[Synthesis, biodegradation and waste disposal of polylactic acid plastics: a review].

With the escalation of plastic bans and restrictions, bio-based plastics, represented by polylactic acid (PLA), have become a major alternative to traditional plastics in the current market and are unanimously regarded as having potential for development. However, there are still several misconceptions about bio-based plastics, whose complete degradation requires specific composting conditions. Bio-based plastics might be slow to degrade when it is released into the natural environment. They might also be harmful to humans, biodiversity and ecosystem function as traditional petroleum-based plastics do. In recent years, with the increasing production capacity and market size of PLA plastics in China, there is an urgent need to investigate and further strengthen the management of the life cycle of PLA and other bio-based plastics. In particular, the in-situ biodegradability and recycling of hard-to-recycle bio-based plastics in the ecological environment should be focused. This review introduces the characteristics, synthesis and commercialization of PLA plastics, summarizes the current research progress of microbial and enzymatic degradation of PLA plastics, and discusses their biodegradation mechanisms. Moreover, two bio-disposal methods against PLA plastic waste, including microbial in-situ treatment and enzymatic closed-loop recycling, are proposed. At last, the prospects and trends for the development of PLA plastics are presented.

A biosensor based on oriented immobilization of an engineered l-glutamate oxidase on a screen-printed microchip for detection of l-glutamate in fermentation processes.

This paper describes an amperometric biosensor utilizing an engineered l-glutamate oxidase for glutamate monitoring in microbial fermentation processes. We designed a general immobilization strategy that utilized a chitin-binding domain (ChBD-tag) as a biotether to further immobilize l-glutamate oxidase (GLOX) in an oriented manner on a screen-printed Prussian blue nanocube microchip (PB/SPC) with the biopolymer chitosan. The improved l-glutamate biosensor exhibited an enhanced sensitivity of 53.4 µA L mmol-1 cm-2 and a linear range from 25 µmol/L to 300 µmol/L with a detection limit of 9 µmol/L, and retained 95 % of its initial activity after two weeks of usage. In addition, the as-prepared biosensor was applied for real-time monitoring of food ingredient l-glutamate concentration during the fermentation process, which was in good agreement with that of high-performance liquid chromatography (HPLC). Above all, the l-glutamate biosensor prepared by this method had high analytical performance, and could fully realize real-time and high-efficiency monitoring in glutamate fermentation.

Associated factors and abnormal dorsal raphe nucleus connectivity patterns of freezing of gait in Parkinson's disease.

BACKGROUND: Freezing of gait (FOG) is a common, disabling symptom of Parkinson's disease (PD), and its exact pathophysiological mechanism is still poorly understood. The control of gait is a complex process that may be influenced by emotions modulated by serotonergic networks. Therefore, this study aimed to determine factors associated with FOG in PD patients and to evaluate the importance of the dorsal raphe nucleus (DRN; central node in the serotoninergic system) in FOG pathophysiology. METHODS: We combined cross-sectional survey data from 453 PD patients. According to the Freezing of Gait Questionnaire (FOGQ), patients were divided into two groups: the "PD with frozen gait (PD-FOG)" and "PD without frozen gait (PD-nFOG)" groups. Demographic characteristics, clinical features, and motor and nonmotor symptoms (NMS) assessments of PD patients were recorded. Univariate statistical analysis was performed between the two groups, and then regression analysis was performed on related factors. We also acquired resting-state functional MRI (rs-fMRI) data from 20 PD-FOG, 21 PD-nFOG, and 22 healthy controls (HCs) who were randomly chosen. We defined seeds in the DRN to evaluate functional connectivity (FC) patterns. RESULTS: The overall frequency of FOG was 11.9% patients in the PD-FOG group were older, had a longer disease duration, had a higher levodopa equivalent daily dose, had more severe motor symptoms and worse quality of life, had a higher proportion of dyskinesia, wearing-off and postural instability/gait difficulty (PIGD) clinical phenotype, and experienced more depression and impaired sleep function than those in the PD-nFOG group. Logistic regression analysis showed that H&Ystage ≥ 3, UPDRS-III scores, PIGD clinical phenotype and excessive daytime sleepiness were associated with FOG. In addition, there was significantly lower FC between the DRN and some cortical structures, including the supplementary motor area (SMA), left superior frontal gyrus (SFG), and left median cingulated cortex (MCC) in PD-FOG patients than HCs and PD-nFOG patients. CONCLUSIONS: These results demonstrate that the severity of PD and PIGD clinical phenotype are associated factors for freezing and that DRN dysfunction may play a key role in PD-related NMS and FOG. An abnormal cortical and brainstem networks may contribute to the mechanisms underlying FOG.

Cognitive impairment in children with benign childhood epilepsy with centrotemporal spikes and attention deficit hyperactivity disorder: a prospective study. / ä¼´ä¸­å¤®é¢žåŒºæ£˜æ³¢çš„å„¿ç«¥è‰¯æ€§ç™«ç—«å ±æ‚£æ³¨æ„ç¼ºé™·å¤šåŠ¨éšœç¢æ‚£å„¿è®¤çŸ¥åŠŸèƒ½æŸå®³çš„å‰çž»æ€§ç ”ç©¶.

OBJECTIVES: To study the difference in cognitive impairment between the children with benign childhood epilepsy with centrotemporal spikes (BECT) and attention deficit hyperactivity disorder (ADHD) and those with BECT or ADHD alone. METHODS: A prospective study was performed on 80 children with BECT and ADHD, 91 children with BECT, and 70 children with ADHD , who were diagnosed with the diseases for the first time. Seventy children of the same age who underwent physical examination were enrolled as the healthy control group. Event-related potential P300, Wechsler Intelligence Scale for Children, and integrated visual and auditory continuous performance test were used to measure and compare each index between groups. RESULTS: Compared with the healthy control group, the BECT+ADHD group, the BECT group, and the ADHD group had a significantly prolonged P300 latency, a significant reduction in the amplitude of P300, and significant reductions in the scores of verbal comprehension index (VCI), perceptual reasoning index (PRI), working memory index (WMI), processing speed index (PSI), full scale intelligence quotient (FSIQ), auditory response control quotient (ARCQ), visual response control quotient, full response control quotient (FRCQ), auditory attention quotient (AAQ), visual attention quotient, and full attention quotient (P<0.05). Compared with the BECT group, the BECT+ADHD group had a significantly prolonged P300 latency, a significant reduction in the amplitude of P300, and significant reductions in the scores of VCI, PRI, WMI, PSI, FSIQ, and FRCQ (P<0.05). Compared with the ADHD group, the BECT+ADHD group had a significantly prolonged P300 latency, a significant reduction in the amplitude of P300, and significant reductions in the scores of VCI, PRI, FSIQ, ARCQ, FRCQ, and AAQ (P<0.05). CONCLUSIONS: Compared with the children with BECT or ADHD alone, the children with both BECT and ADHD have basically the same fields of cognitive impairment but a higher degree of cognitive impairment in some fields.

Role of cellular prion protein in splenic CD4+ T cell differentiation in cerebral ischaemic/reperfusion.

OBJECTIVE: Cellular prion protein (PrPC ), the primary form of prion diseases pathogen, has received increasing attention for its protective effect against ischaemic stroke. Little is known about its role in peripheral immune responses after cerebral ischaemia/reperfusion (I/R) injury. This study is to detect the variation of splenic CD4+ T lymphocytes differentiation and the concentration of inflammatory cytokines after murine cerebral I/R injury in the context of PRNP expression as well as its influence on the ischaemic neuronal apoptosis. METHODS: We established the cerebral ischaemic murine model of different PRNP genotypes. We detected the percentage of splenic CD4+ PrPC+ T cells of PRNP wild-type mice and the ratio of splenic Th1/2/17 lymphocytes of mice of different PRNP expression. The relevant inflammatory cytokines were then measured. Oxygen glucose deprivation/reperfusion (OGD/R) HT22 mouse hippocampal neurons were co-cultured with the T-cell-conditioned medium harvested from the spleen of modelled mice and then the neuronal apoptosis was detected. RESULTS: CD4+ PrPC+ T lymphocytes in wild-type mice elevated after MCAO/R. PRNP expression deficiency led to an elevation of Th1/17 phenotypes and the promotion of pro-inflammatory cytokines, while PRNP overexpression led to the elevation of Th2 phenotype and upregulation of anti-inflammatory cytokines. In addition, PrPC -overexpressed CD4+ T cells weakened the apoptosis of OGD/R HT-22 murine hippocampal neurons caused by MCAO/R CD4+ T-cell-conditioned medium, while PrPC deficiency enhanced apoptosis. INTERPRETATION: PrPC works as a neuron protector in the CNS when I/R injury occurs and affects the peripheral immune responses and defends against stroke-induced neuronal apoptosis.

The Role of NLRP3 Inflammasome in Cerebrovascular Diseases Pathology and Possible Therapeutic Targets.

Cerebrovascular diseases are pathological conditions involving impaired blood flow in the brain, primarily including ischaemic stroke, intracranial haemorrhage, and subarachnoid haemorrhage. The nucleotide-binding and oligomerisation (NOD) domain-like receptor (NLR) family pyrin domain (PYD)-containing 3 (NLRP3) inflammasome is a protein complex and a vital component of the immune system. Emerging evidence has indicated that the NLRP3 inflammasome plays an important role in cerebrovascular diseases. The function of the NLRP3 inflammasome in the pathogenesis of cerebrovascular diseases remains an interesting field of research. In this review, we first summarised the pathological mechanism of cerebrovascular diseases and the pathological mechanism of the NLRP3 inflammasome in aggravating atherosclerosis and cerebrovascular diseases. Second, we outlined signalling pathways through which the NLRP3 inflammasome participates in aggravating or mitigating cerebrovascular diseases. Reactive oxygen species (ROS)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), ROS/thioredoxin-interacting protein (TXNIP) and purinergic receptor-7 (P2X7R) signalling pathways can activate the NLRP3 inflammasome; activation of the NLRP3 inflammasome can aggravate cerebrovascular diseases by mediating apoptosis and pyroptosis. Autophagy/mitochondrial autophagy, nuclear factor E2-related factor-2 (Nrf2), interferon (IFN)-ß, sirtuin (SIRT), and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) reportedly alleviate cerebrovascular diseases by inhibiting NLRP3 inflammasome activation. Finally, we explored specific inhibitors of the NLRP3 inflammasome based on the two-step activation of the NLRP3 inflammasome, which can be developed as new drugs to treat cerebrovascular diseases.

Assessing the Effects of Vitamin D on Neural Network Function in Patients With Parkinson's Disease by Measuring the Fraction Amplitude of Low-Frequency Fluctuation.

Background: Recently, many studies have shown that low vitamin D (VD) levels may be related to an increased risk of Parkinson's disease (PD), but the underlying mechanisms remain unclear. Objective: To explore the relationship between PD and VD levels, as well as to analyze the effects of VD on spontaneous brain activity and explore the possible mechanism of its involvement in PD risk. Methods: In a cross-sectional study, we quantified the difference in VD levels between 330 PD patients and 209 healthy controls (HC) to explore the correlation between VD and PD risk. We also acquired resting-state Functional Magnetic Resonance Imaging (rs-fMRI) data from 46 PD patients and 21 HC. The PD patients were divided into three groups according to 25(OH)D levels: PD patients with VD deficiency (PD + VDD), PD patients with VD insufficiency (PD + VDI), and PD patients with normal VD (PD + NVD). The effect of VD status on spontaneous neuronal activity in the whole brain was analyzed by measuring the fraction amplitude of low-frequency fluctuation (fALFF). Results: Compared with HC, the PD patients had lower serum 25(OH)D levels (23.60 ± 7.27 vs. 25.60 ± 5.78, P < 0.001). The 25(OH)D level may have a potential dose-dependent effect on the risk of PD (P trend = 0.007). A high risk of PD was associated with VD deficiency [25(OH)D < 20 ng/mL, OR = 2.319], and the lowest quartile of 25(OH)D concentration was associated with a high risk of PD (OR = 1.941). In the rs-fMRI study, PD + VDD patients had wider brain regions with altered fALFF than other PD groups when compared with the corresponding HC groups. Both PD + VDD and PD + VDI showed higher fALFF in the cuneus, left precuneus, calcarine cortex and right lingual, as well as lower fALFF in the left middle temporal gyrus. PD + VDD patients also showed higher fALFF in the left superior, middle and inferior frontal gyri, as well as the left precentral gyrus than HC. Among PD patients, there was only a statistically significant difference in fALFF between the PD + VDD and PD + NVD groups. Compared with the PD + NVD group, PD + VDD patients exhibited higher fALFF in the left precentral and left postcentral gyrus, as well as the left inferior parietal lobule. Conclusion: These results demonstrate that PD patients had lower serum VD levels than HC, and VD may have a potential dose-dependent effect on PD risk. Lower serum VD levels can affect the spontaneous neuronal activity of default-mode network (DMN) and visual pathway neurons in PD patients, providing a possible mechanism for its effect on PD risk.

MicroRNA-409-3p Targeting at ATXN3 Reduces the Apoptosis of Dopamine Neurons Based on the Profile of miRNAs in the Cerebrospinal Fluid of Early Parkinson's Disease.

Precise recognition of early Parkinson's disease (PD) has always been a challenging task requiring more feasible biomarkers to be integrated to improve diagnostic accuracy. MicroRNAs (miRNAs) of cerebrospinal fluid (CSF) are believed to be potential and promising candidate biomarkers for PD. However, the role of altered miRNAs of CSF play in PD is unclear. Here, we recruited patients with early stages of PD and controls to analyze the expression of miRNA in CSF by the Next Generation Sequencing (NGS). Furthermore, we tested the levels of these miRNA in SH-SY5Y cells treated with MPP+ using real-time quantitative PCR. We found 21 miRNAs were upregulated in CSF of early PD patients and miR-409-3p, one of the identified 21 miRNAs, was further confirmed in SH-SY5Y cells treated with MPP+. Also, more cells survived in the overexpression of the miR-409-3p group when SH-SY5Y cells and mice were treated with MPP+ and MPTP, respectively. Mechanistically, we demonstrated the binding of miR-409-3p and 3'UTR of ATXN3 through a dual luciferase reporter gene assay. Moreover, miR-409-3p mimic reduced the aggregation of polyglutamine-expanded mutant of ATXN3 and apoptosis. Our results provide experimental evidence for miR-409-3p in CSF as a diagnostic marker of PD.

The relationships of vitamin D, vitamin D receptor gene polymorphisms, and vitamin D supplementation with Parkinson's disease.

In recent years, many studies have investigated the correlations between Parkinson's disease (PD) and vitamin D status, but the conclusion remains elusive. The present review focuses on the associations between PD and serum vitamin D levels by reviewing studies on the associations of PD with serum vitamin D levels and vitamin D receptor (VDR) gene polymorphisms from PubMed, Web of Science, Cochrane Library, and Embase databases. We found that PD patients have lower vitamin D levels than healthy controls and that the vitamin D concentrations are negatively correlated with PD risk and severity. Furthermore, higher vitamin D concentrations are linked to better cognitive function and mood in PD patients. Findings on the relationship between VDR gene polymorphisms and the risk of PD are inconsistent, but the FokI (C/T) polymorphism is significantly linked with PD. The occurrence of FokI (C/T) gene polymorphism may influence the risk, severity, and cognitive ability of PD patients, while also possibly influencing the effect of Vitamin D3 supplementation in PD patients. In view of the neuroprotective effects of vitamin D and the close association between vitamin D and dopaminergic neurotransmission, interventional prospective studies on vitamin D supplementation in PD patients should be conducted in the future.

Intermittent alien hand syndrome caused by Marchiafava-Bignami disease: A case report.

RATIONALE: Alien Hand syndrome (AHS) is characterized in most patients by seemingly purposeful, involuntary movements of the extremities. It is not well known among physicians on account of its diverse clinical manifestations. PATIENT CONCERNS: We present a 57-year-old Chinese man who could not stop or turn himself around as he involuntarily and uncontrollably walked forward, which had happened frequently in the month prior to treatment. He had been a heavy drinker for thirty years before the onset of the disease, with an alcohol intake of 600 to 800 ml/day. DIAGNOSES: History of alcohol intake and the brain magnetic resonance imaging findings indicated a diagnosis of Marchiafava-Bignami disease. The patient was additionally diagnosed with Alien Hand Syndrome according to his clinical symptoms. INTERVENTIONS: The patient was treated with high doses of vitamin B for 1 month. OUTCOMES: The patient's abnormal behaviors never appeared during the treatment, and no instance of recurrence was observed during the 6 months of follow-up. LESSONS: The clinical manifestation of AHS is non-specific. Only by considering its diverse manifestation can doctors better understand the disease and achieve early intervention.