Hyponatremia in the outpatient setting: clinical characteristics, risk factors, and outcome

Purpose Hyponatremia is a common disorder and hyponatremia in the outpatient setting is not extensively studied. Our aim was to investigate the characteristics of hyponatremia in ambulatory patients. Methods Seventy-six adult outpatients with hyponatremia were enrolled in this prospective study. Demographic features, presenting symptoms and signs, associating morbidities, medications, laboratory findings, mortalities, and length of hospital stay, were recorded. Results Mean age was 74.7 ± 12.7 years, and 52 (68.4 %) were female whereas 24 (31.6 %) were male. Mean sodium concentration was 123.6 ± 6.6 mEq/L. Leading cause was thiazide diuretic use (n = 37, 48.7 %) and approximately half of the patients (n = 40, 52.6 %) had a multifactorial etiology. Severe hyponatremia (sodium < 125 mEq/L) was identified in 37 (48.7 %). Thiazide diuretic use, vomiting, and apathy were independent predictors of severe hyponatremia. Eight (10.5 %) patients had a mortal course. A relatively younger age, male gender, presenting sign of lethargy, associating morbidities of malignancy, chronic liver disease, and hypoalbuminemia were risk factors for mortality. Conclusions Hyponatremia is prevalent among elderly, especially in women and with thiazide diuretics. Apart from the trend toward sodium depletion observed in healthy elderly which occurs due to changes in the tubular handling of sodium, a multifactorial etiology including thiazides seems to predict the occurrence and the severity of hyponatremia. Hyponatremia may be a significant cause of mortality in seniors. A relatively younger age, male gender, association of cirrhosis, malignancy, and hypoalbuminemia predict mortality. In elderly outpatients, identification of the risk factors for hyponatremia and close monitoring are imperative to reduce the related mortality and morbidity

D-STATCOM design and analysis for improving power quality in micro grids

Gelişen teknolojiyle birlikte, endüstriyel uygulamalarda kullanılan yüklerin büyük bir kısmı endüktif yüklerden oluşmaktadır. Endüktif yükler, yapıları gereği endüktif reaktif enerji tüketmektedirler. Tüketilen bu reaktif enerji, sistemin kalitesinde ve verimliliğinde düşüşe ve güç faktöründe sorunlara neden olmaktadır. Esnek alternatif akım iletim sistemleri (FACTS), güç sisteminin performansını ve kalitesini arttırmada önemli bir rol oynamaktadır. FACTS sistemiyle donatılmış bir güç sisteminin kontrolü daha hızlı ve kolaydır. Dağıtım Statik Senkron Kompansatör (D-STATCOM), güç kalitesini arttırmak için kullanılan en yaygın FACTS cihazıdır. Reaktif güç kontrolü içinde kullanılan D-STATCOM, dağıtım sistemlerinde güç kalitesini arttırmak için kullanılan şönt bağlı bir cihazdır. D-STATCOM şebeke ile reaktif güç alış verişinde bulunarak, gerilim dalgalanmalarını önler. Bu çalışmada şebekelerde güç kalitesini arttırmak için Matlab/Simulink programı kullanılarak D-STATCOM modellemesi yapılmış ve benzetim sonuçları incelenmiştir. Modellenen sistemde, iki ayrı test yükü kullanılmıştır. Bu yüklerin dağıtım hattında meydana getirdiği güç kalitesi problemleri ise modellenen D-STATCOM aracılığıyla giderilmeye çalışılmıştır. Yapılan benzetime göre, D-STATCOM şebekeye bağlandığında, sistemdeki gerilim dalgalanmasının ve toplam harmonik distorisyonunun (THD) büyük oranda azaldığı doğrulanmış ve D-STATCOM'un şebekedeki değişken yüklerin neden olduğu gerilim artışını veya çökmesini büyük ölçüde giderdiği görülmüştür.The current industrial applications are based on inductive loads due to developing technology. The inductive loads consume inductive reactive energy owing to their electrical structures. The consumed reactive energy causes to decrease in power quality and efficiency of the system in addition to power factor deficiencies. The flexible alternating current transmission systems (FACTS) play an important role in improving the performance and quality of the power system. The control of power systems that are equipped with FACTS systems are accomplied faster and easier comparing to regular compensations. The Distribution Static Synchronous Compensator (D-STATCOM) is the most common FACTS device used to increase power quality. D-STATCOM, also used for reactive power control, is a shunt connected device which is used to improve power quality in distribution systems. D-STATCOM exchanges reactive power with mains and prevents voltage fluctuations. In this study, D-STATCOM modeling has been performed in order to improve the power quality in grids by using Matlab/Simulink software and the simulation results were examined. Two separete test loads were used in the modeled system. The power quality problems caused by these loads on the distribution line were tried to be eliminated through the modeled D-STATCOM. According to the simulation results, it is confirmed that the voltage fluctuation and total harmonic distortion (THD) on the load side are remarkably reduced when the D-SATCOM is connected to the network and D-STATCOM has been seen to greatly improve the voltage rise or sagging caused by variable loads in the network

Influence of time and direction information on video head impulse gains

WOS: 000422985600015PubMed ID: 28716764OBJECTIVE: The objective of this study was to establish which factor leads to a higher vestibulo-ocular reflex (VOR) gain: the timing of the movement or the direction of the movement. For this purpose, healthy volunteers were examined under three conditions: (1) when they were informed about the timing of the head movement; (2) when they were informed about the direction of the head movement; and (3) when they knew both the timing and the direction of the head movement. MATERIALS and METHODS: This study included data from 19 participants between the ages of 20 and 23 years with no neurological or vestibular ailments. The gains of the video head impulse test (vHIT) were measured under four different conditions and the final control tests. Five subgroups were defined, and the differences in the subgroups were assessed with using several statistical procedures. RESULTS: We found that there were significant differences between all subgroups gains on the right and left head rotations. Nevertheless, nonsignificant differences were found by performing independent samples t-tests and Mann-Whitney U tests between left and right head rotations for the pairwise comparisons of subgroups. Also, analysis of variance (ANOVA) results indicated that vHIT gains for the right and left, respectively). Thus, knowing the timing or direction or both does not affect vHIT gains. CONCLUSION: The results of these experiments revealed that there is no association whatsoever between VOR gain and awareness of the timing or direction of the movement or both