Kinetics of plasma cell-free DNA as a prospective biomarker to predict the prognosis and radiotherapy effect of esophageal cancer.

PURPOSE: The lack of reliable biomarkers for the prognosis and radiotherapy efficacy in esophageal cancer (EC) necessitates further research. The aim of our study was to investigate the predictive utility of plasma cell-free DNA (cfDNA) kinetics in patients with EC. MATERIALS AND METHODS: We retrospectively analyzed the clinical data and cfDNA levels (pre-radiotherapy [pre-RT] and post-radiotherapy [post-RT]) and the cfDNA kinetics (cfDNA ratio: post-RT cfDNA/pre-RT cfDNA) of 88 patients. We employed Kaplan-Meier curves to examine the relationship between cfDNA and overall survival (OS) as well as progression-free survival (PFS). Univariate and multivariate Cox regression analyses were executed to ascertain the independent risk factors in EC. RESULTS: The pre-RT cfDNA levels were positively correlated with clinical stage (P=0.001). The pre-RT cfDNA levels (cutoff value=16.915ng/mL), but not the post-RT cfDNA levels, were linked to a diminished OS (P<0.001) and PFS (P=0.0137). CfDNA kinetics (cutoff value=0.883) were positively associated with OS (P=0.0326) and PFS (P=0.0020). Notably, we identified independent risk factors for OS in EC treated with RT, including cfDNA ratio (high/low) (HR=0.447 [0.221-0.914] P=0.025), ECOG (0/1/2) (HR=0.501 [0.285-0.880] p=0.016), and histological type (esophagal squamous cell carcinoma [ESCC]/non-ESCC) (HR=3.973 [1.074-14.692] P=0.039). CONCLUSION: Plasma cfDNA kinetics is associated with prognosis and radiotherapy effect in EC undergoing RT, suggesting potential clinical application of a cheap and simple blood-based test.

Role of diatom-derived oxylipins in organic phosphorus recycling during coastal diatom blooms in the northern South China Sea.

Diatom-bacteria interactions and the associated bloom dynamics have not been fully understood in the coastal oceans. Here, we focus on the polyunsaturated aldehydes (PUAs) produced by diatoms in the post-bloom phase and look into their roles in microbial phosphorus (P) recycling outside of a P-limited estuary. The phytoplankton community in the bloom was dominated by PUAs-producing diatoms (Skeletonema costatum, Thalassiosira spp., and Pesudonitzschia delicates) with elevated concentrations of biogenic particulate PUAs. In addition, there were micromolar levels of particle-adsorbed PUAs hotspots with distinct compositions in and out of the bloom determined by a combining large-volume filtration and on-site derivation method. Field experiments were conducted to further assess the responses of particle-attached bacteria (PAB) to different PUAs amendments. We found no differences in the alkaline phosphatase (APase) activity and the abundance of PAB between inside and outside the bloom at a low PUAs dosage (<30 µM). However, for a high PUAs dosage (300 µM), APase activity and PAB growth were reduced significantly outside the bloom but no influences within the bloom. Our findings indicate that the hotspot-level oxylipins may play essential roles in bacterial P-remineralization in P-limited coastal areas. PAB can adapt to the high level of PUAs released by diatoms (or their resulting detritus) and potentially maintain a high rate of organic P recycling during the late stages of diatom blooms. Consequently, the interaction between oxylipin-rich diatoms and bacteria may affect phytoplankton blooms and carbon sequestration in the coastal oceans.

Microplastic pollution and regulating factors in the surface sediment of the Xuande Atolls in the South China Sea.

Microplastics are widely present in the marine environment, but their pollution and potential risk assessment in the seabed sediments have not been well addressed in remote sea areas. In this study, microplastics in 50 surface sediment samples from the Xuande Atolls at the Xisha of the South China Sea were studied. There were 20 samples with detectable microplastics of 5-20 items kg-1. They were all fibers in shapes and blue/transparent in colors with the dominant chemical component of polyester and the typical size of 0.02-3 mm. We found a large spatial variability of microplastic abundance in the surface sediment with generally low or undetectable levels in the lagoon deposits and the offshore deep-sea sediments but elevated abundances in the slope sediments of the Xuande Atolls. Correlation analyses suggested that microplastic variability in the Xisha sediment was less affected by local environmental parameters such as water depth, sediment particle size, organic carbon content, and sediment types. We also found that elevated microplastics in the seabed sediments on various sides of the Xuande Atolls could be related to the seasonal change in monsoon-driven currents. Finally, a low risk of microplastic pollution in the surface sediment of the Xisha is concluded based on the assessments of the polymer hazard index and the pollution load index. These findings provide not only a baseline understanding of microplastics but also their dynamics in the surface sediment of the remote Xisha area of the South China Sea.

Microplastic contamination in coral reef fishes and its potential risks in the remote Xisha areas of the South China Sea.

Microplastics are recognized as a newly emerging threat to marine organisms as they can be ingested and accumulated through multiple trophic levels. However, microplastic contamination and its potential risk assessment in coral reef fishes have been less addressed, particularly in remote ocean regions. In this study, microplastics in 167 samples of coral reef fish (a total of eighteen species) from the Xisha areas of the South China Sea were studied. There were fifteen species of coral reef fish contaminated by microplastics with an average occurrence rate of 29.3 %. The shape of microplastics in the fishes was mostly fibrous with small sizes (400-900 µm) and light colors (transparent and blue). The dominant types of microplastic polymers are polyamide and polyethylene terephthalate, accounting for 77 % and 11 % of microplastics in the fish body. There were generally more microplastics in the herbivorous fishes than the carnivorous ones. The highest microplastic abundance and occurrence was found in parrotfish due to its direct feeding on the microplastics-contaminated corals. In addition, there were much more microplastics in the gastrointestinal tracts than in the gills of the Xisha fishes. Microplastic abundance was found negatively correlated with the trophic level of the Xisha fishes supporting a stronger microplastic impact at lower levels of marine animals. Finally, a risk assessment using the polymer hazard index (PHI) revealed that microplastic contamination in the Xisha fishes was lower than those in the eutrophic coast. Our study provides new evidence for the widespread presence of microplastic contamination in the fishes of the remote Xisha coral reefs.

Transparent exopolymer particle dynamics along a shelf-to-sea gradient and impacts on the regional carbon cycle.

Transparent exopolymer particles (TEPs) have drawn extensive attention in recent decades due to their crucial role in the biogeochemical and ecological processes of the ocean. However, TEP distribution and fluxes are relatively less addressed in the shelf-seas, where its variability can be affected by not only biology but also complex physical dynamics. Here, we present a comprehensive study of TEP from the coast to the basin (12 sampling sites) of the northern South China Sea (NSCS). We found a large TEP variability from 0.6 to 78.6 µg Xeq. L-1 with higher levels in the coastal waters than the offshore epipelagic waters and the deep waters. In addition, the spatial distribution of TEP was significantly correlated to the cross-shelf change of temperature, salinity, and chlorophyll-a, revealing the complex physical-biogeochemical controls on TEP variability. We found the TEP dynamics nearshore largely influenced by the sedimentation and transportation of TEP-rich aggregates from the river plume. The contribution of TEP to particulate organic carbon (POC) increased gradually when approaching the shore from the sea, suggesting an elevated role of TEP in the coastal carbon cycle. Finally, a good correlation of particle-attached bacteria (PAB) with TEP but not POC revealed a preferential utilization of TEP by PAB. Thus, TEP may play an essential role in the recycling of carbon and nitrogen in the shelf-sea. These findings are crucial for understanding of the TEP dynamics under a changing environment and the associated impacts on the oceanic carbon cycle.

[Association between polymorphism of CASP and NOX3 with risk of noise-induced hearing loss].

Objective: To explore the effect of gene polymorphism on workers suffering from noise induced hearing loss (NIHL) . Methods: In May 2019, a case-control study was conducted to select noise exposed workers in five factories in Zhejiang Province from 2017 to 2018. The average hearing threshold of binaural high frequency (3, 4, 6 kHz) was >25 dB (A) as the NIHL group, and the hearing threshold of any language frequency (0.5, 1, 2 kHz) was ≤25 dB (A) as the non NIHL group, with 307 people in each group. The general demographic data, occupational history, pure tone audiometry results and oral swab mucosal samples of noise exposed workers were collected, and the DNA of oral mucosal cells was extracted. The relationship between genetic risk score (GRS) and NIHL was analyzed, single nucleotide polymorphisms (SNP) were genotyped, the relationship between genotype and NIHL was analyzed by logistic regression, and the relationship between haplotype and NIHL was analyzed by R language. Results: After adjusting for gender, age, education and working years, the risk of NIHL among workers carrying cysteine-aspartic acid protease 3 gene (CASP3) rs1049216 recessive model GG genotype, rs6948 recessive model TT genotype, NADPH oxidase 3 gene (NOX3) rs12195525 additive model GT genotype and dominant model TT+GT genotype decreased (P<0.05) , the risk of disease was higher in workers with AA genotype carrying cysteine-aspartic acid protease 7 gene (CASP7) rs12415607 additive model (P<0.05) . There was a strong linkage disequilibrium (LD) relationship between rs1049216 and rs6948 (D'>0.8) . Haplotype AT and GG composed of rs1049216-rs6948 increased the risk of NIHL (P<0.05) . The risk of NIHL increased with the increase of GRS (OR=2.69, P<0.05) . Conclusion: Genotype polymorphisms at rs1049216 and rs6948 (CASP3) , rs12195525 (NOX3) , rs12415607 (CASP7) may be associated with susceptibility to NIHL.

Dynamic contrast-enhanced magnetic resonance imaging: A novel approach to assessing treatment in locally advanced esophageal cancer patients.

AIMS: This study aims to investigate the potential application of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to predict concurrent chemoradiation (CRT) in locally advanced esophageal carcinoma. PATIENTS AND METHODS: This study involved 33 patients with locally advanced esophageal cancer and treated with CRT. The patients underwent DCE-MRI before CRT (pre) and 3 weeks after starting CRT (mid). The patients were categorized into two groups: complete response (CR) and non-complete response (non-CR) after 3 months of treatment. The quantitative parameters of DCE-MRI (Ktrans, Kep, and Ve), the changes and ratios of parameters (ΔKtrans, ΔKep, ΔVe, rΔKtrans, rΔKep, and rΔVe), and the relative ratio in the tumor area and a normal tube wall (rKtrans, rKep, and rVe) were calculated and compared between two timeframes in two groups, respectively. Moreover, the receiver operating characteristics (ROC) statistical analysis was used to assess the above parameters. RESULTS: We divided 33 patients into two groups: 22 in the CR group and 11 in the non-CR group. During the mid-CRT phase in the CR group, both Ktrans and Kep rapidly decreased, while only Kep decreased in the non-CR group. The pre-Ktrans and pre-Kep in the CR group were substantially higher compared to the non-CR group. Moreover, the rKtrans was also apparently observed as higher at pre-CRT in the CR group compared to the non-CR group. The ROC analysis demonstrated that the pre-Ktrans could be the best parameter to evaluate the treatment performance (AUC = 0.74). CONCLUSION: Pre-Ktrans could be a promising parameter to forecast how patients with locally advanced esophageal cancer will respond to CRT.

Surface modification of titanium carbide MXene monolayers (Ti2C and Ti3C2) via chalcogenide and halogenide atoms.

Inspired by the recent successful growth of Ti2C and Ti3C2 monolayers, here, we investigate the structural, electronic, and mechanical properties of functionalized Ti2C and Ti3C2 monolayers by means of density functional theory calculations. The results reveal that monolayers of Ti2C and Ti3C2 are dynamically stable metals. Phonon band dispersion calculations demonstrate that two-surface functionalization of Ti2C and Ti3C2via chalcogenides (S, Se, and Te), halides (F, Cl, Br, and I), and oxygen atoms results in dynamically stable novel functionalized monolayer materials. Electronic band dispersions and density of states calculations reveal that all functionalized monolayer structures preserve the metallic nature of both Ti2C and Ti3C2 except Ti2C-O2, which possesses the behavior of an indirect semiconductor via full-surface oxygen passivation. In addition, it is shown that although halide passivated Ti3C2 structures are still metallic, there exist multiple Dirac-like cones around the Fermi energy level, which indicates that semi-metallic behavior can be obtained upon external effects by tuning the energy of the Dirac cones. In addition, the computed linear-elastic parameters prove that functionalization is a powerful tool in tuning the mechanical properties of stiff monolayers of bare Ti2C and Ti3C2. Our study discloses that the electronic and structural properties of Ti2C and Ti3C2 MXene monolayers are suitable for surface modification, which is highly desirable for material property engineering and device integration.

[Electroclinical characteristics of epilepsy children with midline epileptiform discharges related epileptic negative myoclonus as the first symptom].

Objective: To investigate the electroclinical findings in epilepsy children with epileptic negative myoclonus (ENM) restricted to the lower limb as the first seizure type. Methods: Each retrieved electroencephalogram record performed between March 2011 and March 2018 at the Department of Pediatrics of Peking University First Hospital was searched with "midline" . There were 302 records of 175 patients with "benign" or "functional" midline spikes. A retrospective review of each patient's hospital record was performed. Thirteen patients had ENM restricted to the lower limb as the first seizure type. The clinical and electroencephalogram characteristics of them were analyzed. Results: Thirteen patients manifested ENM restricted to the lower limb as the first seizure type, diagnosed as benign childhood focal epilepsy with vertex spikes (BEVS). Six patients had ENM as the first and only seizure type during the short-time follow-up. Among them, there were 1 male and 5 females. The age at seizure onset was (2.5±0.7) years. One of them had electrical status epilepticus during sleep (ESES) identified on electroencephalogram at theage of 4 years and 8 months. The last follow-up age was (3.8±1.5) years. The remaining 7 patients developed nocturnal focal motor seizures. Among them, there were 4 males and 3 females. The age at seizure onset was (3.5±0.7) years. Two of them were diagnosed as BEVS evolving into benign childhood epilepsy with centrotemporal spikes (BECTS) and 5 were diagnosed as BEVS concurring with BECTS. The age at focal seizures was (4.1±0.6) years. The interval ranged from 1 month to 1 years. Six of 7 patients had electrical ESES with the age of (5.2±1.0) years. All had developmental regression, further diagnosed as atypical benign partial epilepsy (ABPE). The median age at last follow-up was 5.9 years. Five of 13 patients had repeated electroencephalogram records at our apartment, showing that epileptiform discharges in midline regions were significantly reduced either in frequency or amplitude with the improvement of ENM restricted to the lower limb and that independent epileptiform discharges in Rolandic regions from midline regions were noticed with the onset of nocturnal focal seizures. Conclusions: ENM restricted to the lower limb has a close association with vertex (midline) epileptiform discharges. ENM restricted to the lower limb as the first seizure type is a peculiar phenomenon of BEVS. Some patients could evolve into BECTS or overlap with BECTS, and further into ABPE. The age of seizure onset in BEVS with ENM restricted to the lower limb as the first symptom is a little earlier than in BECTS. Ignorance of the close association between midline spikes and ENM restricted to the lower limb may lead to misdiagnosis of these patients.

Biogeochemical controls of surface ocean phosphate.

Surface ocean phosphate is commonly below the standard analytical detection limits, leading to an incomplete picture of the global variation and biogeochemical role of phosphate. A global compilation of phosphate measured using high-sensitivity methods revealed several previously unrecognized low-phosphate areas and clear regional differences. Both observational climatologies and Earth system models (ESMs) systematically overestimated surface phosphate. Furthermore, ESMs misrepresented the relationships between phosphate, phytoplankton biomass, and primary productivity. Atmospheric iron input and nitrogen fixation are known important controls on surface phosphate, but model simulations showed that differences in the iron-to-macronutrient ratio in the vertical nutrient supply and surface lateral transport are additional drivers of phosphate concentrations. Our study demonstrates the importance of accurately quantifying nutrients for understanding the regulation of ocean ecosystems and biogeochemistry now and under future climate conditions.

Membrane organization of photosystem I complexes in the most abundant phototroph on Earth.

Prochlorococcus is a major contributor to primary production, and globally the most abundant photosynthetic genus of picocyanobacteria because it can adapt to highly stratified low-nutrient conditions that are characteristic of the surface ocean. Here, we examine the structural adaptations of the photosynthetic thylakoid membrane that enable different Prochlorococcus ecotypes to occupy high-light, low-light and nutrient-poor ecological niches. We used atomic force microscopy to image the different photosystem I (PSI) membrane architectures of the MED4 (high-light) Prochlorococcus ecotype grown under high-light and low-light conditions in addition to the MIT9313 (low-light) and SS120 (low-light) Prochlorococcus ecotypes grown under low-light conditions. Mass spectrometry quantified the relative abundance of PSI, photosystem II (PSII) and cytochrome b6f complexes and the various Pcb proteins in the thylakoid membrane. Atomic force microscopy topographs and structural modelling revealed a series of specialized PSI configurations, each adapted to the environmental niche occupied by a particular ecotype. MED4 PSI domains were loosely packed in the thylakoid membrane, whereas PSI in the low-light MIT9313 is organized into a tightly packed pseudo-hexagonal lattice that maximizes harvesting and trapping of light. There are approximately equal levels of PSI and PSII in MED4 and MIT9313, but nearly twofold more PSII than PSI in SS120, which also has a lower content of cytochrome b6f complexes. SS120 has a different tactic to cope with low-light levels, and SS120 thylakoids contained hundreds of closely packed Pcb-PSI supercomplexes that economize on the extra iron and nitrogen required to assemble PSI-only domains. Thus, the abundance and widespread distribution of Prochlorococcus reflect the strategies that various ecotypes employ for adapting to limitations in light and nutrient levels.

Myocardial CT perfusion imaging and atherosclerotic plaque characteristics on coronary CT angiography for the identification of myocardial ischaemia.

AIM: To investigate the value of myocardial computed tomography (CT) perfusion imaging (CTP) and atherosclerotic plaque characteristics (APCs) identified on coronary CT angiography (CCTA) for the detection of myocardial ischaemia by using single-photon-emission CT (SPECT) as a reference. MATERIALS AND METHODS: Thirty-six patients (63.9% males) undergoing combined stress dynamic CTP and CCTA were enrolled and analysed. Myocardial blood flow (MBF) from CTP was quantified and compared between normal and abnormal segments. The ability of CTP and APCs to detect ischaemia was compared to that of SPECT. RESULTS: Nineteen patients with 78 segments had perfusion abnormalities on CTP. A significant difference was seen in MBF values between normal (118.51±27.86 ml/100 ml/min) and hypoperfused (79.60±21.35 ml/100 ml/min) segments (t=15.832, p<0.05). The sensitivity and specificity for identifying ischaemia were 90.91% and 94.97%, respectively, on a per-segment basis, resulting in a r value of 0.737 (p<0.05). On a per-vessel basis, the sensitivity and specificity for detecting ischaemia were 86.67% and 84.62%, respectively, for CTP; 93.33% and 58.97%, respectively, for CCTA; and 86.67% and 87.18%, respectively, for CTP combined with CTA, with an area under the receiver-operator characteristic curve (AUC) being 0.87 (p<0.05) and 0.887 (p<0.05) for CTP and its combination with CTA, respectively. On CCTA, 55 vessels with APCs were detected, with an AUC of 0.737 (p<0.05) for APCs combined with CCTA stenosis and 0.802 (p<0.05) for APCs combined with CTP. CONCLUSIONS: Dynamic stress CTP shows good correlation with SPECT for the detection of ischaemia. Additionally, combining APCs with CCTA stenosis has the ability to discriminate ischaemic stenosis.

Epileptic negative myoclonus restricted to lower limbs in benign childhood focal epilepsy with vertex spikes.

BACKGROUND AND PURPOSE: The aim was to determine the electroclinical findings in benign childhood focal epilepsy with vertex spikes (BEVS) with epileptic negative myoclonus (ENM) restricted to the lower limbs. METHODS: The electroencephalogram database of Peking University First Hospital and medical records of patients with BEVS and ENM restricted to the lower limbs were reviewed. RESULTS: Twenty-seven patients with BEVS had ENM restricted to the lower limbs. Twelve started as ENM restricted to the lower limbs. The age at seizure onset ranged from 1.5 to 4.8 years. During the course, half of the 12 patients developed focal sensorimotor seizures and then were diagnosed as benign childhood epilepsy with centrotemporal spikes (BECTS), with BEVS (four cases) and without BEVS (two cases). Five of them had electrical status epilepticus during sleep (ESES) and met the diagnostic criteria of atypical benign partial epilepsy (ABPE). Fifteen of the 27 patients had ENM restricted to the lower limbs during the course. The age at seizure onset ranged from 1.3 to 9.8 years. All had ESES and were diagnosed as ABPE, 11 as ABPE with BEVS and four as ABPE evolving into BEVS. CONCLUSIONS: Benign childhood focal epilepsy with vertex spikes (BEVS) might represent a specific epileptic syndrome of the continuum of benign childhood focal epilepsy. ENM restricted to the lower limbs was a special phenomenon in BEVS. BEVS could overlap with BECTS or evolve into BECTS and further into ABPE and vice versa. Ignorance of vertex spikes with associated ENM restricted to the lower limbs might lead to a misunderstanding of BEVS, a specific type of benign childhood focal epilepsy.

Pharmacological Signatures of the Exenatide Nanoparticles Against Hepatic Ischemia/Reperfusion-induced Pancreatic Injury.

BACKGROUND: Hepatic ischemia/reperfusion-induced pancreatic injury (HI/RPI) is an important pathophysiological phenomenon in clinics. Exenatide is found to have hepatopancreatic protection; however, the half-life of exenatide is extremely short, which limits its clinical application. In the present study, we described an exenatide nanocarrier based on poly(L-lysine)-poly(ethylene glycol)-poly(L-lysine) (PLL-PEG-PLL) and aimed to investigate the protective effects of exenatide/PLL-PEG-PLL on HI/RPI. METHODS: PLL-PEG-PLL was synthesized and estimated by being applied as a nanocarrier for lengthening delivery of exenatide. Exenatide was loaded into PLL-PEG-PLL by electrostatic interactions at pH 7.4. The loading and release of exenatide from PLL-PEG-PLL were characterized in vitro. The pancreatic protection of exenatide/PLL-PEG-PLL was assessed using the animal model, histopathological examination, blood biochemical indices detection, antioxidant activity, and anti-inflammatory evaluation in vivo. RESULTS: Exenatide/PLL-PEG-PLL displayed efficient loading and sustained release. Exenatide/PLL-PEG-PLL complex moderated HI/RPI and enlarged islet functionality compared to free exenatide. CONCLUSION: We propose that the nanocarrier PLL-PEG-PLL may function as a potent exenatide nanocarrier for augmenting anti-HI/RPI pharmacotherapy with unprecedented clinical benefits.

Macroecological patterns of the phytoplankton production of polyunsaturated aldehydes.

The polyunsaturated aldehydes (PUAs) are bioactive metabolites commonly released by phytoplankton species. Based primarily on laboratory experiments, PUAs have been implicated in deleterious effects on herbivores and competing phytoplankton species or in the regulation of the rates of bacterial organic matter remineralization; however, the role of the PUAs at an ecosystem level is still under discussion. Using data of PUA production in natural phytoplankton assemblages over a wide range of conditions, we analyzed macroecological patterns aiming for a comprehensive environmental contextualization that will further our understanding of the control and ecologic role played by these compounds. PUA composition changed from the predominance of decadienal in oligotrophy, octadienal in eutrophy, and heptadienal at intermediate conditions. The production of PUAs per unit biomass also showed a strong relationship with the trophic status, sharply increasing towards oligotrophic conditions and with small-sized cells reaching the highest production rates. High ratios of dissolved inorganic nitrogen to dissolved inorganic phosphorus also promoted PUA production, albeit to a considerably lesser extent. Although the allelopathic use of PUAs to outcompete other phytoplankton or reduce herbivory may be key in some environments and interactions, the macroecological patterns found here, showing higher production towards the poorest waters and among the small species typically populating these environments, support and link at the large scale the hypotheses of the nutrient-derived stress as driver for the production of PUAs together with the use of these compounds as boosters for the nutrient remineralization.

Anisotropic functionalization of upconversion nanoparticles.

Despite significant advances toward accurate tuning of the size and shape of colloidal nanoparticles, the precise control of the surface chemistry thereof remains a grand challenge. It is desirable to conjugate functional bio-molecules onto the selected facets of nanoparticles owing to the versatile capabilities rendered by the molecules. We report here facet-selective conjugation of DNA molecules onto upconversion nanoparticles via ligand competition reaction. Different binding strengths of phosphodiester bonds and phosphate groups on DNA and the surfactant molecules allow one to create heterogeneous bio-chemistry surface for upconversion nanoparticles. The tailored surface properties lead to the formation of distinct self-assembly structures. Our findings provide insight into the interactions between biomolecules and nanoparticles, unveiling the potential of using nanoparticles as fundamental building blocks for creating self-assembled nano-architectures.

[Application of scalp-recorded high-frequency oscillations in epileptic encephalopathy with continuous spike-and-wave during sleep].

OBJECTIVE: To investigate the clinical significance of high-frequency oscillations (HFOs) on scalp electroencephalography (EEG) in patients with epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS). METHODS: Twenty-one CSWS patients treated for epilepsy from January 2006 to December 2016 in Pediatric Department of Peking University First Hospital were enrolled into the study. Selected clinical variables including gender, age parameters, seizure frequencies and antiepileptic drugs were compared between (a). HFO-positive group and HFO-negative group before methylprednisolone treatment and (b). excellent seizure outcome group and not-excellent seizure outcome group after methylprednisolone treatment. Interictal HFOs and spikes in pre- and post-methylprednisolone scalp EEG were measured and analyzed. RESULTS: Before methylprednisolone treatment, there were 12 of 21 (57%) CSWS patients had HFOs, with a mean value 43.17 per 60 s per patient. The 12 patients with HFOs tended to have more frequent epileptic negative myoclonus/atonic/myoclonus/atypical absences than those without HFOs in a month before methylprednisolone treatment. A total of 518 HFOs and 22 592 spikes were found in the pre-methylprednisolone EEG data of 21 patients, and 441 HFOs (86%) were associated with spikes. The highest amplitudes of HFOs were significantly positively correlated with that of spikes (r=0.279, P<0.001). Rates reduced by methylprednisolone treatment were statistically significant for both HFOs (P=0.002) and spikes (P=0.006). The percentage of reduction was 91% (473/518) and 39% (8 905/22 592) for spikes and HFOs, respectively. The percentage of spike and HFOs changes was respectively 100% decrease and 47% decrease in the excellent seizure outcome group, and they were 79% decrease and 18% increase in the not-excellent seizure outcome group. CONCLUSION: Prevalence of HFOs might reflect some aspect of epileptic activity. HFOs were more sensitive to methylprednisolone treatment than spikes and had a good correlation with the prognosis of seizures, and HFOs could be applied to assess epilepsy severity and antiepileptic therapy.

Iron-Insensitive Quantitative Assessment of Subcortical Gray Matter Demyelination in Multiple Sclerosis Using the Macromolecular Proton Fraction.

BACKGROUND AND PURPOSE: Fast macromolecular proton fraction mapping is a recent quantitative MR imaging method for myelin assessment. The objectives of this study were to evaluate the macromolecular proton fraction as a measure of demyelination in subcortical GM structures in multiple sclerosis and assess a potential relationship between demyelination and excess iron deposition using the macromolecular proton fraction and T2* mapping. MATERIALS AND METHODS: Macromolecular proton fraction and T2* maps were obtained from 12 healthy controls, 18 patients with relapsing-remitting MS, and 12 patients with secondary-progressive MS using 3T MR imaging. Parameter values in the caudate nucleus, globus pallidus, putamen, substantia nigra, and thalamus were compared between groups and correlated to clinical data. RESULTS: The macromolecular proton fraction in all subcortical structures and T2* in the globus pallidus, putamen, and caudate nucleus demonstrated a significant monotonic decrease from controls to patients with relapsing-remitting MS and from those with relapsing-remitting MS to patients with secondary-progressive MS. The macromolecular proton fraction in all subcortical structures significantly correlated with the Expanded Disability Status Scale and MS Functional Composite scores with absolute Pearson correlation coefficient (r) values in a range of 0.4-0.6. Significant correlations (r = -0.4 to -0.6) were also identified between the macromolecular proton fraction and the 9-Hole Peg Test, indicating a potential relationship with nigrostriatal pathway damage. Among T2* values, weak significant correlations with clinical variables were found only in the putamen. The macromolecular proton fraction did not correlate with T2* in any of the studied anatomic structures. CONCLUSIONS: The macromolecular proton fraction provides an iron-insensitive measure of demyelination. Myelin loss in subcortical GM structures in MS is unrelated to excess iron deposition. Subcortical GM demyelination is more closely associated with the disease phenotype and disability than iron overload.

Phylogenetic and genomic characterization of a novel atypical porcine pestivirus in China.

Atypical porcine pestivirus (APPV) has been considered a novel pestivirus and causative agent of congenital tremor type A-II. An APPV CH-GX2016 strain was characterized from newly born piglets with clinical symptoms of congenital tremor in Guangxi, China. The genome of APPV CH-GX 2016 strain was 11,475 bp in length and encoded a polyprotein composed of the 3,635 amino acids. This genome sequence exhibited 88.0% to 90.8% nucleotide sequence homology with other APPV reference sequences in GenBank. Phylogenetic analysis further showed that APPV CH-GX is a novel pestivirus compared with previously described classical pestivirus strains. Therefore, APPV is present in pigs in China.

Identification and genetic characterization of porcine circovirus type 3 in China.

A novel circovirus called porcine circovirus type 3 (PCV3) was recently reported to exist in the USA. This circovirus is associated with porcine dermatitis, nephropathy syndrome and reproductive failure. This study reports on the first identification, widely epidemic, different phylogenetic clusters, potential role in sow reproductive failure and possible origins of PCV3 in China.