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One of the most interesting study areas in the renewable energy production is highly efficient water splitting that relies on the solar energy. More promising photocatalysts which can operate under irradiation from visible light are vitally required. Herein, based on the density functional theory, we demonstrated that two-dimensional SiH and β-SiTe monolayers exhibit indirect bandgap and suitable band edge locations for photocatalytic splitting of water. Using the PBE approach, we found that the bandgap values for the SiH and β-SiTe monolayer are 2.19 eV and 1.86 eV, respectively. The rectified bandgaps using the HSE06 function for SiH and β-SiTe were 2.93 eV and 2.43 eV, respectively. Surprisingly, photocatalytic property studies demonstrated that SiH and β-SiTe monolayers act as efficient photocatalysts for the production of hydrogen. Our outcomes emphasized that the highest peak of the absorption coefficient of SiH monolayer is 17.1 × 10 4 cm −1 in the UV region specifically at energy 7.90 eV. While β-SiTe monolayer has two peaks absorption of (13.5 × 10 4 and 8.1 × 10 4 ) cm −1 in the UV region at energies (7.18 and 9.22) eV. The results presented here imply that the SiH and β-SiTe could be useful in thermoelectric applications and the construction of photovoltaic cells and catalysts.

Objective This study aimed to investigate the prevalence of REM sleep behavior disorder (RBD) in patients with spontaneous intracranial hypotension (SIH) and longitudinally assess the effects of epidural blood patch (EBP) treatment on brainstem structures using a neuroimaging approach. Methods Twenty-two participants (10 SIH patients and 12 controls) underwent 3-Tesla Magnetic Resonance Imaging (MRI) scans. Midbrain and pons areas were measured on T1-weighted scans at baseline in both groups and three months after the first EBP in SIH patients to determine any MRI structural changes. The RBD Single-Questionnaire was used to screen SIH patients with symptoms suggestive of RBD for polysomnographic (PSG) recording. Results Half of the SIH patients (5/10) exhibited PSG-confirmed RBD. Baseline evaluation revealed deep brain swelling (DBS) on MRI scans in SIH-RBD patients. Following EBP treatment, significant changes in midbrain and pons morphometry were associated with complete clinical remission of RBD. Cross-sectional analysis showed larger midbrain and pons areas in SIH patients (with and without RBD) compared to controls. A midbrain area of 200 mm 2 was identified as a cut-off value distinguishing SIH patients (with and without RBD) from controls individually. Longitudinal analysis demonstrated lower midbrain areas at follow-up compared to baseline in SIH patients. Discussion The study suggests that brainstem morphometric changes may underlie reversible RBD in SIH patients. Midbrain area measurement could serve as a dynamic biomarker for SIH, particularly in the presence of RBD, offering insights for clinical practice.

BackgroundEstimation of intracranial pressure (ICP) may be helpful in the management of neurological critically ill patients. It has been shown that ultrasonography of the optic nerve sheath diameter (ONSD) is a reliable tool for non-invasive estimation of increased intracranial pressure (ICP) at hospital admission or in intensive care. Less is known about the estimation of increased ICP and usefulness of ONSD in the prehospital setting. The aim of this review was to elucidate both prevailing and novel applications of ONSD for neurologists and critical care physicians.MethodsIn this review, we discuss the technique and the novel approach of ONSD measurement, the clinical applications of ONSD in neurology and critical care patients.ResultsONSD measurement is simple, easy to learn, and has diverse applications. ONSD has utility for ICP measurement in intracranial hemorrhage and ischemic stroke, meningitis and encephalitis, and idiopathic intracranial hypertension (IIH). It is also valuable for lesser known syndromes, where an increase of ICP is postulated, such as acute mountain sickness and posterior reversible encephalopathy syndrome. ONSD changes develop in inflammatory or ischemic optic neuropathies. Some papers demonstrate the usefulness of ONSD studies in symptomatic intracranial hypotension.ConclusionsONSD is a safe and low-cost bedside tool with the potential of screening patients who need other neuroimaging and those who may need an invasive measurement of ICP.

Stress-induced hyperglycemia (SIH) is a physiological response to acute or chronic stress characterized by elevated blood glucose levels. It is prevalent in both patients with and without diabetes, particularly those with acute or critical illnesses. The development of SIH is characterized by complex interactions among catecholamines, cortisol, and inflammatory mediators such as cytokines, resulting in increased hepatic glucose production and insulin resistance. While mild to moderate SIH may provide a protective mechanism during stress, prolonged or excessive hyperglycemia can exacerbate inflammation and oxidative stress, contributing to adverse outcomes in conditions such as acute myocardial infarction, heart failure, and cerebrovascular diseases. The stress-hyperglycemia ratio (SHR), defined as the ratio of admission glucose to estimated mean glucose (derived from glycated hemoglobin [HbA1c]), has emerged as a valuable tool for quantifying stress hyperglycemia. Unlike absolute glucose levels, the SHR accounts for background hyperglycemia and provides a more accurate indicator of the relative glucose elevation associated with critical illness. Extensive research has demonstrated a U-shaped or J-shaped relationship of the SHR with disease outcomes, indicating that both low and high SHRs are associated with increased mortality and morbidity. The SHR has shown significant predictive value in cardiovascular diseases (e.g., acute coronary syndrome, heart failure), cerebrovascular diseases (e.g., acute ischemic stroke, intracerebral hemorrhage), and infectious diseases (e.g., sepsis, pneumonia). It also plays a role in other conditions, such as acute pancreatitis and certain cancers. The ease of calculating the SHR from widely available admission glucose and HbA1c tests makes it a practical and valuable prognostic marker in clinical settings. This review examines the relationship between the SHR and critical illnesses, highlighting its mechanisms and predictive value across various diseases. Graphical abstract Predictive value of SHR in cardiovascular, cerebrovascular, infectious, and other diseases.

Background and purpose Spinal cerebrospinal fluid (CSF) leaks may cause a myriad of symptoms, most common being orthostatic headache. In addition, ventral spinal CSF leaks are a possible etiology of superficial siderosis (SS), a rare condition characterized by hemosiderin deposits in the central nervous system (CNS). The classical presentation of SS involves ataxia, bilateral hearing loss, and myelopathy. Unfortunately, treatment options are scarce. This study was undertaken to evaluate whether microsurgical closure of CSF leaks can prevent further clinical deterioration or improve symptoms of SS. Methods This cohort study was conducted using data from a prospectively maintained database in two large spontaneous intracranial hypotension (SIH) referral centers in Germany and Switzerland of patients who meet the modified International Classification of Headache Disorders, 3rd edition criteria for SIH. Patients with spinal CSF leaks were screened for the presence of idiopathic infratentorial symmetric SS of the CNS. Results Twelve patients were included. The median latency between the onset of orthostatic headaches and symptoms attributed to SS was 9.5 years. After surgical closure of the underlying spinal CSF leak, symptoms attributed to SS improved in seven patients and remained stable in three. Patients who presented within 1 year after the onset of SS symptoms improved, but those who presented in 8–12 years did not improve. We could show a significant association between patients with spinal longitudinal extrathecal collections and SS. Conclusions Long‐standing untreated ventral spinal CSF leaks can lead to SS of the CNS, and microsurgical sealing of spinal CSF leaks might stop progression and improve symptoms in patients with SS in a time‐dependent manner. Long‐standing untreated ventral spinal cerebrospinal fluid (CSF) leaks can lead to superficial siderosis of the central nervous system. Microsurgical sealing of spinal CSF leaks might stop progression and improve symptoms in patients with superficial siderosis in a time‐dependent manner. Therefore, searching for spinal CSF leaks in all patients with superficial siderosis with a thorough workup is strongly recommended.

This paper investigates the photodissociation of the SiH+ molecular ion, a non-symmetric diatomic species composed of silicon and hydrogen. We provide calculated molecular data and characterize electronic states, deriving cross-sections and spectral absorption rate coefficients as functions of temperature (1000–10,000 K) and EUV and UV wavelength. The calculations are performed within a quantum–mechanical framework of bound–free radiative transitions, using ab initio electronic potentials and dipole transition functions as inputs. In addition, we present a straightforward fitting formula that enables practical interpolation of photodissociation cross-sections and spectral rate coefficients, providing a novel closed-form representation of the dataset for modeling purposes. The resulting dataset provides a consistent and accessible reference for advanced photochemical modeling in laboratory plasmas and astrophysical environments.

Retroclival subdural hematoma (rcSDH) secondary to spontaneous intracranial hypotension (SIH) is an exceedingly rare clinical entity, characterized by complex and incompletely understood pathophysiological mechanisms. A 24-year-old female presented with acute and persistent orthostatic headache, with no history of trauma or anticoagulant therapy. Neuroimaging revealed subdural hematomas (SDH) located in the retroclival, infratentorial, and right frontal regions. It was hypothesized that veinous rupture, resulting from venous traction due to decreased cerebrospinal fluid (CSF) pressure, was the underlying mechanism. Following epidural blood patch (EBP) therapy, the patient exhibited marked symptomatic improvement and radiological resolution of hematomas on follow-up imaging. RcSDH is considered an uncommon complication of SIH, potentially resulting from venous rupture in the retroclival subdural space due to reduced CSF pressure. SIH should be considered in cases of rcSDH. The treatment is typically focused on addressing the underlying etiology, with early diagnosis and timely intervention being essential for achieving favorable outcomes. In cases of severe brainstem compression, hematoma evacuation should be performed in conjunction with EBP.

To report CSF pressure (Pcsf) and its correlations in patients with SIH due to CSF-venous fistula (CVF). Following IRB approval, consecutive SIH patients undergoing myelography between 2021 and 2025 at a single center were retrospectively analyzed. Pcsf was defined as opening pressure (OP) during myelography, with patient in decubitus positioning with mild hip elevation. Low OP was defined as < 6 cm H2O; elevated OP as > 20 cm H2O. Of the 86 SIH patients analyzed, 35 (41 %) had a CVF [average age 59 ± 13; 12/35 (34 %) male; 23/35 (66 %) female]. Of the 35, OP was reported for 32 patients. The mean ± SD OP was 13.97 ± 3.91 cm H2O (range: 6–25 cm H2O). None (0 %) of the patients had low OP. 29/32 (91 %) had OP in normal range, 3/32 (9 %) had elevated OP. Pcsf was positively correlated with BMI (p = 0.045); but not correlated with age, sex, prior epidural blood patching, symptom duration, or mean arterial pressure. High variability in Pcsf values was not fully accounted for by predictors included in our model (pseudo-R2 = 0.188). An absence of low Pcsf should not be used to rule out SIH, as all our patients with SIH due to CVF had normal or elevated Pcsf. Such Pcsf readings in patients with active CSF leaks suggest that the development of CVF and post-treatment rebound headaches may be due to pre-existing intracranial hypertension. While BMI is positively correlated with Pcsf, limited explanatory power of our model suggests influence of other factors. •All our SIH patients with CSF-venous fistula (CVF) had normal or high CSF pressures (Pcsf).•Absence of low Pcsf should not be used to rule out SIH.•Development of CVF and post-treatment rebound headaches may be due to pre-existing IIH.•BMI is positively correlated with Pcsf. Age, sex, prior EBP, symptom duration, MAP not correlated.•CVF has varied presentation. Atypical symptoms like cognitive changes are more common than previously reported.

Background and objectivesThe precise site of dural leaks in patients with spontaneous intracranial hypotension (SIH) is challenging to identify. We investigated for the first time the ability of the dural displacement sign seen on 3D T2 FIESTA (Fast Imaging Employing Steady-state Acquisition) weighted MR imaging to depict epidural collections and show the leakage site in type 1 leaks in patients with SIH.Materials and methodsIn a retrospective study, 23 patients with confirmed type 1 leakage received an MR of the spine with 3D T2 FIESTA-weighted imaging and ultrafast dynamic CT myelography. The two modalities were compared in 22 patients in relation to the leakage site. In one patient, conventional CT myelography (CTM) was used at our site, but an ultrafast dynamic CT myelography was later conducted at another site and confirmed the leakage location. Two neuroradiologists performed the evaluations while blinded.ResultsDural displacement sign in the upper thoracic spine was identified in 12 of 13 patients (92%) in the upper thoracic spine, whereas it was not identified in the remaining 10 patients with leaks in the cervical, lower thoracic or lumbar regions. A Type 1 leakage in the upper thoracic region was at the exact same level as the dural displacement sign in 9 (72%) patients and in the remaining 3 the leakage level was located at one level below the dural displacement sign. In one of the 3 patients where the leakage was located at the level below the visible dural displacement sign, a dural tear at the leakage level in the form of discontinuity of the dura was identified.Conclusions3D FIESTA sequences and the dural displacement sign show the potential site of type 1 leakage in the upper thoracic spine. We find that the 3D FIESTA sequence and the dural displacement sign can be valuable when planning ultrafast dynamic CT myelography. This may reduce the investigation time and the radiation doses.

Background: Admission hyperglycemia is associated with higher morbidity and mortality in patients with traumatic brain injury (TBI). Stress-induced hyperglycemia (SIH), a form of hyperglycemia induced by the stress response, is associated with increased patient mortality following TBI. However, admission hyperglycemia occurs not only in SIH but also in patients with diabetic hyperglycemia (DH). Current information regarding whether trauma patients with SIH represent a distinct group with differential outcomes compared to those with DH remains limited. Methods: Serum glucose concentration ≥200 mg/dL upon arrival at the emergency department was defined as hyperglycemia. Presence of diabetes mellitus (DM) was determined by patient history and/or admission glycated hemoglobin (HbA1c) level ≥6.5%. In the present study, the patient cohort included those with moderate and severe TBI, as defined by an Abbreviated Injury Scale (AIS) score ≥3 points in the head, and excluded those who had additional AIS scores ≥3 points in any other region of the body. A total of 1798 adult patients with isolated moderate to severe TBI were allocated into four groups: SIH (n = 140), DH (n = 187), diabetic normoglycemia (DN, n = 186), and non-diabetic normoglycemia (NDN, n = 1285). Detailed patient information was retrieved from the Trauma Registry System at a level I trauma center between 1 January 2009, and 31 December 2015. Unpaired Student’s t- and Mann–Whitney U-tests were used to analyze normally and non-normally distributed continuous data, respectively. Categorical data were compared using the Pearson chi-square or two-sided Fisher’s exact tests. Matched patient populations were allocated in a 1:1 ratio according to propensity scores calculated by NCSS software. Logistic regression was used to evaluate the effect of SIH and DH on the adjusted mortality outcome. Results: In patients with isolated moderate to severe TBI, the presence of SIH and DH led to 9.1-fold and 2.3-fold higher odds of mortality, respectively, than patients with NDN. After adjusting for confounding factors, including sex and age, pre-existing co-morbidities, existence of different kinds of intracerebral hemorrhage, and injury severity, patients with SIH still had 6.6-fold higher odds of mortality than those with NDN; however, DH did not present significantly higher adjusted mortality odds. SIH and DH presented different effects on outcomes after TBI. The results also suggested that the pathophysiological effect associated with SIH was different from that of DH. Conclusions: This study demonstrated that patients with SIH and DH had significantly higher mortality than patients with NDN. However, the adjusted mortality was significantly higher only in the selected propensity score-matched patients with SIH and not in those with DH.