Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 134
Filter
1.
Small ; : e2403461, 2024 Aug 03.
Article in English | MEDLINE | ID: mdl-39096104

ABSTRACT

Luminescent coupling (LC) is a key phenomenon in monolithic tandem solar cells. This study presents a nondestructive technique to quantitatively evaluate the LC effect, addressing a gap in the existing predictions made by optical modeling. The method involves measuring the ratio of photons emitted from the high bandgap top cell that escape through the rear, contributing additional current to the bottom cell, and to those escaping from the front side of top cell. The findings indicate that in the analyzed monolithic perovskite/silicon tandem solar cells, more than 85% of the emitted photons escaping from the perovskite top cell are used to generate additional current in the bottom cell. This process notably reduces the mismatch in the generated current between each subcell, particularly when the current is limited by the low bandgap subcell. The presented method is applicable to a variety of monolithic tandem structures, providing vital information for subcell characterization, providing vital information for predicting energy output and optimization for outdoor applications.

2.
Front Neurol ; 15: 1411182, 2024.
Article in English | MEDLINE | ID: mdl-38978814

ABSTRACT

Introduction: New diagnostic techniques are a substantial research focus in degenerative cervical myelopathy (DCM). This cross-sectional study determined the significance of cardiac-related spinal cord motion and the extent of spinal stenosis as indicators of mechanical strain on the cord. Methods: Eighty-four DCM patients underwent MRI/clinical assessments and were classified as MRI+ [T2-weighted (T2w) hyperintense lesion in MRI] or MRI- (no T2w-hyperintense lesion). Cord motion (displacement assessed by phase-contrast MRI) and spinal stenosis [adapted spinal canal occupation ratio (aSCOR)] were related to neurological (sensory/motor) and neurophysiological readouts [contact heat evoked potentials (CHEPs)] by receiver operating characteristic (ROC) analysis. Results: MRI+ patients (N = 31; 36.9%) were more impaired compared to MRI- patients (N = 53; 63.1%) based on the modified Japanese Orthopedic Association (mJOA) subscores for upper {MRI+ [median (Interquartile range)]: 4 (4-5); MRI-: 5 (5-5); p < 0.01} and lower extremity [MRI+: 6 (6-7); MRI-: 7 (6-7); p = 0.03] motor dysfunction and the monofilament score [MRI+: 21 (18-23); MRI-: 24 (22-24); p < 0.01]. Both patient groups showed similar extent of cord motion and stenosis. Only in the MRI- group displacement identified patients with pathologic assessments [trunk/lower extremity pin prick score (T/LEPP): AUC = 0.67, p = 0.03; CHEPs: AUC = 0.73, p = 0.01]. Cord motion thresholds: T/LEPP: 1.67 mm (sensitivity 84.6%, specificity 52.5%); CHEPs: 1.96 mm (sensitivity 83.3%, specificity 65.6%). The aSCOR failed to show any relation to the clinical assessments. Discussion: These findings affirm cord motion measurements as a promising additional biomarker to improve the clinical workup and to enable timely surgical treatment particularly in MRI- DCM patients. Clinical trial registration: www.clinicaltrials.gov, NCT02170155.

3.
Arch Phys Med Rehabil ; 105(4): 682-689, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37979641

ABSTRACT

OBJECTIVE: To use the ulnar compound muscle action potential (CMAP) to abductor digiti minimi (ADM) to identify the proportion of individuals with cervical spinal cord injury (SCI) who have lower motor neuron (LMN) abnormalities involving the C8-T1 spinal nerve roots, within 3-6 months, and thus may influence the response to nerve transfer surgery. DESIGN: Retrospective analysis of prospectively collected data. Data were analyzed from European Multicenter Study About SCI database. SETTING: Multi-center, academic hospitals. PARTICIPANTS: We included 79 subjects (age=41.4±17.7, range:16-75; 59 men; N=79), who were classified as cervical level injuries 2 weeks after injury and who had manual muscle strength examinations that would warrant consideration for nerve transfer (C5≥4, C8<3). INTERVENTIONS: None. MAIN OUTCOME MEASURES: The ulnar nerve CMAP amplitude to ADM was used as a proxy measure for C8-T1 spinal segment health. CMAP amplitude was stratified into very abnormal (<1.0 mV), sub-normal (1.0-5.9 mV), and normal (>6.0 mV). Analysis took place at 3 (n=148 limbs) and 6 months (n=145 limbs). RESULTS: At 3- and 6-month post-injury, 33.1% and 28.3% of limbs had very abnormal CMAP amplitudes, respectively, while in 54.1% and 51.7%, CMAPs were sub-normal. Median change in amplitude from 3 to 6 months was 0.0 mV for very abnormal and 1.0 mV for subnormal groups. A 3-month ulnar CMAP <1 mV had a positive predictive value of 0.73 (95% CI 0.69-0.76) and 0.78 (95% CI 0.75-0.80) for C8 and T1 muscle strength of 0 vs 1 or 2. CONCLUSION: A high proportion of individuals have ulnar CMAPs below the lower limit of normal 3- and 6-month post cervical SCI and may also have intercurrent LMN injury. Failure to identify individuals with LMN denervation could result in a lost opportunity to improve hand function through timely nerve transfer surgeries.


Subject(s)
Cervical Cord , Nerve Transfer , Spinal Cord Injuries , Male , Humans , Young Adult , Adult , Middle Aged , Retrospective Studies , Ulnar Nerve
4.
J Orthop Res ; 42(1): 164-171, 2024 01.
Article in English | MEDLINE | ID: mdl-37309814

ABSTRACT

Squatting is a common daily activity and fundamental exercise in resistance training and closed kinetic chain programs. The aim of this study was to investigate the effects of an experimentally induced weakness of the gluteal muscles on joint kinematics, reactions forces (JRFs), and dynamic balance performance during deep bilateral squats in healthy young adults. Ten healthy adults received sequential blocks of (1) branch of the superior gluteal nerve to the tensor fasciae latae (SGNtfl) muscle, (2) superior gluteal nerve (SGN), and (3) inferior gluteal nerve (IGN) on the dominant right leg. At the control condition and following each block, the participants were instructed to perform deep bilateral squats standing on two force plates. Hip, knee, ankle, and pelvis kinematics did not differ significantly following iatrogenic weakness of gluteal muscles. The most important finding was the significant differences in JRFs following SGN and IGN block, with the affected hip, patellofemoral, and ankle joint demonstrating lower JRFs, whereas the contralateral joints demonstrated significantly higher JRFs, especially the patellofemoral joint which demonstrated an average maximum difference of 1.43 x body weight compared with the control condition. When performing a deep bilateral leg squat under SGN and IGN block, the subjects demonstrated an increased center of pressure (CoP) range and standard deviation (SD) in mediolateral compared with the control condition. These results imply that squat performance changes significantly following weakness of gluteal muscles and should be considered when assessing and training athletes or patients with these injuries.


Subject(s)
Hip Joint , Muscle, Skeletal , Young Adult , Humans , Biomechanical Phenomena , Hip Joint/physiology , Muscle, Skeletal/physiology , Knee Joint/physiology , Buttocks/physiology , Muscle Weakness/etiology
5.
BMC Health Serv Res ; 23(1): 1393, 2023 Dec 12.
Article in English | MEDLINE | ID: mdl-38087349

ABSTRACT

BACKGROUND: Persons with spinal cord injury (SCI) living in the community often require care. The boundaries between professional home care and informal care are blurred, and it is unclear who the typical user of home care is. The objective of this study was to describe the characteristics of persons with SCI using professional home care in Switzerland, determine the frequency of home care visits, and investigate the association of sociodemographic factors, SCI-specific characteristics, secondary health conditions, and functional independence with the use of home care. METHODS: We used cross-sectional data from the 2017 community survey of the Swiss Spinal Cord Injury Cohort Study (SwiSCI). Out of 3,959 eligible individuals 1294 completed the questionnaire and were included in the analysis (response rate 33%). Using descriptive statistics, differences between home care users and non-users as well as the frequency of home care visits were investigated. The association between sociodemographic factors, SCI-specific characteristics, secondary health conditions, functional independence and the use of home care was analyzed using multivariable logistic regression. Multiple imputation was used to account for missing data. RESULTS: Of 1,294 participants, 280 (22%) used professional home care. The median weekly professional home care duration was 6 h (Q1 = 2, Q3 = 12). More home care was used in persons with lower functional independence (Odds ratio (OR) 0.30 per 10 unit decrease in the Spinal Cord Independence Measure, 95%-Confidence interval (CI) 0.24-0.37), fewer secondary health conditions (OR 0.96 per unit Spinal Cord Injury Secondary Conditions Scale, 95%-CI 0.94-0.99), tetraplegia (OR 2.77, 95%-CI 1.92-4.00), women (OR 2.42, 95%-CI 1.70-3.43), higher age (OR 1.22 per 10 years increase, 95%-CI 1.06-1.39), living alone (OR 2.48, 95%-CI 1.53-4.03), and those receiving support from an informal caregiver (OR 1.88, 95%-CI 1.27-2.77). CONCLUSIONS: This is the first study to examine the use of professional home care from the perspective of persons with SCI in Switzerland. Lower functional independence strongly predicts increased home care use. The findings showed that professional home care complements informal care and is more likely to be used by individuals with SCI who live alone, have tetraplegia, and are female.


Subject(s)
Home Care Services , Spinal Cord Injuries , Humans , Female , Child , Male , Cross-Sectional Studies , Switzerland/epidemiology , Cohort Studies , Spinal Cord Injuries/therapy , Spinal Cord Injuries/rehabilitation , Quadriplegia
6.
Article in English | MEDLINE | ID: mdl-38032554

ABSTRACT

OBJECTIVE: To describe the occurrence of pneumonia in individuals with acute spinal cord injury (SCI) and identify its key predictors. DESIGN: Multi-centric, longitudinal cohort study. SETTING: 10 specialized SCI rehabilitation units in Europe and Australia. PARTICIPANTS: Eligible were 902 men and women with acute SCI, aged 18 years or older, with cervical or thoracic lesions and not dependent on 24-hour mechanical ventilation; 503 participated in the study (N=503). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: We assessed demographics and lesion related parameters at study entry, and any pneumonia events throughout inpatient rehabilitation. Respiratory function, decubitus, and urinary tract infections were assessed at 1, 3, and 6 months post injury as well as at discharge from inpatient rehabilitation. Time to event (pneumonia) analyses were done using the Kaplan-Meier method, and potential predictors for pneumonia were analyzed with multivariable survival models. RESULTS: Five hundred three patients with SCI were included, with 70 experiencing at least 1 pneumonia event. 11 participants experienced 2 or more events during inpatient rehabilitation. Most events occurred very early after injury, with a median of 6 days. Pneumonia risk was associated with tetraplegia (hazard ratio [HR]=1.78; 95% confidence interval [CI] 1.00-3.17) and traumatic etiology (HR=3.75; 95% CI 1.30-10.8) American Spinal Injury Impairment Scale (AIS) A (HR=5.30; 95% CI 2.28-12.31), B (HR=4.38; 95% CI 1.77-10.83), or C (HR=4.09; 95% CI 1.71-9.81) lesions. For every 10 cmH2O increase in inspiratory muscle strength, pneumonia risk was reduced by 13% (HR=0.87; 95% CI 0.78-0.97). CONCLUSION: Pneumonia is a major complication after SCI with the highest incidence very early after injury. Individuals with traumatic or AIS A, B, or C tetraplegia are at highest risk for pneumonia.

7.
Front Neurol ; 14: 1217526, 2023.
Article in English | MEDLINE | ID: mdl-38020663

ABSTRACT

Introduction: Degenerative cervical myelopathy (DCM) is the most common cause of non-traumatic incomplete spinal cord injury, but its pathophysiology is poorly understood. As spinal cord compression observed in standard MRI often fails to explain a patient's status, new diagnostic techniques to assess DCM are one of the research priorities. Minor cardiac-related cranio-caudal oscillations of the cervical spinal cord are observed by phase-contrast MRI (PC-MRI) in healthy controls (HCs), while they become pathologically increased in patients suffering from degenerative cervical myelopathy. Whether transversal oscillations (i.e., anterior-posterior and right-left) also change in DCM patients is not known. Methods: We assessed spinal cord motion simultaneously in all three spatial directions (i.e., cranio-caudal, anterior-posterior, and right-left) using sagittal PC-MRI and compared physiological oscillations in 18 HCs to pathological changes in 72 DCM patients with spinal canal stenosis. The parameter of interest was the amplitude of the velocity signal (i.e., maximum positive to maximum negative peak) during the cardiac cycle. Results: Most patients suffered from mild DCM (mJOA score 16 (14-18) points), and the majority (68.1%) presented with multisegmental stenosis. The spinal canal was considerably constricted in DCM patients in all segments compared to HCs. Under physiological conditions in HCs, the cervical spinal cord oscillates in the cranio-caudal and anterior-posterior directions, while right-left motion was marginal [e.g., segment C5 amplitudes: cranio-caudal: 0.40 (0.27-0.48) cm/s; anterior-posterior: 0.18 (0.16-0.29) cm/s; right-left: 0.10 (0.08-0.13) cm/s]. Compared to HCs, DCM patients presented with considerably increased cranio-caudal oscillations due to the cardinal pathophysiologic change in non-stenotic [e.g., segment C5 amplitudes: 0.79 (0.49-1.32) cm/s] and stenotic segments [.g., segment C5 amplitudes: 0.99 (0.69-1.42) cm/s]). In contrast, right-left [e.g., segment C5 amplitudes: non-stenotic segment: 0.20 (0.13-0.32) cm/s; stenotic segment: 0.11 (0.09-0.18) cm/s] and anterior-posterior oscillations [e.g., segment C5 amplitudes: non-stenotic segment: 0.26 (0.15-0.45) cm/s; stenotic segment: 0.11 (0.09-0.18) cm/s] remained on low magnitudes comparable to HCs. Conclusion: Increased cranio-caudal oscillations of the cervical cord are the cardinal pathophysiologic change and can be quantified using PC-MRI in DCM patients. This study addresses spinal cord oscillations as a relevant biomarker reflecting dynamic mechanical cord stress in DCM patients, potentially contributing to a loss of function.

8.
ACS Energy Lett ; 8(10): 4186-4192, 2023 Oct 13.
Article in English | MEDLINE | ID: mdl-37854048

ABSTRACT

The efficiency of perovskite/silicon tandem solar cells has exceeded the previous record for III-V-based dual-junction solar cells. This shows the high potential of perovskite solar cells in multi-junction applications. Perovskite/perovskite/silicon triple-junction solar cells are now the next step to achieve efficient and low-cost multi-junction solar cells with an efficiency potential even higher than that for dual-junction solar cells. Here we present a perovskite/perovskite/silicon triple-junction solar cell with an open circuit voltage of >2.8 V, which is the record value reported for this structure so far. This is achieved through employing a gas quenching method for deposition of the top perovskite layer as well as optimization of interlayers between perovskite subcells. Moreover, for the measurement of our triple-junction solar cells, precise measurement procedures are implemented to ensure the reliability and accuracy of the reported values.

9.
Biomedicines ; 11(7)2023 Jul 07.
Article in English | MEDLINE | ID: mdl-37509569

ABSTRACT

Transcutaneous tibial nerve stimulation (TTNS) is a promising treatment for neurogenic lower urinary tract symptoms. However, the evidence is limited due to a general lack of randomised controlled trials (RCTs) and, also, inconsistency in the sham and blinding conditions. In the context of much-needed RCTs, we aimed to develop a suitable sham-control protocol for a clinical setting to maintain blinding but avoid meaningful stimulation of the tibial nerve. Three potential electrode positions (lateral malleolus/5th metatarsal/plantar calcaneus) and two electrode sizes (diameter: 2.5 cm/3.2 cm) were tested to determine which combination provided the optimal sham configuration for a TTNS approach, based on a visible motor response. Sixteen healthy volunteers underwent sensory and motor assessments for each sham configuration. Eight out of them came back for an extra TTNS visit. Sensory thresholds were present for all sham configurations, with linear regression models revealing a significant effect regarding electrode position (highest at plantar calcaneus) but not size. In addition, motor thresholds varied with the position-lowest for the 5th metatarsal. Only using this position and 3.2 cm electrodes attained a 100% response rate. Compared to TTNS, sensory and motor thresholds were generally higher for the sham configurations; meanwhile, perceived pain was only higher at the lateral malleolus. In conclusion, using the 5th metatarsal position and 3.2 cm electrodes proved to be the most suitable sham configuration. Implemented as a four-electrode setup with standardized procedures, this appears to be a suitable RCT protocol for maintaining blinding and controlling for nonspecific TTNS effects in a clinical setting.

10.
Exp Brain Res ; 241(6): 1675-1689, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37199775

ABSTRACT

Intramuscular high-frequency coherence is increased during visually guided treadmill walking as a consequence of increased supra-spinal input. The influence of walking speed on intramuscular coherence and its inter-trial reproducibility need to be established before adoption as a functional gait assessment tool in clinical settings. Here, fifteen healthy controls performed a normal and a target walking task on a treadmill at various speeds (0.3 m/s, 0.5 m/s, 0.9 m/s, and preferred) during two sessions. Intramuscular coherence was calculated between two surface EMG recordings sites of the Tibialis anterior muscle during the swing phase of walking. The results were averaged across low-frequency (5-14 Hz) and high-frequency (15-55 Hz) bands. The effect of speed, task, and time on mean coherence was assessed using three-way repeated measures ANOVA. Reliability and agreement were calculated with the intra-class correlation coefficient and Bland-Altman method, respectively. Intramuscular coherence during target walking was significantly higher than during normal walking across all walking speeds in the high-frequency band as obtained by the three-way repeated measures ANOVA. Interaction effects between task and speed were found for the low- and high-frequency bands, suggesting that task-dependent differences increase at higher walking speeds. Reliability of intramuscular coherence was moderate to excellent for most normal and target walking tasks in all frequency bands. This study confirms previous reports of increased intramuscular coherence during target walking, while providing first evidence for reproducibility and robustness of this measure as a requirement to investigate supra-spinal input.Trial registration Registry number/ClinicalTrials.gov Identifier: NCT03343132, date of registration 2017/11/17.


Subject(s)
Gait , Walking Speed , Humans , Gait/physiology , Muscle, Skeletal/physiology , Reproducibility of Results , Walking/physiology
11.
Acta Neurochir (Wien) ; 165(6): 1533-1543, 2023 06.
Article in English | MEDLINE | ID: mdl-37079108

ABSTRACT

PURPOSE: Before the era of spinal imaging, presence of a spinal canal block was tested through gross changes in cerebrospinal fluid pressure (CSFP) provoked by manual compression of the jugular veins (referred to as Queckenstedt's test; QT). Beyond these provoked gross changes, cardiac-driven CSFP peak-to-valley amplitudes (CSFPp) can be recorded during CSFP registration. This is the first study to assess whether the QT can be repurposed to derive descriptors of the CSF pulsatility curve, focusing on feasibility and repeatability. METHOD: Lumbar puncture was performed in lateral recumbent position in fourteen elderly patients (59.7±9.3 years, 6F) (NCT02170155) without stenosis of the spinal canal. CSFP was recorded during resting state and QT. A surrogate for the relative pulse pressure coefficient was computed from repeated QTs (i.e., RPPC-Q). RESULTS: Resting state mean CSFP was 12.3 mmHg (IQR 3.2) and CSFPp was 1.0 mmHg (0.5). Mean CSFP rise during QT was 12.5 mmHg (7.3). CSFPp showed an average 3-fold increase at peak QT compared to the resting state. Median RPPC-Q was 0.18 (0.04). There was no systematic error in the computed metrics between the first and second QT. CONCLUSION: This technical note describes a method to reliably derive, beyond gross CSFP increments, metrics related to cardiac-driven amplitudes during QT (i.e., RPPC-Q). A study comparing these metrics as obtained by established procedures (i.e., infusion testing) and by QT is warranted.


Subject(s)
Cerebrospinal Fluid Pressure , Spinal Puncture , Humans , Aged , Blood Pressure , Constriction, Pathologic , Pressure
12.
Neurorehabil Neural Repair ; 37(4): 171-182, 2023 04.
Article in English | MEDLINE | ID: mdl-36919616

ABSTRACT

BACKGROUND: Sufficient and timely spinal cord decompression is a critical surgical objective for neurological recovery in spinal cord injury (SCI). Residual cord compression may be associated with disturbed cerebrospinal fluid pressure (CSFP) dynamics. OBJECTIVES: This study aims to assess whether intrathecal CSFP dynamics in SCI following surgical decompression are feasible and safe, and to explore the diagnostic utility. METHODS: Prospective cohort study. Bedside lumbar CSFP dynamics and cervical MRI were obtained following surgical decompression in N = 9 with mostly cervical acute-subacute SCI and N = 2 patients with non-traumatic SCI. CSFP measurements included mean CSFP, cardiac-driven CSFP peak-to-valley amplitudes (CSFPp), Valsalva maneuver, and Queckenstedt's test (firm pressure on jugular veins, QT). From QT, proxies for cerebrospinal fluid pulsatility curve were calculated (ie, relative pulse pressure coefficient; RPPC-Q). CSFP metrics were compared to spine-healthy patients. computer tomography (CT)-myelography was done in 3/8 simultaneous to CSFP measurements. RESULTS: Mean age was 45 ± 9 years (range 17-67; 3F), SCI was complete (AIS A, N = 5) or incomplete (AIS B-D, N = 6). No adverse events related to CSFP assessments. CSFP rise during QT was induced in all patients [range 9.6-26.6 mmHg]. However, CSFPp was reduced in 3/11 (0.1-0.3 mmHg), and in 3/11 RPPC-Q was abnormal (0.01-0.05). Valsalva response was reduced in 8/11 (2.6-23.4 mmHg). CSFP dynamics corresponded to CT-myelography. CONCLUSIONS: Comprehensive bedside lumbar CSFP dynamics in SCI following decompression are safe, feasible, and can reveal distinct patterns of residual spinal cord compression. Longitudinal studies are required to define critical thresholds of impaired CSFP dynamics that may impact neurological recovery and requiring surgical revisions.


Subject(s)
Cerebrospinal Fluid Pressure , Spinal Cord Injuries , Humans , Adolescent , Young Adult , Adult , Middle Aged , Aged , Prospective Studies , Feasibility Studies , Cerebrospinal Fluid Pressure/physiology , Spinal Cord Injuries/diagnostic imaging , Spinal Cord Injuries/surgery , Spinal Cord Injuries/cerebrospinal fluid , Decompression, Surgical/adverse effects , Decompression, Surgical/methods , Spinal Cord
13.
Nat Commun ; 14(1): 723, 2023 02 09.
Article in English | MEDLINE | ID: mdl-36759606

ABSTRACT

Cervical spinal cord injury (SCI) causes extensive impairments for individuals which may include dextrous hand function. Although prior work has focused on the recovery at the person-level, the factors determining the recovery of individual muscles are poorly understood. Here, we investigate the muscle-specific recovery after cervical spinal cord injury in a retrospective analysis of 748 individuals from the European Multicenter Study about Spinal Cord Injury (NCT01571531). We show associations between corticospinal tract (CST) sparing and upper extremity recovery in SCI, which improves the prediction of hand muscle strength recovery. Our findings suggest that assessment strategies for muscle-specific motor recovery in acute spinal cord injury are improved by accounting for CST sparing, and complement person-level predictions.


Subject(s)
Cervical Cord , Spinal Cord Injuries , Humans , Pyramidal Tracts , Retrospective Studies , Muscle, Skeletal , Recovery of Function/physiology , Spinal Cord
14.
Small ; 19(19): e2206831, 2023 May.
Article in English | MEDLINE | ID: mdl-36811154

ABSTRACT

Improving electrical and optical properties is important in manufacturing high-efficiency solar cells. Previous studies focused on individual gettering and texturing methods to improve solar cell material quality and reduce reflection loss, respectively. This study presents a novel method called saw damage gettering with texturing that effectively combines both methods for multicrystalline silicon (mc-Si) wafers manufactured using the diamond wire sawing (DWS) method. Although mc-Si is not the Si material currently used in photovoltaic products, the applicability of this method using the mc-Si wafers as it contains all grain orientations is demonstrated. It utilizes saw damage sites on the wafer surfaces for gettering metal impurities during annealing. Additionally, it can crystallize amorphous silicon on wafer surfaces generated during the sawing process to allow conventional acid-based wet texturing. This texturing method and annealing for 10 min allow for the removal of metal impurities and effectively forms a textured DWS Si wafer. The results show that the open-circuit voltage (ΔVoc  = +29 mV), short-circuit current density (ΔJsc  = +2.5 mA cm-2 ), and efficiency (Δη = +2.1%) improved in the p-type passivated emitter and rear cells (p-PERC) manufactured using this novel method, as compared to those in the reference solar cells.

15.
PM R ; 15(6): 715-730, 2023 06.
Article in English | MEDLINE | ID: mdl-35648677

ABSTRACT

BACKGROUND: Early screening is important in individuals with spinal cord injury (SCI) as they are deemed high risk for cardiometabolic diseases. Few studies explored changes in cardiometabolic risk profile in the early phase of the injury. Thus it remains unclear how early the cardiometabolic status deteriorates after injury. OBJECTIVE: To determine the longitudinal changes in the cardiometabolic risk profile and examine the association between injury characteristics and cardiometabolic status in subacute SCI. SETTING: Multicenter Swiss Spinal Cord Injury Cohort. PARTICIPANTS: Adults with traumatic SCI without a history of cardiovascular disease or type 2 diabetes. MAIN OUTCOME MEASURES: Blood pressure (BP), lipid profile, fasting glucose, waist circumference (WC), weight, body mass index (BMI), and Framingham risk score (FRS) were compared across time and according to the injury characteristics. RESULTS: We analyzed the data of 258 individuals with traumatic SCI (110 tetraplegia and 148 paraplegia, 122 motor complete, and 136 incomplete). The median age was 50 years (interquartile range [IQR] 32-60), with 76.4% (n = 197) of the population being male. The median rehabilitation duration was 5.5 months (IQR 3.2-7.1). At admission to rehabilitation, fully adjusted linear regression models showed higher baseline weight (ß 0.06, 95% confidence interval [CI] 0.005 to 0.11), systolic BP (ß 0.05, 95% CI 0.008 to 0.09), diastolic BP (ß 0.05, 95% CI 0.004 to 0.10), and triglycerides (ß 0.27, 95% CI 0.13 to 0.42) in paraplegia than tetraplegia. Systolic BP, diastolic BP, high-density lipoprotein cholesterol (HDL-C) levels were higher in incomplete than complete injury. In our main analysis, we observed an increase in cholesterol and HDL-C and lipid ratio when comparing the beginning and end of rehabilitation. Individuals with paraplegia had a higher increase in BMI than individuals with tetraplegia, whereas no differences in other cardiometabolic risk factors were detected when comparing motor incomplete and complete injury. Trajectories of each participant showed that the majority of individuals with SCI decreased FRS score at follow-up compared to baseline and no significant changes in the prevalence of cardiometabolic syndrome were observed. At discharge, one third of study participants were classified as moderate to high risk of cardiovascular disease (CVD), 64% were overweight, and 39.4% had cardiometabolic syndrome. CONCLUSION: We observed a modest improvement in lipid profile and FRS during the first inpatient rehabilitation hospitalization. Injury characteristics, such as level and completeness, were not associated with changes in cardiometabolic risk factors in the subacute phase of the injury. Despite this, a significant proportion of study participants remained at risk of cardiometabolic disease at discharge, suggesting that early cardiometabolic preventive strategies may be initiated as early as during the first inpatient rehabilitation hospitalization.


Subject(s)
Cardiovascular Diseases , Diabetes Mellitus, Type 2 , Metabolic Syndrome , Spinal Cord Injuries , Adult , Humans , Male , Middle Aged , Female , Metabolic Syndrome/epidemiology , Diabetes Mellitus, Type 2/complications , Cardiovascular Diseases/etiology , Cardiovascular Diseases/complications , Switzerland/epidemiology , Spinal Cord Injuries/rehabilitation , Paraplegia/rehabilitation , Quadriplegia/rehabilitation , Lipids
16.
Opt Express ; 31(26): 42945-42960, 2023 Dec 18.
Article in English | MEDLINE | ID: mdl-38178400

ABSTRACT

We present a simulation capability for micro-scale light-emitting diodes (µLEDs) that achieves comparable accuracy to CPU-based finite-difference time-domain simulation but is more than 107 times faster. Our approach is based on the Fourier modal method (FMM)-which, as we demonstrate, is well suited to modeling thousands of incoherent sources-with extensions that allow rapid convergence for µLED structures that are challenging to model with standard approaches. The speed of our method makes the inverse design of µLEDs tractable, which we demonstrate by designing a metasurface-enhanced µLED that doubles the light extraction efficiency of an unoptimized device.

17.
Int J Mol Sci ; 23(23)2022 Nov 30.
Article in English | MEDLINE | ID: mdl-36499379

ABSTRACT

Accelerated postsynaptic remodelling and disturbance of neuromuscular transmission are common features of autoimmune neurodegenerative diseases. Homer protein isoform expression, crosslinking activity and neuromuscular subcellular localisation are studied in mouse hind limb muscles of an experimentally induced autoimmune model of Myasthenia Gravis (EAMG) and correlated to motor end plate integrity. Soleus (SOL), extensor digitorum longus (EDL) and gastrocnemius (GAS) skeletal muscles are investigated. nAChR membrane clusters were studied to monitor neuromuscular junction (NMJ) integrity. Fibre-type cross-sectional area (CSA) analysis is carried out in order to determine the extent of muscle atrophy. Our findings clearly showed that crosslinking activity of Homer long forms (Homer 1b/c and Homer2a/b) are decreased in slow-twitch and increased in fast-twitch muscle of EAMG whereas the short form of Homer that disrupts Homer crosslinking (Homer1a) is upregulated in slow-twitch muscle only. Densitometry analysis showed a 125% increase in Homer protein expression in EDL, and a 45% decrease in SOL of EAMG mice. In contrast, nAChR fluorescence pixel intensity decreased in endplates of EAMG mice, more distinct in type-I dominant SOL muscle. Morphometric CSA of EAMG vs. control (CTR) revealed a significant reduction in EDL but not in GAS and SOL. Taken together, these results indicate that postsynaptic Homer signalling is impaired in slow-twitch SOL muscle from EAMG mice and provide compelling evidence suggesting a functional coupling between Homer and nAChR, underscoring the key role of Homer in skeletal muscle neurophysiology.


Subject(s)
Myasthenia Gravis , Neuromuscular Junction , Mice , Animals , Neuromuscular Junction/metabolism , Muscle, Skeletal/metabolism , Muscular Atrophy/metabolism , Motor Endplate , Disease Models, Animal , Homer Scaffolding Proteins/metabolism
18.
Antioxidants (Basel) ; 11(9)2022 Sep 09.
Article in English | MEDLINE | ID: mdl-36139859

ABSTRACT

A hundred years have passed since vitamin E was identified as an essential micronutrient for mammals. Since then, many biological functions of vitamin E have been unraveled in both cell and animal models, including antioxidant and anti-inflammatory properties, as well as regulatory activities on cell signaling and gene expression. However, the bioavailability and physiological functions of vitamin E have been considerably shown to depend on lifestyle, genetic factors, and individual health conditions. Another important facet that has been considered less so far is the endogenous interaction with other nutrients. Accumulating evidence indicates that the interaction between vitamin E and other nutrients, especially those that are enriched by supplementation in humans, may explain at least some of the discrepancies observed in clinical trials. Meanwhile, increasing evidence suggests that the different forms of vitamin E metabolites and derivates also exhibit physiological activities, which are more potent and mediated via different pathways compared to the respective vitamin E precursors. In this review, possible molecular mechanisms between vitamin E and other nutritional factors are discussed and their potential impact on physiological and pathophysiological processes is evaluated using published co-supplementation studies.

19.
Front Neurol ; 13: 951018, 2022.
Article in English | MEDLINE | ID: mdl-36016547

ABSTRACT

Spinal canal narrowing with consecutive spinal cord compression is considered a key mechanism in degenerative cervical myelopathy (DCM). DCM is a common spine condition associated with progressive neurological disability, and timely decompressive surgery is recommended. However, the clinical and radiological diagnostic workup is often ambiguous, challenging confident proactive treatment recommendations. Cerebrospinal fluid pressure dynamics (CSFP) are altered by spinal canal narrowing. Therefore, we aim to explore the potential value of bedside CSFP assessments for qualitative and quantitative assessment of spinal canal narrowing in DCM. In this prospective case series, seven patients with DCM underwent bedside lumbar puncture with measurement of CSFP dynamics and routine CSF analysis (NCT02170155). The patients were enrolled when standard diagnostic algorithms did not permit a clear treatment decision. Measurements include baseline CSFP, cardiac-driven CSFP peak-to-trough amplitude (CSFPp), and the Queckenstedt's test (firm pressure on jugular veins) in neutral and reclined head position. From the Queckenstedt's test, proxies for craniospinal elastance (i.e., relative pulse pressure coefficient; RPPC-Q) were calculated analogously to infusion testing. CSFP metrics were deemed suspicious of canal narrowing when numbers were lower than the minimum value from a previously tested elderly spine-healthy cohort (N = 14). Mean age was 56 ± 13 years (range, 38-75; 2F); symptom severity was mostly mild to moderate (mean mJOA, 13.5 ± 2.6; range, 9-17). All the patients showed some extent of cervical stenosis in the MRI of unclear significance (5/7 following decompressive cervical spine surgery with an adjacent level or residual stenosis). Baseline CSFP was normal except for one patient (range, 4.7-17.4 mmHg). Normal values were found for CSFPp (0.4-1.3 mmHg) and the Queckenstedt's test in normal head positioning (9.-25.3 mmHg). During reclination, the Queckenstedt's test significantly decreased in one, and CSFPp in another case (>50% compared to normal position). RPPC-Q (0.07-0.19) aligned with lower values from spine-healthy (0.10-0.44). Routine CSF examinations showed mild total protein elevation (mean, 522 ± 108 mg/ml) without further evidence for the disturbed blood brain barrier. Intrathecal CSFP measurements allow discerning disturbed from normal CSFP dynamics in this population. Prospective longitudinal studies should further evaluate the diagnostic utility of CSFP assessments in DCM.

20.
Front Hum Neurosci ; 16: 927704, 2022.
Article in English | MEDLINE | ID: mdl-35992941

ABSTRACT

Individuals regaining reliable day-to-day walking function after incomplete spinal cord injury (iSCI) report persisting unsteadiness when confronted with walking challenges. However, quantifiable measures of walking capacity lack the sensitivity to reveal underlying impairments of supra-spinal locomotor control. This study investigates the relationship between intramuscular coherence and corticospinal dynamic balance control during a visually guided Target walking treadmill task. In thirteen individuals with iSCI and 24 controls, intramuscular coherence and cumulant densities were estimated from pairs of Tibialis anterior surface EMG recordings during normal treadmill walking and a Target walking task. The approximate center of mass was calculated from pelvis markers. Spearman rank correlations were performed to evaluate the relationship between intramuscular coherence, clinical parameters, and center of mass parameters. In controls, we found that the Target walking task results in increased high-frequency (21-44 Hz) intramuscular coherence, which negatively related to changes in the center of mass movement, whereas this modulation was largely reduced in individuals with iSCI. The impaired modulation of high-frequency intramuscular coherence during the Target walking task correlated with neurophysiological and functional readouts, such as motor-evoked potential amplitude and outdoor mobility score, as well as center of mass trajectory length. The Target walking effect, the difference between Target and Normal walking intramuscular coherence, was significantly higher in controls than in individuals with iSCI [F(1.0,35.0) = 13.042, p < 0.001]. Intramuscular coherence obtained during challenging walking in individuals with iSCI may provide information on corticospinal gait control. The relationships between biomechanics, clinical scores, and neurophysiology suggest that intramuscular coherence assessed during challenging tasks may be meaningful for understanding impaired supra-spinal control in individuals with iSCI.

SELECTION OF CITATIONS
SEARCH DETAIL