Use of N-Methylmorpholine N-oxide (NMMO) pretreatment to enhance the bioconversion of lignocellulosic residues to methane.

Lignocellulosic residues (LRs) are one of the most abundant wastes produced worldwide. Nevertheless, unlocking the full energy potential from LRs for biofuel production is limited by their complex structure. This study investigated the effect of N-methylmorpholine N-oxide (NMMO) pretreatment on almond shell (AS), spent coffee grounds (SCG), and hazelnut skin (HS) to improve their bioconversion to methane. The pretreatment was performed using a 73% NMMO solution heated at 120 °C for 1, 3, and 5 h. The baseline methane productions achieved from raw AS, SCG, and HS were 54.7 (± 5.3), 337.4 (± 16.5), and 265.4 (± 10.4) mL CH4/g VS, respectively. The NMMO pretreatment enhanced the methane potential of AS up to 58%, although no changes in chemical composition and external surface were observed after pretreatment. Opposite to this, pretreated SCG showed increased porosity (up to 63%) and a higher sugar percentage (up to 27%) after pretreatment despite failing to increase methane production. All pretreatment conditions were effective on HS, achieving the highest methane production of 400.4 (± 9.5) mL CH4/g VS after 5 h pretreatment. The enhanced methane production was due to the increased sugar percentage (up to 112%), lignin removal (up to 29%), and loss of inhibitory compounds during the pretreatment. An energy assessment revealed that the NMMO pretreatment is an attractive technology to be implemented on an industrial scale for energy recovery from HS residues. Supplementary Information: The online version contains supplementary material available at 10.1007/s13399-022-03173-x.

Fed-batch anaerobic digestion of raw and pretreated hazelnut skin over long-term operation.

This study provided important insights on the anaerobic digestion (AD) of hazelnut skin (HS) by operating a fed-batch AD reactor over 240 days and focusing on several factors impacting the process in the long term. An efficient reactor configuration was proposed to increase the substrate load while reducing the solid retention time during the fed-batch AD of HS. Raw HS produced maximally 19.29 mL CH4/g VSadd/d. Polyphenols accumulated in the reactor and the use of NaOH to adjust the pH likely inhibited AD. Maceration and methanol-organosolv pretreatments were, thus, used to remove polyphenols from HS (i.e. 82 and 97%, respectively) and improve HS biodegradation. Additionally, organosolv pretreatment removed 9% of the lignin. The organosolv-pretreated HS showed an increment in methane potential of 21%, while macerated HS produced less methane than the raw substrate, probably due to the loss of non-structural sugars during maceration.

Periventricular white matter hyperintensity burden and cognitive impairment in early Parkinson's disease.

BACKGROUND AND PURPOSE: This study quantified the total brain and periventricular white matter hyperintensity (WMH) burdens in patients with early Parkinson's disease (PD) and explored their associations with cardiovascular risk factors and cognitive performance. METHODS: A total of 175 non-demented patients with early PD who had undergone baseline brain magnetic resonance imaging were included. Comprehensive neurocognitive testing was conducted to identify PD with mild cognitive impairment (PD-MCI) and to evaluate performances in individual cognitive domains. Cardiovascular risk was expressed as a modified Framingham 10-year cardiovascular risk score (mFRS). RESULTS: A total of 53.7% of this early PD cohort fulfilled the diagnostic criteria for PD-MCI. An increase in mFRS was significantly associated with increases in the total brain WMH (P = 0.015) and periventricular WMH (P = 0.040) burden, independent of age and gender. The periventricular WMH burden was significantly associated with PD-MCI (P = 0.046) in early PD, independent of cardiovascular risk factors. Patients in the 5th quintile of periventricular WMH burden were 8.6 times more likely to have PD-MCI compared with patients in the 1st quintile of periventricular WMH burden (P = 0.004). However, total brain WMH burden was not associated with PD-MCI (P = 0.158). In individual cognitive domains, heavier periventricular WMH burden was associated with worse executive function and visuospatial function independent of cardiovascular risk factors. CONCLUSION: Periventricular WMHs are a useful imaging biomarker for cognitive impairment in early PD. Cardiovascular risk factors, although associated with periventricular WMHs, were unable to fully explain the association between periventricular WMHs and cognitive impairment in early PD.

No association of DNM3 with age of onset in Asian Parkinson's disease.

BACKGROUND AND PURPOSE: Genetic variability in DNM3 has been shown to modify age of onset of Parkinson's disease (PD) among LRRK2 Gly2019Ser carriers in North African Arab-Berber populations. In Asian populations, the Gly2019Ser mutation is rare or absent but two other LRRK2 variants, Gly2385Arg and Arg1628PPro, increase PD risk. We aimed to determine whether the DNM3 locus was associated with age of PD onset in both carriers and non-carriers of LRRK2 risk variants in Asians. METHODS: We analyzed the association of DNM3 rs2421947 genotypes with age of PD onset in 3645 Chinese samples, of which 369 carried at least one of two Asian LRRK2 risk variants. RESULTS: DNM3 rs2421947 genotypes were not associated with age of PD onset in Chinese samples. We observed no heterogeneity in the effect of rs2421947 between the Asian LRRK2 risk variant carriers and non-carriers. CONCLUSIONS: DNM3 rs2421947 was not associated with age of PD onset in LRRK2 risk variant carriers and non-carriers in Chinese samples. Further studies in other Asian populations will be of interest.

Non-motor symptoms in early Parkinson's disease with different motor subtypes and their associations with quality of life.

BACKGROUND AND PURPOSE: The aim of this study was to examine non-motor symptoms in different Parkinson's disease (PD) motor subtypes and their associations with quality of life (QoL). METHODS: A total of 132 patients with early PD with comprehensive motor examinations and non-motor symptom assessments were included. Motor subtypes were classified based on Stebbins' method. Non-motor symptoms were assessed by the Non-Motor Symptom Scale (NMSS) and validated by more comprehensive instruments, including the Pittsburgh Sleep Quality Index (PSQI) and Fatigue Severity Scale (FSS). QoL was measured by the Parkinson's Disease Questionnaire-8. RESULTS: We identified 66 patients (50%) with tremor-dominant (TD) subtype, 47 (35.6%) with postural instability and gait disorder (PIGD) subtype and 19 (14.4%) with Intermediate subtype. By comparing NMSS scores, patients with the PIGD subtype had more severe sleep impairment and fatigue (domain 2 score: 5.64 vs. 2.52, P < 0.001), urinary symptoms (domain 7 score: 6.96 vs. 3.48, P = 0.005) and overall more severe non-motor symptoms (NMSS total score: 25.89 vs. 17.27, P = 0.031), compared with patients with the TD subtype. Validation using the PSQI and FSS again suggested that patients with the PIGD subtype had independently and significantly more severe sleep impairment (PSQI score: 5.57 vs. 4.29, P = 0.020) and fatigue (FSS score: 34.81 vs. 25.85, P = 0.003) compared with patients with the TD subtype. Several non-motor symptoms had significant associations with QoL, among which sleep impairment and fatigue (P < 0.0001, partial r2 = 0.273) explained the largest proportion of QoL variability in patients with PD. CONCLUSIONS: Patients with the PIGD subtype had more severe sleep impairment, fatigue and urinary disturbance compared with patients with the TD subtype. Sleep impairment and fatigue were the most important factors affecting QoL independent of motor subtypes. Prompt identification and treatment of these non-motor symptoms may improve patients' QoL.

Mood and neural correlates of excessive daytime sleepiness in Parkinson's disease.

For patients with Parkinson's disease (PD), excessive daytime sleepiness (PD-EDS) is a debilitating non-motor symptom and may be affected by mood symptoms, especially depression and anxiety. Few neuroimaging works have attempted to identify the neural features of PD-EDS, but various findings were reported. The purpose of this study was to systematically review the literature on mood and neuroimaging correlates of PD-EDS. A MEDLINE, PubMed, EMBASE, and PsycInfo search for peer-reviewed original research articles on depression, anxiety, and neuroimaging in PD-EDS identified 26 studies on depression, nine on anxiety, and eight on neuroimaging. Half of the studies reported greater depression in PD-EDS-positive patients compared with PD-EDS-negative patients. There was a significantly positive correlation between depression and PD-EDS. Limited studies on anxiety in PD-EDS suggested a weak correlation between anxiety and EDS. For depression and anxiety, the effect sizes were medium when EDS was subjectively measured, but became small when EDS was objective measured. Current neuroimaging studies generally suggested diminished neural structural and functional features (eg, brain volume, white matter integrity as indicated by fractional anisotropy, and cerebral metabolism) in patients with PD-EDS. Future studies should apply objective and subjective measures of mood symptoms and EDS and improve the neuroimaging methodology via using multimodal techniques and whole-brain analysis to provide new clues on the mood and neural correlates of PD-EDS.

[Antagonism of lovastatin on oxidative stress and apoptosis in primary rat hippocampal neurons induced by ß-amyloid peptide].

Objective: To investigate the effect of lovastatin on oxidative stress and apoptosis in neurons induced by ß-amyloid peptide (Aß). Methods: Primary culture of rat hippocampal neuron was treated with Aß oligomers alone or combined with lovastatin. The levels of OH(-), H(2)O(2), O(2)·(-), malondialdehyde, superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities were measured by biochemical methods and protein expression of caspase-3 and bcl-2 was detected by Western blot. Results: As compared with the control group, treatment of 0.5 µmol/L Aß oligomers for 48 h led to significant increase of OH(-), H(2)O(2), O(2)·(-) and malondialdehyde content, inhibition of SOD and GSH-PX activities, enhanced caspase-3 expression and decreased bcl-2 expression. Interestingly, these neurotoxic modifications on the levels of OH(-), H(2)O(2), O(2)·(-) and malondialdehyde content, SOD and GSH-PX activities, and the protein expression of cleaved caspase-3 and bcl-2 were significantly attenuated when the cells were pretreated with 0.1 µmol/L lovastatin for 24 h before exposure of Aß oligomers. Conclusion: Lovastatin may play an important role in antagonizing the neurotoxicity of Aß through a mechanism likely related to the inhibition of oxidative stress.

Facile preparation of S-doped magnetite hollow spheres for highly efficient sorption of uranium(vi).

Magnetite sorbents (MS) have been widely employed for water purification; however, adsorption capacity loss frequently occurs during the formation of magnetite sorbents. In this study, we report the preparation of S-doped magnetite hollow spheres (S-doped MHS) used for the removal of UO22+ with a large adsorption capacity of 450.0 mg U per g, higher than that of pure Fe3O4. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and a vibrating sample magnetometer (VSM) were used to determine the effectiveness of the synthesis of S-doped MHS. The S-doped MHS was investigated for the adsorption of uranium(vi) from an aqueous solution. In addition, the adsorption process fits the Freundlich isotherm model and pseudo-second-order rate equation perfectly. The affinity and selectivity of S-doped MHS for uranium(vi) is significantly high. S-doped MHS can be easily separated using an external magnetic field. Moreover, S-doped MHS can be used for the adsorption of other heavy metal ions, which indicates their promising potential applications as adsorbents in aqueous solutions.

Progression of subcortical atrophy in mild Parkinson's disease and its impact on cognition.

BACKGROUND AND PURPOSE: Mild cognitive impairment (MCI) is associated with pronounced grey matter atrophy in various brain regions. However, the association between atrophy patterns and progression from no cognitive impairment (NCI) to Parkinson's disease (PD)-MCI is not clearly known. We investigated the pattern and progression of atrophy in subcortical structures and its impact on cognition in patients with mild PD. METHODS: Sixty-five patients with mild PD with baseline and longitudinal clinical and neuropsychological assessments, and structural magnetic resonance imaging scans were studied. Movement Disorder Society Task Force criteria were used to classify patients with PD into PD-NCI (n = 54) and PD-MCI (n = 11). Based on progression over time, those who remained without cognitive impairment were classified as PD-stable (n = 42) and those who converted to MCI over 18 months were classified as PD-converters (n = 12). FreeSurfer was used to measure cortical thickness and subcortical volumes at baseline and follow-up. RESULTS: Parkinson's disease-MCI showed baseline thalamus atrophy and progressive atrophy in the thalamus, caudate, presubiculum, cornu ammonis 1 and 2-3, and significant memory and executive dysfunction compared with PD-NCI. PD-converters had greater accumbens atrophy at baseline and progressive atrophy in the thalamus, caudate and accumbens with dysfunctions in memory and executive domains. CONCLUSIONS: Progression of cognitive impairment in non-demented PD is associated with a specific pattern of subcortical atrophy. Findings from this study will allow future studies to investigate in the role of subcortical structures as a biomarker for PD dementia.

Depression, anxiety, and apathy in Parkinson's disease: insights from neuroimaging studies.

Depression, anxiety and apathy are common mood disturbances in Parkinson's disease (PD) but their pathophysiology is unclear. Advanced neuroimaging has been increasingly used to unravel neural substrates linked to these disturbances. A systematic review is provided of neuroimaging findings in depression, anxiety and apathy in PD. A PubMed, MEDLINE and EMBASE search of peer-reviewed original research articles on these mood disturbances in PD identified 38 studies on depression, eight on anxiety and 14 on apathy in PD. Most of the imaging studies used either position emission tomography or single-photon emission computed tomography techniques. These studies generally suggest increased neural activity in the prefrontal regions and decreased functional connectivity between the prefrontal-limbic networks in depressed patients. Functional imaging studies revealed an inverse correlation between dopaminergic density in the caudate and putamen with the severity of anxiety in PD. There was no consistent correlation between dopaminergic density of thalamus and anxiety. Studies demonstrated both positive and inverse correlations between apathy and metabolism or activity in the striatum, amygdalar, prefrontal, temporal and parietal regions. The clinical variability of study subjects and differences in image pre-processing and analytical strategies may contribute to discrepant findings in these studies. Both nigrostriatal and extra-nigrostriatal pathways (in particular the frontal region and its connecting areas) are affected in mood disorders in PD. Identifying the relative contributions of these neural pathways in PD patients with overlapping motor and mood symptoms could provide new pathophysiological clues for the development of better therapeutic targets for affected patients.

Clinical evolution of Parkinson's disease and prognostic factors affecting motor progression: 9-year follow-up study.

BACKGROUND AND PURPOSE: There have been few long-term studies that have characterized and charted the clinical progression of Parkinson's disease (PD). This study was therefore undertaken to understand the natural clinical evolution of treated PD patients and to identify the variables that predict greater progression in these patients. METHODS: A longitudinal linear mixed model analysis of motor score progression was performed on 576 PD patients derived from the National Neuroscience Institute Movement Disorders Database. Clinical and demographic variables were taken at baseline and formed the subgroups for comparison (gender, age at diagnosis, subtype, Mini-Mental State Examination score and baseline motor score). Motor score progression was calculated at each patient follow-up time point as the difference between Unified Parkinson's Disease Rating Scale (UPDRS) motor score at baseline and follow-up scores. RESULTS: The overall annual motor score progression as measured by the change of UPDRS motor scores from baseline ranged from 0.62% to 3.67%. There are three distinct phases: improvement, stability, and steady progression. Patients returned to baseline score 2-2.5 years after diagnosis, with stability lasting to 7 years, followed by a period of steady progression. When analyzed longitudinally, male gender (P < 0.03), older age at diagnosis (P < 0.05), akinetic-rigid subtype (P < 0.04), cognitive impairment (P < 0.005) and lower baseline motor score (P < 0.04) were associated with greater progression of motor scores. CONCLUSIONS: Our results show that, when measured clinically, motor progression was non-linear and that it occurred in distinct phases, all of which were affected by baseline demographic and clinical variables such as gender, age at diagnosis, disease subtype, cognitive status and baseline motor score.

Clinico-genetic comparisons of paroxysmal kinesigenic dyskinesia patients with and without PRRT2 mutations.

BACKGROUND AND PURPOSE: Mutations in the PRRT2 gene have been identified in patients with paroxysmal kinesigenic dyskinesias (PKD); however, not many detailed clinico-genetic correlations have been performed. METHODS: To investigate PRRT2 mutations in a mixed Asian PKD population and perform clinico-genetic correlations, we recruited patients between 2002 and 2011 and administered a standardized questionnaire. RESULTS: Amongst 29 unrelated patients with PKD recruited, five PRRT2 mutations were present in 15 patients. Three mutations (c.649dupC, c.649delC, c.649C>T) were previous reported, while three were novel mutations (c.604delT; c.609_611delACC/p.Ser202Hisfs; c.697_698delAG/p.Ser233Trp fsX5). Clinico-genetic correlations revealed that a history of seizures was more common in patients with PRRT2 mutations, although this did not reach statistical significance (P= 0.08). A younger age of onset, non-Chinese, and the presence of premonitory sensations were significantly associated with PRRT2 mutations in the univariate analysis. Multivariate logistic regression analysis demonstrated that age of onset [odds ratio (OR) = 0.59, P = 0.025] and premonitory sensation (OR = 10.67, P = 0.028) were independently associated with positive PRRT2 mutation. CONCLUSIONS: PRRT2 mutations are common in patients with PKD, and a double PRRT2 mutation is reported for the first time. PRRT2 mutations are significantly associated with a younger age of onset and the presence of premonitory sensation in our population.

Association of HLA locus variant in Parkinson's disease.

A variant (rs3129882) in the genome-wide association study (GWAS)-linked variant [in the human leukocyte antigen (HLA) gene region] has been reported to associate with an increased risk of Parkinson's disease (PD) in Caucasian population. Studies among Chinese are limited. To address this, we analysed rs3129882 in a total of 1312 subjects of Chinese ethnicity from independent Asian centers comprising of 675 controls and 637 PD cases. The rs3129882 variant was associated with a decreased risk in our ethnic Chinese PD patients. Logistic regression analysis taking into consideration variables of age, gender and race showed that allele A reduced the risk of PD via a dominant model [odds ratio (OR) = 0.77, 95% confidence interval (CI) = 0.62, 0.96, p = 0.018]. As HLA is a highly polymorphic region, it is possible that ethnic-specific effect or environmental agents may modulate the effect of this GWAS-linked locus in influencing the risk of PD.

Estimating the lifetime economic burden of Parkinson's disease in Singapore.

BACKGROUND AND PURPOSE: We aimed to estimate the lifetime cost of Parkinson's disease (PD) from the societal perspective. METHODS: A convenience sample of English or Chinese-speaking patients with PD was recruited from a PD and Movement Disorders Centre in Singapore to complete a financial burden questionnaire. Sociodemographic and clinical data were retrieved from hospital databases. Markov cohort model analysis was performed (cycle length, 1-year; duration, death or reached 100 years old). Patients were assumed to progress from one Markov state to the next state or death without skipping states or regressing. All model parameters were based on published local data. RESULTS: In 195 patients with PD (median age: 68.9, male: 51.8%), the simulated lifetime cost of PD was Singapore Dollar (SGD) 60,487 (EUR purchasing power parity 56,253) per patient. Direct medical, non-medical and indirect cost accounted for 18.8%, 12.8% and 68.4% of total lifetime cost, respectively. The top three components of total lifetime cost were productivity losses (67.6%), pharmacotherapy (11.4%) and home care (8.7%). One-way sensitivity analysis and probabilistic sensitivity analyses revealed that estimates were sensitive to cost at H&Y stage 1, 2 and 2.5 and productivity losses. CONCLUSIONS: The lifetime cost of PD is evaluated for the first time. This cost is substantial and comparable to the lifetime cost of intracerebral haemorrhage in at least one study. Our study identified several priority areas for research and policy formulation: reducing productivity losses, reducing cost of pharmacotherapy, avoiding hospitalization and reducing home care cost.

Drosophila female precopulatory behavior is modulated by ecdysteroids.

The effect of ecdysteroid signaling on Drosophila female precopulatory behavior was investigated using two types of mutants with either globally reduced ecdysteroid availability or reduced expression of ecdysone receptors in fruitless neurons, known to control sexual behavior. While being courted by males, mutant females performed significantly less full ovipositor extrusion behavior to reject male copulation attempts. Ecdysteroid depleted females (ecdysoneless(1)) performed male-like courtship behaviors, including unilateral wing extension and song production with patterns very similar to male courtship song. These results support the hypothesis that ecdysteroids modulate female sexual behavior, perhaps acting as a regulator of sexual motivation, and as a component affecting the performance of sex specific behavior patterns.

Efficacy of intraperitoneal local anaesthetic techniques during laparoscopic cholecystectomy.

BACKGROUND: Pain following laparoscopic cholecystectomy (LC) is a barrier to early discharge. Some studies have demonstrated that local anaesthetic (LA) washed over the liver and gallbladder decreases postoperative pain. In many patients pain is partially of diaphragmatic origin which may not be treated effectively by topical wash. This study assesses the efficacy of LA injected to the peritoneum of the right hemidiaphragm or topical wash with a control group. METHODS: We performed a double-blind randomized sham controlled trial of 128 consecutive subjects who underwent elective LC. Patients received subcutaneous bupivacaine, a diaphragmatic injection of bupivacaine or sham, and topical wash over the liver/gallbladder with bupivacaine or sham depending upon allocation. The primary outcome was VAS pain scores on the ward. Secondary outcomes included VRS pain scores in theatre recovery, analgesic use, physiological observations, time to eating and ambulation, and successful day-case surgery. RESULTS: Pain scores were significantly lower in both LA groups versus control in theatre recovery but only in the subperitoneal diaphragm injection group when the patients returned to the ward. Subperitoneal diaphragm injection was associated with a reduced time in theatre recovery (p = 0.04). CONCLUSIONS: Intraperitoneal techniques of LA during LC decrease postoperative pain and shorten time in theatre recovery. Injection of LA to the right hemidiaphragm is associated with lower pain scores for a longer period following LC than a previously validated wash technique.

Drosophila male courtship behavior is modulated by ecdysteroids.

Temperature-dependent induction of ecdysteroid deficiency in the ecdysoneless mutant ecd(1) adult Drosophila melanogaster results in altered courtship behavior in males. Ecdysteroid deficiency brings about significantly elevated male-male courtship behavior including song production resembling that directed toward females. Supplementation with dietary 20-hydroxyecdysone reduces male-male attraction, but does not change motor activity, courtship patterns or attraction to females. These observations support the hypothesis that reduced levels of ecdysteroids increase the probability that male fruit flies will display courtship behaviors to male stimuli.

Economic burden of Parkinson's disease in Singapore.

BACKGROUND: This study was carried out to evaluate the economic burden of Parkinson's disease (PD) and factors independently associated with individual components of total cost in Singapore. METHODS: A consecutive sample of 195 patients with PD (mean age: 68.2, men: 51.8%) attending a tertiary neuroscience clinic were identified and interviewed using standardized questionnaires including a financial burden questionnaire, two Health Related Quality of Life (HRQoL) questionnaires and the Beck Depression Inventory questionnaire. RESULTS: Annual total cost of PD from a societal perspective was SGD11345 (USD10129) per patient, with direct cost accounted for 38.5% and indirect cost 61.5%. The main cost components for direct medical cost, direct non-medical cost, and indirect cost was pharmacotherapy (50.4%), home care (76.1%), and productivity loss (97.9%), respectively. In multiple linear regression analysis, higher education, younger age and longer duration of PD were associated with higher total cost. CONCLUSIONS: Parkinson's disease exerts a considerable burden on patients, health care system and society in Singapore. As productivity loss accounts for a large share of the economic burden imposed by PD, treatments and health care programmes with potential for returning patients to higher productivity are urgently needed.