Recently, the number of patients with coronavirus disease 2019 (COVID-19) who have tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), via the reverse transcription ...polymerase chain reaction (RT-PCR) test, after recovery has increased; this has caused a dilemma regarding the medical measures and policies. We evaluated the dynamics of viral load and anti-SARS-CoV-2 antibodies in four patients with positive RT-PCR results after recovery. In all patients, the highest levels of immunoglobulin G (IgG) and IgM antibodies were reached after about a month of the onset of the initial symptoms. Then, the IgG titers plateaued, and the IgM titers decreased, regardless of RT-PCR results. The IgG and IgM levels did not increase after the post-negative positive RT-PCR results in any of the patients. Our results reinforced that the post-negative positive RT-PCR results may be due to the detection of RNA particles rather than reinfection in individuals who have recovered from COVID-19.
Cerebral ischemic stroke is one of the leading causes of death and disability worldwide. 2'-fucosyllactose (2'-FL), a human milk oligosaccharide, exerts anti-inflammatory effects and plays a ...protective role in arterial thrombosis; however, its role in ischemic stroke remains unclear. This study aimed to investigate the neuroprotective effects of 2'-FL and its potential mechanisms in a mouse model of ischemic stroke. Neurological score and behavior tests revealed that 2'-FL promoted the recovery of neurological deficits and motor function in middle cerebral artery occlusion (MCAO) mice, and that 2'FL led to a reduction in the size of cerebral infarct. Biochemical studies showed that administration of 2'-FL led to a reduction of reactive oxygen species (ROS)-related products in the brain of MCAO mice. 2'-FL upregulated IL-10 and downregulated TNF-α level. In addition, 2'-FL enhanced M2-type microglial polarization and upregulated CD206 expression at 7 days after MCAO. At 3 days after MCAO, 2'-FL increased IL-4 levels and activated STAT6. Our data show that 2'-FL reduced the neurological symptoms of ischemic stroke and ROS accumulation in the brain through IL-4/STAT6-dependent M2-type microglial polarization in MCAO mice. These results demonstrate that 2'-FL is a potentially effective therapeutic agent for ischemic stroke.
Polyvinyl alcohol (PVA)/carboxymethyl cellulose (CMC) hydrogels containing various CMC concentration of 2 to 10 wt% are prepared using cyclic freezing/thawing and subsequent
γ
-ray irradiation to ...evaluate the effect of CMC content on cell growth rate of the hydrogels. A 3-D porous network structure is successfully formed
via
physical and chemical crosslinking. The pore size and the metronidazole drug release rate of the PVA/CMC hydrogels increase with raising the CMC concentration from 2 to 10 wt%, however, the structural integrity is severely damaged. The highest compressive strength of 99.2 ± 9.6 kPa and the fastest cell growth determined by scratch assay and enzyme-linked immunosorbent assay are observed for the irradiated PVA/6 wt% CMC hydrogels, indicating that they are highly suitable for wound dressing requiring fast regeneration.
In rice paddy, the closed chamber method is broadly used to estimate methane (CH.sub.4) emission rate. Since rice plants can significantly affect CH.sub.4 production, oxidation and emission, rice ...plantation inside the chamber is standardized in IPCC guidelines. Methane emission rate is calculated using the increased concentration inside the headspace. Biomass growth might decrease the headspace volume, and thus CH.sub.4 emission rates might be overestimated. To evaluate the influence of chamber headspace decreased by rice plant development on CH.sub.4 emission rates, five Korean rice cultivars were cultivated in a typical rice paddy, and physical volume changes in rice biomass were assayed using water displacement method. The recommended acrylic closed chambers (H. 1.2 m x W. 0.6 m x L. 0.6 m) were installed, and eight rice plants were transplanted inside the chamber with the same space interval with the outside. Biomass growth significantly decreased the headspace volume of the chamber. However, this volume covered only 0.48-0.55% of the closed chamber volume at the maximum growth stage. During the whole cropping period, mean 0.24-0.28% of chamber headspace was allocated by plant biomass, and thus this level of total CH.sub.4 emissions was overestimated. However, this overestimation was much smaller than the errors coming from other investigation processes (i.e., chamber closing hour, temperature recording, inconstant flooding level, different soil environments, etc.) and rice physiological changes. In conclusion, the influence of physical biomass volume inside the closed chamber was negligible to make the error in total CH.sub.4 emission assessment in rice paddies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Field-emitted electron beams from nanometer-scale materials like carbon nanotubes (CNTs) have the potential to regenerate electron source devices based on performance, form factor, and usability. ...Practically, digital X-ray tubes fabricated with strongly adhesive CNT paste-emitters produce very short and exact X-ray pulses compared with conventional thermionic devices, providing greatly enhanced X-ray images with minimal X-ray dose. Although screen-printed CNT paste-emitters have been studied for a relatively long time, their field electron emissions have not been fully understood or optimally designed for specific electron source applications, because of the complexity arising from the intrinsic printing property, along with process reproducibility and device configurations. Here, we report an approach for the overall control of field electron emissions from multi-dot CNT paste-emitters, including electron-beam trajectories based on emitter dot size, dot array distribution, and triode configurations, using experiments and computational simulations. The crucial factors, such as the unit dot size of the CNT emitters and the aspect ratio of the triode structure, were successfully extracted, and can be used in designing and producing high-performance field-emitted electron source devices.
An in-depth study of the key factors affecting field emission characteristics was conducted using experiments and theoretical simulations with various geometries of triode-configured devices. The optimal design for a high-performance field emission device can be realized by manipulating of the key factors, such as the unit dot size of the CNT emitters and the geometrical ratio of the triode structure, which affects the trajectory and divergence of the field emitted electron beams. Display omitted
•An in-depth study for the key factors affecting field emission characteristics.•The overall control of field emissions from multi-dot CNT paste-emitters by experiments and computational simulations.•The effect of e-beam trajectories based on emitter dot size and macro-geometric factors.
Background It is rarely known whether antiplatelets increase the risk of bleeding after endoscopic submucosal dissection (ESD). Objective To evaluate the effect of antiplatelets on post-ESD bleeding. ...Design Retrospective study. Setting Single, tertiary-care referral center. Patients This study involved 1591 gastric neoplasms (815 adenomas and 776 early gastric cancers) in 1503 patients who had ESD between April 2005 and April 2010. Intervention ESD. Main Outcome Measurements Overt hematemesis/hematochezia, a drop of hemoglobin >2 g/dL from baseline, or requirement of endoscopic hemostasis, angiographic embolization, and/or transfusion. Results Of 1591 subjects, 274 took antiplatelets, among whom 102 discontinued them for 7 days or more before ESD. Post-ESD bleeding occurred in 94 subjects including 20 from the continuation group, 6 from the withdrawal group, and 68 from the no-antiplatelet group. In univariate analysis, antiplatelets, early gastric cancer (EGC), comorbidity, and specimen diameter were related to post-ESD bleeding. In multivariate analysis, EGC (odds ratio OR 1.839; 95% confidence interval CI, 1.168-2.896; P = .009), comorbidity (OR 2.246; 95% CI, 1.280-3.939; P = .005), and specimen diameter (OR 2.315; 95% CI, 1.282-4.180; P = .005) were independent risk factors of post-ESD bleeding, whereas antiplatelet usage was not (OR 1.596; 95% CI, 0.877-2.903; P = .126). In subgroup analysis, continuous antiplatelet usage was not found to be an independent risk factor of post-ESD bleeding in multivariate analysis (OR 2.027; P = .146). Among 102 subjects who discontinued antiplatelets, 1 developed an acute cerebral infarction (1.0%). Limitation A retrospective, single-center analysis. Conclusion In ESD for antiplatelet users, continuous administration was not found to have an independent significant association with bleeding.
BACKGROUND:Acute kidney injury (AKI) is a primary cause of morbidity and mortality after major abdominal surgery; however, little is known about the effect of anesthetics on the development of AKI ...after colorectal surgery. The objective of this study was to compare the effects of anesthesia with propofol and sevoflurane on postoperative AKI after colorectal surgery.
METHODS:For this study, we reviewed the electronic medical records of 4320 patients who underwent colorectal surgeries between January 2008 and December 2011. The influence of propofol and sevoflurane on the development of postoperative AKI and short-term outcomes was assessed by multivariable analysis, and the effect of the anesthetic agent on overall mortality was analyzed by a Cox proportional hazard model with propensity score matching method.
RESULTS:Overall, the incidence of AKI was 9.6% by Acute Kidney Injury Network (AKIN) criteria and 5.8% by risk, injury, failure, loss, and end-stage renal disease (RIFLE) criteria. The incidence of AKI incidence was greater in patients receiving sevoflurane than those receiving propofol (142 11.2% vs 272 8.9%, P = 0.02 by AKIN criteria, 94 7.4% vs 157 5.1%, P = 0.004 by RIFLE criteria). Multivariate logistic regression and propensity score matching results indicated that, when compared with propofol, sevoflurane anesthesia may be associated with the development of postoperative AKI (odds ratio OR, 1.29; P = 0.03; and OR, 1.44; P = 0.02 by AKIN and RIFLE criteria, and OR, 1.41; P = 0.04 by RIFLE criteria, respectively). We found no relationship between sevoflurane and overall mortality.
CONCLUSIONS:Compared with anesthesia with propofol, anesthesia with sevoflurane may be associated with a modest increase in the incidence of AKI when RIFLE but not AKIN criteria are used. Thus, the clinical meaning of these results is uncertain. Further work is needed to clarify the relevance of such an association.
Among abiotic stresses in plants, drought and chilling stresses reduce the supply of moisture to plant tissues, inhibit photosynthesis, and severely reduce plant growth and yield. Thus, the ...application of water stress-tolerant agents can be a useful strategy to maintain plant growth under abiotic stresses. This study assessed the effect of exogenous bio-based 2,3-butanediol (BDO) application on drought and chilling response in tomato and turfgrass, and expression levels of several plant signaling pathway-related gene transcripts. Bio-based 2,3-BDOs were formulated to levo-2,3-BDO 0.9% soluble concentrate (levo 0.9% SL) and meso-2,3-BDO 9% SL (meso 9% SL). Under drought and chilling stress conditions, the application of levo 0.9% SL in creeping bentgrass and meso 9% SL in tomato plants significantly reduced the deleterious effects of abiotic stresses. Interestingly, pretreatment with levo-2,3-BDO in creeping bentgrass and meso-2,3-BDO in tomato plants enhanced JA and SA signaling pathway-related gene transcript expression levels in different ways. In addition, all tomato plants treated with acibenzolar-
-methyl (as a positive control) withered completely under chilling stress, whereas 2,3-BDO-treated tomato plants exhibited excellent cold tolerance. According to our findings, bio-based 2,3-BDO isomers as sustainable water stress-tolerant agents, levo- and meso-2,3-BDOs, could enhance tolerance to drought and/or chilling stresses in various plants through somewhat different molecular activities without any side effects.
Ginsan, a polysaccharide extracted from Panax ginseng, has multiple immunomodulatory effects. In this study, we show that pretreatment of ginsan (25 μg/kg) protected mice from lethality induced by ...Staphylococcus aureus challenge. This survival benefit was associated with enhanced bacterial clearance from circulation, spleen and kidney. The phagocytic activity of macrophages treated with ginsan was significantly enhanced against S. aureus. However, the production of proinflammatory cytokines, such as TNF‐α, IL‐1β, IL‐6, IFN‐γ, IL‐12, and IL‐18, was markedly down‐regulated in ginsan‐treated mice compared with those of control‐infected mice. The expression of Toll‐like receptor (TLR) 2 and the adaptor molecule MyD88, which was greatly increased in septic macrophages, was significantly reduced by ginsan treatment in vitro. Similarly, the expression of phospho‐JNK1/2, phospho‐p38 MAPK, and NF‐κB was decreased in the same culture system. These results illustrate that the antiseptic activity of ginsan can be attributed to enhanced bacterial clearance, and reduced proinflammatory cytokines via the TLR signaling pathway.
Plumbagin (5-hydroxy-2-methyl-1,4-naphthaquinone) has displayed antitumor activity in vitro and in animal models; however, the underlying molecular mechanisms have not been fully explored. The aim of ...this study was to investigate the anticancer effects of plumbagin isolated from Nepenthes alata against MCF-7 breast cancer cells. We examined the cytotoxicity, cell cycle regulation, apoptotic cell death, and generation of intracellular reactive oxygen species (ROS) in MCF-7 cells. Plumbagin exhibited potent cytotoxicity in MCF-7 cells (wild-type p53) compared to that in SK-OV-3 (null-type) human epithelial ovarian cancer cells. Specifically, plumbagin upregulated the expression of p21CIP1/WAF1 in MCF-7 cells, causing cell cycle arrest in the G2/M phase through inhibition of cyclin B1 levels. Plumbagin also significantly increased the ratio of Bax/Bcl-2 and release of cytochrome c, resulting in apoptotic cell death in MCF-7 cells. Furthermore, plumbagin dramatically increased the intracellular ROS level, whereas pretreatment with the ROS scavenger N-acetyl cysteine protected against plumbagin-induced cytotoxicity, suggesting that ROS formation plays a pivotal role in antitumor activity in MCF-7 cells. In mice bearing MCF-7 cell xenografts, plumbagin significantly reduced tumor growth and weight without apparent side effects. We therefore concluded that plumbagin exerts anticancer activity against MCF-7 cells through the generation of intracellular ROS, resulting in the induction of apoptosis via a p53-dependent pathway. This study thus identifies a new anticancer mechanism of plumbagin against p53-dependent breast cancer cells and suggests a novel strategy for overcoming of breast cancer therapy.
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•Plumbagin, first isolated from N. alata, exhibits anticancer activity in human breast cancer MCF-7 cells.•ROS generation contributes to the cytotoxicity of plumbagin against MCF7 cells.•Plumbagin act as a lead molecule for new anticancer drug against breast cancer patients.
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