Disabling Wake Up Stroke without Lesions on Initial Diffusion Weighted Imaging - Case Report and Clinical Implications

An 86-year-old lady presented after waking up with left sided paresis and neglect. Right hemispheral stroke was suspected, but initial MRI with Diffusion Weighted Imaging (DWI) was negative and there was no large vessel occlusion. We accordingly withheld intravenous thrombolysis. She did not improve clinically and follow-up MRI after three days showed a marked lesion compatible with acute ischemic stroke in the right middle cerebral artery territory. This case shows that even with a disabling stroke in the anterior circulation initial DWI may be negative. Former studies established that thrombolysis can be safe in these cases when there is no doubt about the clinical diagnosis of acute ischemic stroke

Evaluation of an Intubation Readiness Score to Assess Neonatal Sedation before Intubation

Background: Premedication for neonatal intubation facilitates the procedure and reduces stress and physiological disturbances. However, no validated scoring system to assess the effect of premedication prior to intubation is available. Objective: To evaluate the usefulness of an Intubation Readiness Score (IRS) to assess the effect of premedication prior to intubation in newborn infants. Methods: Two-center prospective study in neonates who needed endotracheal intubation. Intubation was performed using a standardized procedure with propofol 1-2 mg/kg as premedication. The level of sedation was assessed with the IRS by evaluating the motor response to a firm stimulus (1 = spontaneous movement; 2 = movement on slight touch; 3 = movement on firm stimulus; 4 = no movement). Intubation was proceeded if an adequate effect, defined as an IRS of 3 or 4, was reached. IRS was compared to the quality of intubation measured with the Viby-Mogensen intubation score. Results: A total of 115 patients, with a median gestational age of 27.7 weeks (interquartile range 5.3) and a median birth weight of 1,005 g (interquartile range 940), were included. An adequate IRS was achieved in 105 patients, 89 (85%) of whom also had a good Viby-Mogensen intubation score and 16 (15%) had an inadequate Viby-Mogensen intubation score. The positive predictive value of the IRS was 85%. Conclusions: Preintubation sedation assessment using the IRS can adequately predict optimal conditions during intubation in the majority of neonates. We suggest using the IRS in routine clinical care. Further research combining the IRS with other parameters could further improve the predictability of adequate sedation during intubation

Quantifying bladder outflow obstruction in men:A comparison of four approximation methods exploiting large data samples

Introduction: A pressure flow study (PFS), part of the International Continence Society standard urodynamic test, is regarded gold standard for the classification and quantification of the urethral resistance (UR), expressed in the bladder outflow obstruction (BOO). For men with benign prostatic hyperplasia, the minimum urethral opening pressure (pmuo), found at the end of the passive urethral resistance relation is considered the relevant parameter describing BOO. However, in clinical practice, direct measurements of pmuo are easily confounded by terminal dribbling. For that reason, alternative methods were developed to derive pmuo, and thereby assess BOO using the maximum urine flow rate (Qmax) and the corresponding pressure (pdetQmax) instead. These methods were never directly compared against a large data set. With the increasing variety of treatments becoming available more precise grading of UR may become of relevance. The current study compares four well-known methods to approximate pmuo and examines the relation between pmuo and pdetQmax. Methods: In total, 1717 high-quality PFS of men referred with lower urinary tract symptoms between 2003 and 2020 without earlier lower urinary tract surgery were included. From these recordings, pmuo was calculated according to three one-parameter methods. In addition, a three-parameter method (3PM) was used, based on a fit through the lowest pressure flank of the pressure-flow plot. The estimated pmuo's were compared with a precisely assessed pmuo. A difference of &lt;10 cmH2O between an estimate and the actual pmuo was considered accurate. A comparison between the four approximation methods and the actual pmuo was visualized using a Bland–Altman plot. The differences between the actual and the estimated slope were assessed and dependency on pmuo was analyzed. Results: A total of 1717 studies were analyzed. In 55 (3.2%) PFS, 3PM analysis was impossible because all pressures after Qmax were higher than pdetQmax. The 3PM model was superior in predicting pmuo, with 75.9% of the approximations within a range of +10 or −10 cmH2O of the actual pmuo. Moreover, pmuo according to urethral resistance A (URA) and linearized passive urethral resistance relation (linPURR) appear equally reliable. Bladder outflow obstruction index (BOOI) was significantly less accurate when compared to all others. Bland–Altman analysis showed a tendency of BOOI to overestimate pmuo in men with higher grades of UR, while URA tended to underestimate pmuo in those cases. The slope between pmuo and pdetQmax-Qmax increased with larger pmuo, as opposed to the constant relation proposed within BOOI. Although significant differences were found, the clinical relevance of those differences is not known. Conclusion: Of the four methods to estimate pmuo and quantify BOO, 3PM was found the most accurate and BOOI the least accurate. As 3PM is not generally available and performance in lower quality PFS is unknown, linPURR is (for now) the most physiologically accurate.</p

Combined Effect of Halogenation and SiO2 Addition on the Li-Ion Conductivity of LiBH4

In this work, the combined effects of anion substitution (with Br− and I−) and SiO2 addition on the Li-ion conductivity in LiBH4 have been investigated. Hexagonal solid solutions with different compositions, h-Li(BH4)1−α(X)α (X = Br, I), were prepared by ball milling and fully characterized. The most conductive composition for each system was then mixed with different amounts of SiO2 nanoparticles. If the amount of added complex hydride fully fills the original pore volume of the added silica, in both LiBH4-LiBr/SiO2 and LiBH4-LiI/SiO2 systems, the Li-ion conductivity was further increased compared to the h-Li(BH4)1−α(X)α solid solutions alone. The use of LiBH4-LiX instead of LiBH4 in composites with SiO2 enabled the development of an optimal conductive pathway for the Li ions, since the h-Li(BH4)1−α(X)α possesses a higher conductivity than LiBH4. In fact, the Li conductivity of the silica containing h-Li(BH4)1−α(X)α is higher than the maximum reached in LiBH4-SiO2 alone. Therefore, a synergetic effect of combining halogenation and interface engineering is demonstrated in this work

Effects of LiBF4 Addition on the Lithium-Ion Conductivity of LiBH4

Complex hydrides, such as LiBH4, are a promising class of ion conductors for all-solid-state batteries, but their application is constrained by low ion mobility at room temperature. Mixing with halides or complex hydride anions, i.e., other complex hydrides, is an effective approach to improving the ionic conductivity. In the present study, we report on the reaction of LiBH4 with LiBF4, resulting in the formation of conductive composites consisting of LiBH4, LiF and lithium closo-borates. It is believed that the in-situ formation of closo-borate related species gives rise to highly conductive interfaces in the decomposed LiBH4 matrix. As a result, the ionic conductivity is improved by orders of magnitude with respect to the Li-ion conductivity of the LiBH4, up to 0.9 × 10−5 S cm−1 at 30◦C. The insights gained in this work show that the incorporation of a second compound is a versatile method to improve the ionic conductivity of complex metal hydrides, opening novel synthesis pathways not limited to conventional substituents

Ionic conductivity in complex metal hydride-based nanocomposite materials: The impact of nanostructuring and nanocomposite formation

Complex metal hydrides have recently gained interest as solid electrolytes for all-solid-state batteries due to their light weight, easy deformability, and fast ion mobility at elevated temperatures. However, increasing their low conductivity at room temperature is a prerequisite for application. In this review, two strategies to enhance room temperature conductivity in complex metal hydrides, nanostructuring and nanocomposite formation, are highlighted. First, the recent achievements in nanostructured complex metal hydride-based ion conductors and complex metal hydride/metal oxide nanocomposite ion conductors are summarized, and the trends and challenges in their preparation are discussed. Then, the reported all-solid-state batteries based on complex metal hydride nanocomposite electrolytes are highlighted. Finally, future research directions and perspectives are proposed, both for the preparation of improved metal hydride ion conductors, as well as metal hydride-based all-solid-state batteries

Improving the Cycle Life of Solid-State Batteries by Addition of Oxide Nanoparticles to a Complex Hydride Solid Electrolyte

We report that the addition of silica nanoparticles to the iodide-substituted LiBH4 (h-Li(BH4)0.8(I)0.2) improves the ion conductivity and, remarkably, the cycle life of the all-solid state batteries. The h-Li(BH4)0.8(I)0.2-SiO2 was synthesized by mechanochemical treatment and possesses a Li+ conductivity of 9.3 × 10-5 S cm-1 at RT. It has an electrochemical stability window of about 2.5 V vs Li+/Li and an improved stability against Li-metal, compared to h-Li(BH4)0.8(I)0.2, owing to the addition of oxide nanoparticles, which we ascribed to a greater mechanical stability of the solid-state electrolyte. The all-solid state battery Li|h-Li(BH4)0.8(I)0.2-SiO2|TiS2 demonstrated a good long-term cyclability, i.e., over 200 cycles at C/20 and even including a C-rate of C/5, demonstrating that the addition of oxide nanoparticles improves the cycling stability of the electrolyte

Clinical epidemiology: detrusor voiding contraction maximum power related to ageing and gender

To report clinical epidemiology of detrusor (bladder) muscle contraction maximum related to ageing in patients referred with signs and symptoms of lower urinary tract dysfunction. One thousand three hundred and eight urodynamic pressure-flow measurements were analyzed in retrospective. Standard measures of detrusor muscle voiding contraction strength were compared for gender and ranked by age (range 20–90 years). A decline in maximum detrusor contraction strength was observed when the results were ranked according to age. Detrusor muscle maximum voiding contraction was on average 30% less powerful in older women and 12% less powerful in the aged men, when compared to the younger. This is transversal data – interpreted in a longitudinal manner – and from persons referred to specialist care with (the full spectrum of) signs and symptoms of lower urinary tract dysfunction. Clinical epidemiologic evaluation of patients referred with lower urinary tract symptoms, found lower detrusor maximum contraction strength in higher-age cohorts, both for women as for men. The maximum detrusor strength difference in association with age was larger in women than in men. These findings cannot simply be generalized to an asymptomatic population

Propofol for endotracheal intubation in neonates: A dose-finding trial

Objective: To find propofol doses providing effective sedation without side effects in neonates of different gestational ages (GA) and postnatal ages (PNA). Design and setting: Prospective multicentere dose-finding study in 3 neonatal intensive care units. Patients: Neonates with a PNA <28 days requiring non-emergency endotracheal intubation. Interventions: Neonates were stratified into 8 groups based on GA and PNA. The first 5 neonates in every group received a dose of 1.0 mg/kg propofol. Based on sedative effect and side effects, the dose was increased or decreased in the next 5 patients until the optimal dose was found. Main outcome measures: The primary outcome was the optimal single propofol starting dose that provides effective sedation without side effects in each age group. Results: After inclusion of 91 patients, the study was prematurely terminated because the primary outcome was only reached in 13% of patients. Dose-finding was completed in 2 groups, but no optimal propofol dose was found. Effective sedation without side effects was achieved more often after a starting dose of 2.0 mg/kg (28%) than after 1.0 mg/kg (3%) and 1.5 mg/kg (9%). Propofol-induced hypotens

Designing Highly Conductive Sodium-Based Metal Hydride Nanocomposites: Interplay between Hydride and Oxide Properties

Sodium-based complex hydrides have recently gained interest as electrolytes for all-solid-state batteries due to their light weight and high electrochemical stability. Although their room temperature conductivities are not sufficiently high for battery application, nanocomposite formation with metal oxides has emerged as a promising approach to enhance the ionic conductivity of complex hydrides. This enhancement is generally attributed to the formation of a space charge layer at the hydride-oxide interface. However, in this study it is found that the conductivity enhancement results from interface reactions between the metal hydride and the oxide. Highly conductive NaBH4 and NaNH2/oxide nanocomposites are obtained by optimizing the interface reaction, which strongly depends on the interplay between the surface chemistry of the oxides and the reactivity of the metal hydrides. Notably, for NaBH4, the best performance is obtained with Al2O3, while NaNH2/SiO2 is the most conductive NaNH2/oxide nanocomposite with conductivities of, respectively, 4.7 × 10−5 and 2.1 × 10−5 S cm−1 at 80 °C. Detailed structural characterization reveals that this disparity originates from the formation of different tertiary interfacial compounds, and is not only a space charge effect. These results provide useful insights for the preparation of highly conductive nanocomposite electrolytes by optimizing interface interactions