Clinical Characteristics of Hyponatremia

Background & aims : We investigated the contributing factors of hyponatremia in patients on nutrition support using bioelectrical impedance analysis (BIA). Methods : Thirty patients administered enteral or parenteral nutrition support for at least 72 hours were studied. We collected nutritional and electrolyte intake, serum biochemical parameters, and body composition measured by BIA. Patients were classified into two groups according to their serum sodium levels : (1) Normanatremia group, 135–145 mEq / L (n = 18) and (2) Hyponatremia group, less than 135 mEq / L (n = 12), and their characteristics were analyzed. Results : There were no significant differences between the Normonatremia and Hyponatremia groups in terms of energy, protein, and sodium intake. Serum biochemical parameters other than serum sodium and chloride levels were comparable between the two groups. On the other hand, the ratio of extracellular water to total body water (ECW / TBW) obtained by BIA was significantly higher in the Hyponatremia group than in the Normonatremia group. Further, an elevated ECW / TBW significantly and negatively correlated with serum albumin level. Conclusions : Regardless of sodium intake, higher ECW / TBW was associated with hyponatremia in patients on nutrition support. ECW / TBW may be an important clinical parameter relevant to the nutritional care of hyponatremia

KMT-2021-BLG-1150Lb: Microlensing planet detected through a densely covered planetary-caustic signal

Recently, there have been reports of various types of degeneracies in the interpretation of planetary signals induced by planetary caustics. In this work, we check whether such degeneracies persist in the case of well-covered signals by analyzing the lensing event KMT-2021-BLG-1150, for which the light curve exhibits a densely and continuously covered short-term anomaly. In order to identify degenerate solutions, we thoroughly investigate the parameter space by conducting dense grid searches for the lensing parameters. We then check the severity of the degeneracy among the identified solutions. We identify a pair of planetary solutions resulting from the well-known inner-outer degeneracy, and find that interpreting the anomaly is not subject to any degeneracy other than the inner-outer degeneracy. The measured parameters of the planet separation (normalized to the Einstein radius) and mass ratio between the lens components are $(s, q)_{\rm in}\sim (1.297, 1.10\times 10^{-3})$ for the inner solution and $(s, q)_{\rm out}\sim (1.242, 1.15\times 10^{-3})$ for the outer solution. According to a Bayesian estimation, the lens is a planetary system consisting of a planet with a mass $M_{\rm p}=0.88^{+0.38}_{-0.36}~M_{\rm J}$ and its host with a mass $M_{\rm h}=0.73^{+0.32}_{-0.30}~M_\odot$ lying toward the Galactic center at a distance $D_{\rm L} =3.8^{+1.3}_{-1.2}$~kpc. By conducting analyses using mock data sets prepared to mimic those obtained with data gaps and under various observational cadences, it is found that gaps in data can result in various degenerate solutions, while the observational cadence does not pose a serious degeneracy problem as long as the anomaly feature can be delineated.Comment: 9 pages, 8 figure

KMT-2022-BLG-0440Lb: A New q<10−4q < 10^{-4} Microlensing Planet with the Central-Resonant Caustic Degeneracy Broken

We present the observations and analysis of a high-magnification microlensing planetary event, KMT-2022-BLG-0440, for which the weak and short-lived planetary signal was covered by both the KMTNet survey and follow-up observations. The binary-lens models with a central caustic provide the best fits, with a planet/host mass ratio, $q = 0.75$--$1.00 \times 10^{-4}$ at $1\sigma$. The binary-lens models with a resonant caustic and a brown-dwarf mass ratio are both excluded by $\Delta\chi^2 > 70$. The binary-source model can fit the anomaly well but is rejected by the ``color argument'' on the second source. From Bayesian analyses, it is estimated that the host star is likely a K or M dwarf located in the Galactic disk, the planet probably has a Neptune-mass, and the projected planet-host separation is $1.9^{+0.6}_{-0.7}$ or $4.6^{+1.4}_{-1.7}$ au, subject to the close/wide degeneracy. This is the third $q < 10^{-4}$ planet from a high-magnification planetary signal ($A \gtrsim 65$). Together with another such planet, KMT-2021-BLG-0171Lb, the ongoing follow-up program for the KMTNet high-magnification events has demonstrated its ability in detecting high-magnification planetary signals for $q < 10^{-4}$ planets, which are challenging for the current microlensing surveys.Comment: MNRAS accepte

KMT-2023-BLG-1431Lb: A New q<10−4q < 10^{-4} Microlensing Planet from a Subtle Signature

The current studies of microlensing planets are limited by small number statistics. Follow-up observations of high-magnification microlensing events can efficiently form a statistical planetary sample. Since 2020, the Korea Microlensing Telescope Network (KMTNet) and the Las Cumbres Observatory (LCO) global network have been conducting a follow-up program for high-magnification KMTNet events. Here, we report the detection and analysis of a microlensing planetary event, KMT-2023-BLG-1431, for which the subtle (0.05 magnitude) and short-lived (5 hours) planetary signature was characterized by the follow-up from KMTNet and LCO. A binary-lens single-source (2L1S) analysis reveals a planet/host mass ratio of $q = (0.72 \pm 0.07) \times 10^{-4}$, and the single-lens binary-source (1L2S) model is excluded by $\Delta\chi^2 = 80$. A Bayesian analysis using a Galactic model yields estimates of the host star mass of $M_{\rm host} = 0.57^{+0.33}_{-0.29}~M_\odot$, the planetary mass of $M_{\rm planet} = 13.5_{-6.8}^{+8.1}~M_{\oplus}$, and the lens distance of $D_{\rm L} = 6.9_{-1.7}^{+0.8}$ kpc. The projected planet-host separation of $a_\perp = 2.3_{-0.5}^{+0.5}$ au or $a_\perp = 3.2_{-0.8}^{+0.7}$, subject to the close/wide degeneracy. We also find that without the follow-up data, the survey-only data cannot break the degeneracy of central/resonant caustics and the degeneracy of 2L1S/1L2S models, showing the importance of follow-up observations for current microlensing surveys.Comment: PASP submitted. arXiv admin note: text overlap with arXiv:2301.0677

OGLE-2019-BLG-0825: Constraints on the Source System and Effect on Binary-lens Parameters arising from a Five Day Xallarap Effect in a Candidate Planetary Microlensing Event

We present an analysis of microlensing event OGLE-2019-BLG-0825. This event was identified as a planetary candidate by preliminary modeling. We find that significant residuals from the best-fit static binary-lens model exist and a xallarap effect can fit the residuals very well and significantly improves $\chi^2$ values. On the other hand, by including the xallarap effect in our models, we find that binary-lens parameters like mass-ratio, $q$, and separation, $s$, cannot be constrained well. However, we also find that the parameters for the source system like the orbital period and semi major axis are consistent between all the models we analyzed. We therefore constrain the properties of the source system better than the properties of the lens system. The source system comprises a G-type main-sequence star orbited by a brown dwarf with a period of $P\sim5$ days. This analysis is the first to demonstrate that the xallarap effect does affect binary-lens parameters in planetary events. It would not be common for the presence or absence of the xallarap effect to affect lens parameters in events with long orbital periods of the source system or events with transits to caustics, but in other cases, such as this event, the xallarap effect can affect binary-lens parameters.Comment: 19 pages, 7 figures, 6 tables. Accepted by A

Low lung diffusing capacity is associated with high cardio-ankle vascular index in patients with chronic obstructive pulmonary disease

Previous studies have demonstrated that arterial stiffness is independently associated with the severity of pulmonary emphysema observed on computed tomography (CT) in patients with chronic obstructive pulmonary disease (COPD). An inverse correlation exists between emphysema severity on CT image and lung diffusing capacity; however, the relationship between lung diffusing capacity and arterial stiffness in patients with COPD remains unclear. We retrospectively analyzed the data of 30 patients with COPD. Percent predicted diffusing capacity of the lung for carbon monoxide divided by alveolar volume (%DLco/VA) was used as an index of lung diffusing capacity. We used the Goddard score as an index of the severity of pulmonary emphysema on CT image and cardio-ankle vascular index (CAVI) as an index of arterial stiffness. CAVI was inversely correlated with %DLco/VA (r = −0.539, p = 0.002) but not correlated with Goddard score (rs = 0.236, p = 0.209). None of the other respiratory parameters investigated, including forced expiratory volume in the first second (FEV1), FEV1/forced vital capacity ratio, and percent predicted FEV1, were correlated with CAVI. In multiple regression analysis, systolic blood pressure (β = 0.404, p = 0.006), %DLco/VA (β = −0.379, p = 0.012), and modified Borg scale score for dyspnea (β = 0.304, p = 0.033) were significant predictors of CAVI. Lung diffusing capacity is a significant independent predictor of arterial stiffness in patients with COPD. The evaluation of %DLco/VA in patients with COPD might be useful for predicting high CAVI and the development of cardiovascular disease in the future

DNA G-Wire Formation Using an Artificial Peptide is Controlled by Protease Activity

The development of a switching system for guanine nanowire (G-wire) formation by external signals is important for nanobiotechnological applications. Here, we demonstrate a DNA nanostructural switch (G-wire particles) using a designed peptide and a protease. The peptide consists of a PNA sequence for inducing DNA to form DNA–PNA hybrid G-quadruplex structures, and a protease substrate sequence acting as a switching module that is dependent on the activity of a particular protease. Micro-scale analyses via TEM and AFM showed that G-rich DNA alone forms G-wires in the presence of Ca2+, and that the peptide disrupted this formation, resulting in the formation of particles. The addition of the protease and digestion of the peptide regenerated the G-wires. Macro-scale analyses by DLS, zeta potential, CD, and gel filtration were in agreement with the microscopic observations. These results imply that the secondary structure change (DNA G-quadruplex DNA/PNA hybrid structure) induces a change in the well-formed nanostructure (G-wire particles). Our findings demonstrate a control system for forming DNA G-wire structures dependent on protease activity using designed peptides. Such systems hold promise for regulating the formation of nanowire for various applications, including electronic circuits for use in nanobiotechnologies