribution function to
a good approximation are invariant along an isomorph. In agreement with theory,
we also find that an instantaneous change of temperature and density from an
equilibrated state point to another isomorphic state point leads to no
relaxation. The isomorphs of the Lewis-Wahnstrom OTP model were found to be
more approximative than those of the asymmetric dumbbell model, which is
consistent with the OTP model being less strongly correlating. For both models
we find "master isomorphs", i.e., isomorphs have identical shape in the
virial/potential energy phase diagram.Comment: 20 page
Health care providersâ perspectives on the content and structure of a culturally tailored antenatal care programme to expectant parents and family members in Nepal.
Background: In Nepal childbirth is one of the most vulnerable periods of a woman's life and knowledge about the normal birth process, as well as danger signs, could be a life-saving intervention. Antenatal care programmes are therefore particularly relevant in Nepal where women deliver on their own in rural areas as well as in facility and hospital settings. Aim: This study aimed to describe the relevant content and structure of a culturally tailored antenatal care programme in Nepal to be developed from the input of healthcare providers. Methods: Qualitative semi-structured interviews with 26 health care providers were analyzed using Elo and Kyngäsâ content analysis. This study received ethical approval from the research ethics committee at Dalarna University, Sweden, and the Nepal Health Research Council. Findings: The results present possible (1) content and (2) structure of a culturally tailored antenatal care programme. Content is comprised of (a) how pregnancy affects the mother and how her lifestyle affects the unborn child; (b) normal childbirth, complications, and preparations; and (c) postpartum period â parenthood, childcare, and breastfeeding. Structure is related to (a) programme leader and location; (b) participants; and (c) pedagogy. Conclusion: This antenatal care programme will be culturally tailored to empower women with self-confidence and their decision-making power may increase in the family system regarding their own and their childrenâs health and wellbeing. Clinical Application: This study can help those designing culturally sensitive antenatal care programs in Nepal
Plasma level of mannose-binding lectin is associated with the risk of recurrent pregnancy loss but not pregnancy outcome after the diagnosis
STUDY QUESTION: Are low or high plasma mannose-binding lectin (p-MBL) levels associated with recurrent pregnancy loss (RPL) and the reproductive and perinatal outcomes before and after RPL? SUMMARY ANSWER: The prevalence of low p-MBL levels was significantly higher in RPL patients, while high levels were significantly less prevalent. No association was found between p-MBL level and reproductive and perinatal outcomes before and after RPL. WHAT IS KNOWN ALREADY: Mannose-binding lectin (MBL) is an important component in the innate immune system. Low p-MBL levels have been associated with RPL, while the correlation with high levels has been poorly studied. Adverse perinatal outcomes are generally more frequent among RPL patients, but reports concerning the association between maternal p-MBL levels and perinatal outcomes, including birth weight (BW) and gestational age (GA), are conflicting. STUDY DESIGN, SIZE, DURATION: This study was a combined cross-sectional and cohort study of 267 RPL patients admitted to the RPL Center of Western Denmark between January 2016 and March 2020. RPL patients were followed until birth of a liveborn child or until end of follow-up, March 2021. A sample of 185 healthy female blood donors of reproductive age was used as a MBL reference group. PARTICIPANTS/MATERIALS, SETTING, METHODS: All RPL patients had âĽ3 consecutive pregnancy losses, a regular menstrual cycle and no known significant chromosomal or uterine malformations. At the first consultation, routine blood samples including p-MBL measurement and detailed obstetrical and perinatal information were collected. p-MBL levels in RPL patients were compared to the MBL reference group. A logistic regression analysis adjusted for relevant confounders assessed the association between low p-MBL levels and an unsuccessful reproductive outcome in RPL patients in first pregnancy after admission. Perinatal outcomes before and after RPL were compared between RPL subgroups according to low (â¤500âÂľg/l), intermediate (501â3000âÂľg/l) and high (>3000âÂľg/l) p-MBL levels. MAIN RESULTS AND THE ROLE OF CHANCE: Significantly more RPL patients had low p-MBL levels (prevalence proportion ratio (PPR): 1.79, 95% CI: 1.34â2.38) and fewer had high p-MBL levels (PPR: 0.56, 95% CI: 0.40â0.79) compared to the reference group, while the prevalence of intermediate p-MBL level was not different between the groups (PPR: 0.86, 95% CI: 0.69â1.08). In the prospective study, low p-MBL level was not a significant risk factor for a pregnancy loss in the first pregnancy after admission after adjustment for age, BMI and smoking. Neither before nor after the RPL diagnosis were maternal p-MBL levels significantly associated with BW or GA. LIMITATIONS, REASONS FOR CAUTION: Only 161 (60.3%) patients had given birth after RPL during the follow-up period, which limited the possibility to detect clear associations between p-MBL levels and perinatal outcomes after RPL. WIDER IMPLICATIONS OF THE FINDINGS: In agreement with several previous studies, low p-MBL levels are strongly associated with RPL, while this study for the first time documents that high levels may play a protective role, which suggests a causal relationship. We suggest that larger prospective studies evaluate the association between p-MBL levels and RPL prognosis. STUDY FUNDING/COMPETING INTEREST(S): No external funding was received. We acknowledge the Department of Obstetrics and Gynaecology at Aalborg University Hospital for financial support. U.S.K. has reported personal fees from Merck, consulting fees from IBSA Nordic, and a grant from Gedeon Richter, Merck and IBSA Nordic outside of the submitted work. TRIAL REGISTRATION NUMBER: ID from clinicaltrials.gov is NCT04017754
The relationship between HbA1c and hypoglycaemia in patients with diabetes treated with insulin degludec versus insulin glargine 100âunits/mL
Aim
Treatâtoâtarget, randomized controlled trials have confirmed lower rates of hypoglycaemia at equivalent glycaemic control with insulin degludec (degludec) versus insulin glargine 100 units/mL (glargine U100) in patients with type 1 (T1D) or type 2 diabetes (T2D). Treatâtoâtarget trials are designed to enable comparisons of safety and tolerability at a similar HbA1c level. In this post hoc analysis of the SWITCH 1 and 2 trials, we utilised a patientâlevel modelling approach to compare how glycaemic control might differ between basal insulins at a similar rate of hypoglycaemia.
Materials and Methods
Data for HbA1c and symptomatic hypoglycaemia from the SWITCH 1 and SWITCH 2 trials were analyzed separately for patients with type 1 diabetes and type 2 diabetes, respectively. The association between the individual patientâlevel risk of hypoglycaemia and HbA1c was investigated using a Poisson regression model and used to estimate potential differences in glycaemic control with degludec versus glargine U100, at the same rate of hypoglycaemia.
Results
Improvements in glycaemic control increased the incidence of hypoglycaemia with both basal insulins across diabetes types. Our analysis suggests that patients could achieve a mean HbA1c reduction of 0.70 [0.05; 2.20]95% CI (for type 1 diabetes) or 0.96 [0.39; 1.99]95% CI (for type 2 diabetes) percentage points (8 [1; 24]95% CI or 10 [4; 22]95% CI mmol/mol, respectively) further with degludec than with glargine U100 before incurring an equivalent risk of hypoglycaemia.
Conclusion
Our findings suggest that patients in clinical practice may be able to achieve lower glycaemia targets with degludec versus glargine U100, before incurring an equivalent risk of hypoglycaemia
Excitons in type-II quantum dots: Finite offsets
Quantum size effects for an exciton attached to a spherical quantum dot are
calculated by a variational approach. The band line-ups are assumed to be
type-II with finite offsets. The dependence of the exciton binding energy upon
the dot radius and the offsets is studied for different sets of electron and
hole effective masses
Vortices and Quantum tunneling in Current-Biased 0-\pi-0 Josephson Junctions of d-wave Superconductors
We study a current-biased 0-\pi-0 Josephson junction made by high-T_c
superconductors, theoretically. When a length of the \pi junction is large
enough, this junction contains a vortex-antivortex pair at both ends of the \pi
junction. Magnetic flux carried by the vortices is calculated using the
sine-Gordon equation. The result shows that the magnetic flux of the vortices
is suppressed to zero as the distance between the vortices is reduced. By
applying an external current, the orientation of the vortices is reversed, and
a voltage pulse is generated. The current needed for this transition and
generated pulse energy are calculated. Macroscopic quantum tunneling (MQT) in
this transition is also studied. The tunneling rate has been evaluated by an
effective Hamiltonian with one degree of freedom.Comment: 12 pages, LaTeX with 5 PS figures, using jpsj.st
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