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1.
Sci Total Environ ; 754: 141848, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32898778

RESUMO

In this work, polyvinylidene fluoride (PVDF) loose nanofiltration (NF) hollow fiber membranes with multilayer structure were prepared successfully based on a solvent-free process. Graphene oxide (GO) was used to cover the interface pores of the pristine PVDF membranes via vacuum filtration, and polypyrrole (PPy) was polymerized on the surface to further decorate the membrane structure. Interestingly, the modified membranes exhibited a multilayer structure due to synergistic effect of GO and PPy. The structure and property of PVDF loose NF membranes were investigated in detail. After modifying by GO and PPy, the hydrophilicity improved obviously. Moreover, the molecular weight cut off (MWCO) was about 3580 Da, and the smallest pore size of skin layer decreased to 2.5-4 nm. Furthermore, the PVDF loose NF hollow fiber membranes presented a high dye rejection (˃98.5%) for negative dyes, whereas a low salt rejection for NaCl (about 4%), showing a great potential for separating dye/salt accurately. Specifically, there were not any solvent used in all the preparation processes. The work offered a novel strategy for green preparation of loose NF membranes.

2.
Sci Total Environ ; 750: 141667, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32871370

RESUMO

Stable isotopes are increasingly used to detect and understand the impacts of environmental changes on riverine ecological properties. The δ13C and δ15N signatures of fish with different feeding habits were measured in a large subtropical river to evaluate how fish isotopic niches respond to environmental gradients and human disturbance. From basal resources to fish consumers, the high values of epilithic periphyton (biofilm) δ13C and suspended particulate organic matter δ15N concurrently determined the niche ranges and space (e.g., convex hull area) of fish communities. Along a longitudinal gradient (except in the industrial zone), the number of fish trophic guilds identified by Bayesian ellipses continuously increased; meanwhile, higher trophic diversity and less redundancy were observed near the lower reaches and estuary. Variance inflation factors were estimated to detect the multicollinearity of 40 environmental variables, 14 of which were selected as indicators. Relative importance (RI) analysis was used to evaluate the explanatory power of these indicators for the spatial variation in isotopic niche metrics; the results showed that riffle habitat area, water nitrate concentration, gravel-cobble substrate, and riparian buffer width were the 4 key environmental indicators (average RI > 12%) that determined the longitudinal pattern of fish isotopic niches. These findings suggested that community-level δ13C signatures are more responsive to changes in habitats (e.g., riffle) and substrates (e.g., gravel-cobble) supporting the productivity of autochthonous diatoms while δ15N signatures respond to water quality altered by nitrogen pollution from manure-fertilized farming and poultry livestock effluent. Furthermore, δ15N may be more robust and interpretable than δ13C as an isotopic indicator of ecosystem change in rivers exposed to multiple or complex anthropogenic stressors.


Assuntos
Ecossistema , Rios , Animais , Teorema de Bayes , Isótopos de Carbono/análise , China , Indicadores Ambientais , Monitoramento Ambiental , Humanos , Isótopos de Nitrogênio/análise
3.
J Hazard Mater ; 401: 123747, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33113730

RESUMO

This study pays a special attention to three phenolic endocrine disrupting compounds (EDCs), - bisphenol A (BPA), 4-nonylphenol (4-NP), and 4-tert-octylphenol (4-t-OP) - that are present in urban environments, resultant of several anthropogenic activities that can be also carried through rainfall runoff. We investigated the distributions of BPA, 4-NP, and 4-t-OP in Pearl River basin and estimated the mass loads in rainfall runoff, wastewater treatment plant (WWTP) effluents, and industrial wastewater from urbanized Huizhou and Dongguan regions. These three phenolic EDCs were detected frequently in tributaries and mainstream of Dongjiang River with the maximum 4-NP concentrations of 14,540 ng/L in surface waters and 3088 ng/g in sediments. BPA showed high concentrations in rainfall runoff samples with maximum concentrations of 5873 and 2397 ng/L in Huizhou and Dongguan regions, respectively, while concentrations for 4-NP and 4-t-OP were detected at tens to hundreds of nanograms per liter. Mass loads of phenolic EDCs from rainfall runoff were 3-62 times higher than those of WWTP effluents, suggesting rainfall runoff is an important source of phenolic EDCs into receiving waters. Sources and tributaries showed median to high estrogenic risks, while low to median risks were found in mainstream, implying the source control should be focused.

4.
Zhongguo Dang Dai Er Ke Za Zhi ; 22(11): 1209-1214, 2020 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-33172557

RESUMO

OBJECTIVE: To observe the incidence of malnutrition and nutritional risk in children with pneumonia on mechanical ventilation in the pediatric intensive care unit (PICU), and to explore the nutritional support effect of short-peptide enteral nutrition formula. METHODS: A total of 68 children with severe pneumonia who were hospitalized in the PICU from October 2017 to October 2018 and required mechanical ventilation were enrolled for a prospective randomized controlled study. The children were randomly divided into a control group and an experimental group. Through the nasogastric feeding tube, the experimental group received the short-peptide enteral nutrition formula, and the control group received the intact-protein enteral nutrition formula. The weight-for-age Z score, STRONGkids nutritional risk score, and pediatric critical illness score of the two groups were evaluated. The serum levels of total protein, albumin, and prealbumin (PA) on admission and before discharge were measured. The gastrointestinal tolerance and clinical outcome indicators of the two groups were observed. RESULTS: Among the 68 mechanically ventilated children, 26 (38%) had malnutrition, including moderate malnutrition (10 cases, 15%) and severe malnutrition (16 cases, 24%); 10 cases (15%) had malnutrition at discharge. Sixty-three children (93%) had nutritional risk, including moderate nutritional risk in 21 cases and high nutritional risk in 42 cases. The moderate and high nutritional risk rates of the critical and extreme critical groups were significantly higher than those of the non-critical group (P<0.05). Compared with the control group, the experimental group had significantly shorter duration of mechanical ventilation and total length of hospital stay, significantly higher serum PA level and weight growth rate, and significantly better gastrointestinal tolerance (P<0.05). There were no significant differences in the incidence of ventilator-associated pneumonia and disease outcome between the two groups (P>0.05). CONCLUSIONS: The detection rates of malnutrition and nutritional risk in children with pneumonia on mechanical ventilation are relatively high. Short-peptide enteral nutrition formula can help improve their treatment outcome and are more suitable for nutritional support in critically ill children on mechanical ventilation.

5.
eNeuro ; 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33229412

RESUMO

Myosin Va (MyoVa) is a plus-end filamentous-actin motor protein that is highly and broadly expressed in the vertebrate body, including in the nervous system. In excitatory neurons MyoVa transports cargo toward the tip of the dendritic spine, where the post-synaptic density (PSD) is formed and maintained. MyoVa mutations in humans cause neurological dysfunction, intellectual disability, hypomelanation and death in infancy or childhood. Here we characterize the Flailer (Flr) mutant mouse, which is homozygous for a myo5a mutation that drives high levels of mutant MyoVa (Flr protein) specifically in the CNS. Flr protein functions as a dominant-negative MyoVa, sequestering cargo and blocking its transport to the PSD. Flr mice have early seizures and mild ataxia, but mature and breed normally. Flr mice display several abnormal behaviors known to be associated with brain regions that show high expression of Flr protein. Flr mice are defective in the transport of synaptic components to the PSD and in mGluR-dependent LTD and have a reduced number of mature dendritic spines. The synaptic and behavioral abnormalities of Flr mice result in an anxiety and memory deficits similar to that of other mouse mutants with Obsessive-compulsive disorder and Autism spectrum disorder (ASD). Because of the dominant-negative nature of the Flr protein, the Flr mouse offers a powerful system for the analysis of how the disruption of synaptic transport and lack of LTD can alter synaptic function, development and wiring of the brain and result in symptoms that characterize many neuropsychiatric disorders.SIGNIFICANCE STATEMENT Here we characterize a mutant mouse homozygous for a Myosin Va mutation named Flailer. The Flailer mutation generates a dominant-negative MyoVa transport motor protein that sequesters synaptic cargo and blocks synaptic transport, thereby resulting in an absence of LTD and in abnormal behaviors similar to those seen in anxiety and Autism Spectrum disorders. We propose that the Flailer mutant can be used as a model to study how the absence of LTD disrupts brain connectivity and behavior. Moreover, by using the Flailer mutation together with gene editing technologies it should be possible to target specific brain areas to remove the mutation and recover MyoVa function, thereby interrogating the role of a specific brain region in the control of a particular behavior.

6.
J Exp Bot ; 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33130852

RESUMO

Malonyl-CoA:flavonoid acyltransferases (MaT) modify isoflavones, but only a few have been characterized for activity and assigned to specific physiological processes. Legume roots exude isoflavone malonates into the rhizosphere, where they are hydrolyzed into isoflavone aglycones. Soybean GmMaT2 was highly expressed in seeds, root hairs, and nodules. GmMaT2 and GmMaT4 recombinant enzymes used isoflavone 7-O-glucosides as acceptors and malonyl-CoA as an acyl donor to generate isoflavone glucoside malonates. GmMaT2 had higher activity towards isoflavone glucosides than GmMaT4. Overexpression (OE) in hairy roots of GmMaT2 and 4 produced more malonyldaidzin, malonylgenistin, and malonylglycitin, and resulted in more nodules than control. However, only GmMaT2 knockdown (KD) hairy roots showed reduced levels of malonyldaidzin, malonylgenistin, and malonylglycitin, and likewise, reduced nodule numbers. These were consistent with the up-regulation of only GmMaT2 by rhizobial infection, and higher expression levels of early nodulation genes in GmMaT2- and 4-OE, but lower only in GmMaT2-KD roots compared to control roots. Higher malonyl isoflavonoid levels in transgenic hairy roots were associated with higher levels of isoflavones in root exudates and more nodules, and vice versa. We posit that GmMaT2 participates in soybean nodulation by catalyzing isoflavone malonylation and affecting malonyl isoflavone secretion for activation of Nod factor and nodulation.

7.
Mol Med Rep ; 22(6): 4725-4733, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33174002

RESUMO

Spinal cord injury (SCI) is a devastating disorder that often results in temporary and/or permanent functional impairment below the injured level. To date, few satisfactory therapeutic strategies are available to treat SCI. Hence, exploring novel strategies for SCI is an essential public health concern. Cell transplantation therapy, which is associated with neuroprotection, immunomodulation, axon regeneration, neuronal relay formation and myelin regeneration, provides a promising therapeutic strategy for SCI. The neuronal stem cell (NSC) preconditioning method is an emerging approach, which facilitates NSC survival and neuronal differentiation after implantation. The aim of the present study was to develop a feasible candidate for cell­based therapy following SCI in rats and to investigate the role of high mobility group box­1 (HMGB1) in NSC activation. The results of the present study showed that transplantation of NSCs, preconditioned with 1 ng/ml HMGB1, facilitated functional improvement of injured spinal cords, as indicated by Basso, Beattie and Bresnahan mean scores, mechanical hypersensitivity and cold stimulation. Meanwhile, the histological examination of hematoxylin and eosin staining indicated that engraftment of HMGB1­preconditioned NSCs resulted in decreased atrophy of the injured spinal cord. Meanwhile, the transplantation of HMGB1­preconditioned NSCs resulted in an increased number of functional Nissl bodies in neurons, as detected by Nissl staining, and an increase in the number of ßIII­tubulin+ cells in the epicenter of injured spinal cords in rats with SCI. In addition, the results also demonstrated that 1 ng/ml HMGB1 promoted the differentiation of NSCs into neurons, and that the ERK signaling pathway played an important role in this process. In conclusion, the present data indicated that the preconditioning strategy with 1 ng/ml HMGB1 may present a feasible candidate for cell­based therapy following SCI in rats, which may enlarge the scope of HMGB1 in NSC activation.

8.
Artigo em Inglês | MEDLINE | ID: mdl-33177378

RESUMO

PURPOSE: The aim of this study was to validate and compare the prognostic performance of the albumin-bilirubin (ALBI) grade, platelet-albumin-bilirubin (PALBI) grade, Child-Pugh (CP) grade, and Model for End-Stage Liver Disease (MELD) score in predicting the 1-year variceal rebleeding probability using artificial intelligence for patients with cirrhosis and variceal bleeding undergoing early transjugular intrahepatic portosystemic shunt (TIPS) procedures. MATERIALS AND METHODS: This dual-center retrospective study included two cohorts, with patients enrolled between January 2016 and September 2018 in the training cohort and January 2017 and September 2018 in the validation cohort. In the training cohort, independent risk factors associated with the 1-year variceal rebleeding probability were identified using univariate and multivariate logistic analyses. ALBI-, PALBI-, Child-Pugh-, and MELD-based nomograms and an artificial neural network (ANN) model were established and validated internally in the training cohort and externally in the validation cohort, which included patients with variceal bleeding who were treated with preventive TIPS. RESULTS: A total of 259 patients were included. The median follow-up periods were 24.1 and 18.9 months, and the 1-year variceal rebleeding rates were 12.3% (14/114) and 10.3% (15/145) in the training and validation cohorts, respectively. In the training cohort, all four variables were identified as independent risk factors. Four nomograms were then established and showed comparable prognostic performances after internal (C-index: 0.879, 0.829, 0.874, and 0.798) and external (C-index: 0.720, 0.719, 0.718, and 0.703) validation. The ANN demonstrated that these four variables had comparable importance in predicting the 1-year variceal rebleeding probability. CONCLUSION: None of the four variables are optimal in predicting the 1-year variceal rebleeding probability for patients with cirrhosis and variceal bleeding undergoing early TIPS.

9.
Eur J Obstet Gynecol Reprod Biol ; 255: 183-189, 2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33147530

RESUMO

OBJECTIVE: To explore the effects of two functional genetic variants of poly(ADP-ribose) polymerase-1 (PARP-1) on the susceptibility to epithelial ovarian cancer (EOC), the platinum-based chemotherapeutic response, and the prognosis of northern Chinese patients. STUDY DESIGN: This case-control study included 710 EOC patients in the case group and 700 healthy women in the control group. Two polymorphisms (rs1136410 and rs8679) of PARP-1 were genotyped by polymerase chain reaction and ligase detection reaction. RESULTS: The genotype frequencies of rs1136410 and rs8679 were not significantly different between the case and control groups. However, the CC genotype of rs1136410 was significantly associated with a favorable response to platinum drugs. Compared with the TT genotype, the CC genotype of rs1136410 was related to a reduced risk of platinum resistance (adjusted OR: 0.40; 95% CI = 0.24-0.67; P = 0.001). In addition, multivariable analysis containing clinical variables showed that patients who carried the rs1136410 CC genotype had a significantly improved progression-free survival compared with patients who carried the TT genotype (HR = 0.67, 95% CI = 0.47-0.97, P = 0.031). CONCLUSION: The rs1136410 polymorphism may serve as a potential marker for predicting the response to platinum agents and prognosis of EOC patients treated with surgery and platinum-based chemotherapy.

10.
Proc Biol Sci ; 287(1938): 20202172, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33171081

RESUMO

Foraging animals must balance benefits of food acquisition with costs induced by a post-prandial reduction in performance. Eating to satiation can lead to a reduction in locomotor and escape performance, which increases risk should a threat subsequently arises, but limiting feeding behaviour may be maladaptive if food intake is unnecessarily reduced in the prediction of threats that do not arise. The efficacy of the trade-off between continued and interrupted feeding therefore relies on information about the future risk, which is imperfect. Here, we find that black carp (Mylopharyngodon piceus) can balance this trade-off using an a posteriori strategy; by eating to satiation but regurgitating already ingested food when a threat arises. While degrees of satiation (DS) equal to or greater than 60% reduce elements of escape performance (turning angle, angular velocity, distance moved, linear velocity), at 40% DS or lower, performance in these tasks approaches levels comparable to that at 0% satiation. After experiencing a chasing event, we find that fish are able to regurgitate already ingested food, thereby changing the amount of food in their gastrointestinal tract to consistent levels that maintain high escape performance. Remarkably, regurgitation results in degrees of satiation between 40 and 60% DS, regardless of whether they had previously fed to 40, 60 or 100% DS. Using this response, fish are able to maximize food intake, but regurgitate extra food to maintain escape performance when they encounter a threat. This novel strategy may be effective for continual grazers and species with imperfect information about the level of threat in their environment.

11.
Food Chem ; : 128532, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33172752

RESUMO

An accurate and sensitive analytical method for detecting and quantifying reducing sugar ends (RSE) in chitooligosaccharides (COSs) is the key quality parameter for evaluating their structure-function relationship and potential applications. In this work, we develop and validate a novel colorimetric assay with high accuracy and precision for determining RSE content using 3-methyl-2-benzothiazolinone hydrazone (MBTH). Under optimal conditions, the stoichiometry is verified using mono-, di-, and tri- glucosamine hydrochlorides, and the dilution ratio does not interfere with the RSE content measured at 590 nm. The regression equation of glucosamine reveal a good linear relationship (R2 = 0.9999). The detection limit, quantification limit, mean relative standard deviation (RSD), and recovery are 2.28 µM, 9.11 µM, 1.90%, and 98.0%, respectively. The newly developed method is potentially useful for monitoring COS hydrolysis, number average molecular weight, and chitosanase activity.

12.
Forensic Sci Int ; 317: 110482, 2020 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-33142211

RESUMO

Diatom test is the most commonly used method to diagnose drowning in forensic laboratories. However, microscopic examination and identification of diatom frustules is time-consuming and requires taxonomic expertise. At present, the identification of drowning is still a challenge in forensic casework. In this study, we developed a novel diatom microarray based on the detection of specific 18S rRNA gene fragments of diatom species. The array covers 169 diatom species which were documented as commonly found in a wide range of fresh waters in China. Diatom arrays were prepared from species specific oligonucleotide probes targeting to variable regions of the 18S rRNA gene. We also developed an auxiliary sample preparation method for isolation of diatom DNA from tissues, which enabled detection of diatom species in real forensic samples as well as environmental waters. We applied the diatom arrays to analyze six drowned cases and eight environmental samples. The diatom arrays showed much better sensitivity and more consistent results than those of the conventional SEM methods. We discovered major discrepancies between results generated by the diatom arrays and the routinely used SEM based diatom tests. We verified the results of our diatom arrays by species specific PCR and Sanger sequencing and found that the currently used SEM diatom test method has a serious deficiency in sensitivity due to high loss rate of frustules in the sample preparation procedure. We anticipate that the application of diatom arrays will transform current forensic practice of diagnosing drowning deaths.

13.
Lasers Surg Med ; 2020 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-33161594

RESUMO

BACKGROUND AND OBJECTIVES: 5-Aminolevulinic acid (5-ALA) is a porphyrin-based photosensitizer and has been used for photodynamic therapy of cervical intraepithelial neoplasia (CIN). In this study, photodetection and safety of 5-ALA-induced porphyrin in CIN tissues were assessed. STUDY DESIGN/MATERIALS AND METHODS: A total of 42 patients for whom colposcopy or loop electrosurgical excision procedure (LEEP) was planned were administered 10%, 20%, or 30% 5-ALA locally on the surface of the cervix for 1.5-18 hours. At different times after application, the fluorescence intensity of 5-ALA-induced porphyrin on CIN and non-CIN lesions of the cervix was detected. RESULTS: Fluorescence intensity was correlated with drug concentration and application time. With 20% 5-ALA, the porphyrin fluorescence intensity increased over time, reaching a peak after 6 hours of application intervals in CIN. There was no significant difference in fluorescence intensity between CIN lesions and chronic cervicitis (benign tissue) or among CIN lesions of different severities. Three adverse events were considered related to the drug; however, these had no significant correlation with the drug concentration or application time. CONCLUSIONS: 5-ALA at 10%-30% concentration is safe in patients with CIN. For further treatment, we recommend the application of 20% 5-ALA, 6 hours before photodynamic therapy in CIN. CLINICAL TRIAL REGISTRATION: This study was registered at http://www.chinadrugtrials.org.cn (registration number: CTR20130326) in accordance with the requirements of the National Medical Products Administration in China. Considering that there is no English version of the above website, we made a retrospective registration on http://www.chictr.org.cn (registration number ChiCTR1800016755) in 2018. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

14.
Vascul Pharmacol ; : 106821, 2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33221530

RESUMO

BACKGROUND: Vascular calcification (VC) is associated with the high morbidity and mortality of cardiovascular diseases in dialysis patients and is a process in which vascular smooth muscle cells (VSMCs) actively differentiate into osteoblast-like cells. Reticulocalbin-2 (RCN2) is involved in the process of osteogenic differentiation under diabetic conditions, but its regulatory role under hyperphosphatemic conditions and the related mechanisms remain unclear. In this study, the importance of the interactions among RCN2, STAT3 and miR-155-5p during the osteogenic differentiation and calcification of human aortic VSMCs (HASMCs) were investigated. METHODS: RCN2 was measured in femoropopliteal artery plaque specimens from 6 peripheral arterial disease (PAD) patients with chronic kidney disease (CKD) and 6 PAD patients without CKD. RCN2 protein and mRNA expression were assessed in the high phosphate-induced aortic rings culture ex vivo model. In vitro calcification assays and molecular mechanism studies were performed in HASMCs. RESULTS: Immunohistochemical staining results revealed increased RCN2 expression in the calcified plaques of femoral arteries of patients with CKD and in a high phosphate-induced aortic culture ex vivo model. RCN2 promoted HASMCs osteogenic differentiation and calcification by inducing STAT3 phosphorylation. Furthermore, inhibition of STAT3 activation by cryptotanshinone (CT) promoted miR-155-5p expression in HASMCs. In turn, miR-155-5p inhibited RCN2 mRNA expression, while RCN2 overexpression partially offset the miR-155-5p-mediated inhibition of HASMC calcification, acting as a positive feedback loop. CONCLUSION: These results demonstrate that RCN2 is a crucial regulator of VC under hyperphosphatemic conditions. RCN2/STAT3/miR-155-5p feedback loop is important in VC and targeting each member of this feedback loop could potentially reverse high phosphate-induced VC.

15.
J Hazard Mater ; : 124356, 2020 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-33158645

RESUMO

Foliar uptake of Pb is especially important when Chinese cabbage (Brassica rapa spp. pekinensis), having a large leaf surface area, is cultivated in North China during seasons with heavy haze. However, the mechanisms of foliar Pb uptake via stomata by Chinese cabbage exposed to atmospheric fallout are unclear. A field experiment was conducted to explore the impacts of Pb in particulate matter with sizes ≤ 2.5 µm (PM2.5-Pb) from atmospheric fallout to Pb accumulation in cabbage leaves through stomata. Cabbage varieties with low-Pb-accumulation (LPA) and high-Pb-accumulation (HPA) were examined using inductively coupled plasma-mass spectrometry and scanning electron microscopy/energy-dispersive X-ray analysis. The 206Pb/207Pb and 208Pb/207Pb ratios of PM2.5, plants, and soil demonstrated that the major source of Pb in cabbage leaves was PM2.5. The average width and length of the stomatal apertures were 7.14 and 15.61 µm for LPA cabbage and 8.10 and 16.64 µm for HPA cabbage, which are large enough for PM2.5-Pb to enter the leaves. The HPA cabbage had significantly higher stomatal width-to-length ratios than the LPA cabbage, indicating that the former trapped much more PM2.5-Pb and accumulated more Pb. These results clarify the contributions of the stomatal characteristics to PM2.5-Pb accumulation in the edible parts of Chinese cabbage.

16.
J Hazard Mater ; : 124357, 2020 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-33158648

RESUMO

Microplastics are small plastic pieces with sizes less than 5 mm. Due to their widespread distribution in different environmental compartments, food, and drinking water, microplastics have attracted increasing attention across the world. Previous reports have focused on the source, distribution, fate, and toxicity of microplastics. However, many of these studies and reviews are not quite comprehensive, and most of them have only focused on marine environments. Therefore, we comprehensively reviewed the available literature on the source, occurrence, and fate of microplastics in different environments, including air, freshwater, soil, and ocean, across the world. Our review suggests that the sources of microplastics are extensive and diverse and that their occurrence, transport, and fate in the environment are affected by a variety of natural factors as well as their own physicochemical properties. Studies on the toxicological effects of microplastics are also reviewed. We found that large research gaps exist in the quantitative analysis of different exposure routes of microplastics, and microplastic toxicity to organisms. Moreover, key suggestions for future research are presented, and we call for more efforts focusing on the occurrence and fate of microplastics in terrestrial environments, especially in the atmosphere and soil, and further investigations on the toxicity mechanisms of microplastics.

17.
J Chem Theory Comput ; 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33231445

RESUMO

A major field of current research in chemistry and biology is the development of the tools that enable in situ analysis of complex systems. However, the long-time dynamics simulation for an extremely large system in solution is almost impossible by an all-atom force field combined with an explicit solvent model. The results show that the larger the periodic box is, the closer the properties of the system are to the experimental values. Therefore, how can we carry out simulations for systems that are fast, accurate, and large enough? A method of dividing the periodic box into subdivisions with their surroundings (DBSS) is presented here, and it clearly increases the computation speed without losing accuracy and enables the simulation of extremely large systems by strongly decreasing the dimension of the charge matrix. The DBSS method divides a single periodic box or unit in an extremely large system into several subdivisions with a suitable choice according to atomic coordinates. This method ensures that these subdivisions are always changing and allows the atoms to communicate with each other. Intermolecular communication is important for molecular properties and functions but is not possible with other fragment methods. The partial charges are calculated in each subdivision with an overlapping surrounding used to take hydrogen bond interaction between the subdivisions into account. This is an iterative process because the charge population will be recalculated at intervals during the dynamics simulations. Taking a water system as an example, each subdivision is extended by 4 Å as the surrounding. The computation time scales almost linearly with the size of the system, and the slope is small. MD simulations for several properties have been performed by the ABEEM-DBSS method. The results indicate that the ABEEM-DBSS method can accurately simulate the properties of water system, and the accuracy can reach or approach that of the experimental data or of other water potentials. Interestingly, the properties become closer to the experimental data as the sizes of the periodic box increase, further validating the need for the simulation of a large system and demonstrating the value of the DBSS method.

18.
Artigo em Inglês | MEDLINE | ID: mdl-33112751

RESUMO

In order to quickly discover the low-dimensional representation of high-dimensional noisy data in online environments, we transform the linear dimensionality reduction problem into the problem of learning the bases of linear feature subspaces. Based on that, we propose a fast and robust dimensionality reduction framework for incremental subspace learning named evolutionary orthogonal component analysis (EOCA). By setting adaptive thresholds to automatically determine the target dimensionality, the proposed method extracts the orthogonal subspace bases of data incrementally to realize dimensionality reduction and avoids complex computations. Besides, EOCA can merge two learned subspaces that are represented by their orthonormal bases to a new one to eliminate the outlier effects, and the new subspace is proved to be unique. Extensive experiments and analysis demonstrate that EOCA is fast and achieves competitive results, especially for noisy data.

19.
Medicine (Baltimore) ; 99(43): e21838, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33120726

RESUMO

RATIONALE: The misplaced cervical screw can cause catastrophic surgical complications, such as nerve root damage, vertebral artery compromise, spinal cord injury, and even paraplegia. Thus, the present study aims to describe a novel technique of 3-dimensional printing model (3DPM) combined with 3-dimensional fluoroscopic navigation (3DFN) to facilitate C2 pedicle screw insertion. PATIENT CONCERNS: A 56-year-old male patient presented hypoesthesia of the trunk and extremities, accompanied by a walking disorder. DIAGNOSES: Congenital atlantoaxial malformation with atlantoaxial dislocation. INTERVENTIONS: He underwent an occipital cervical fusion. We used 3DPM and 3DFN technology to guide C2 pedicle screws insertion. OUTCOMES: We inserted 2 pedicle screws and 4 lateral mass screws using the combined 3DPM and 3DFN technology. All screws were classified as excellent position postoperatively. The surgical duration, total fluoroscopic time, and the bleeding volume were 258 minutes, 3.9 minutes, and 237 mL, respectively. No surgical complications, such as neurological compromise, nonunion, dysphagia, infection, polypnea, fixation failure, pseudarthrosis formation, or revision surgery, were observed. The follow-up duration lasted 30 months. LESSONS: The combination of 3DPM and 3DFN to promote C2 pedicle screws implantation is a safe, accurate, reliable, and useful technology, which can achieve an excellent therapeutic effect and avoid surgical complications. However, using the 3DPM and 3DFN technology may increase the financial burden of patients.


Assuntos
Articulação Atlantoaxial/diagnóstico por imagem , Articulação Atlantoaxial/cirurgia , Fluoroscopia , Parafusos Pediculares , Impressão Tridimensional , Fusão Vertebral/métodos , Cirurgia Assistida por Computador , Articulação Atlantoaxial/anormalidades , Perda Sanguínea Cirúrgica , Humanos , Imageamento Tridimensional , Complicações Intraoperatórias/prevenção & controle , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/cirurgia , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia
20.
Respir Physiol Neurobiol ; 284: 103559, 2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-33099042

RESUMO

PURPOSE: Continuous positive airway pressure (CPAP) is the current gold-standard treatment for moderate to severe obstructive sleep apnea (OSA), and upper airway anatomy plays an increasingly important role in evaluating the efficacy of CPAP therapy. The aim of this observational study was to investigate the influence of upper airway anatomy on CPAP titration in OSA patients assessed by computed tomography (CT) during Müller's maneuver. METHODS: Consecutive patients under investigation for OSA by undergoing polysomnography and CT scan of the upper airway while awake were enrolled. Successful full-night manual titration was performed to determine the optimal CPAP pressure level for OSA patients in supine position using a nasal mask. RESULTS: A total of 157 subjects (134 males and 23 females) were included. Both apnea-hypopnea index (AHI) and LaSO2 significantly correlated with CPAP titration level, upper airway length (UAL), distance from mandibular plane to hyoid bone (MPH), and neck circumference (all p < 0.05). There were significant positive correlations between CPAP titration level and UAL (r = 0.348, p = 0.000) and MPH (r = 0.313, p = 0.002). Stepwise multiple linear regression analyses were performed to evaluate the independent predictors of AHI, LaSO2, and CPAP titration level. CPAP titration level was identified as an independent explanatory variable for AHI and LaSO2 after adjustment for confounders. Multiple linear regression analyses also indicated that body mass index (BMI) and UAL were independently associated with CPAP titration level (all p < 0.05). CONCLUSIONS: Upper airway abnormalities combined with anthropometric parameters play important roles in CPAP titration for OSA patients, providing additional insight into the factors influencing OSA treatment strategies. UAL and BMI should be taken into consideration when choosing CPAP titration level to improve CPAP compliance.

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