Water-redispersible and high-yield α-chitin nanocrystals isolated using electron-beam irradiation as adsorbents to remove heavy metals and dye.

An innovative approach to fabricate transparent and redispersible α-chitin nanocrystals (ChNCs) with high overall yields was developed in this work for eventual commercial use. The nanomanufacturing process included electron-beam irradiation (EBI) of chitin for oxidation and degradation in the dried state, high-pressure nanoscale homogenization via swelling, CO2 absorption, and spray-drying to obtain dehydrated products. The resulting EBI-disassociated chitins contained increased amounts of carboxylate (0.19-0.27 mmol g-1) and a negligible fraction of D-glucosamine moiety (from ca. 6.5 to <1.0%) with an intrinsic structure identical to α-chitin derived from shrimp shell prior to purification by conventional methods, such as deproteination. The resulting EBI-induced ChNC series exhibited nano-sized and rod-like morphology with tunable lengths averaging 608-259 nm, uniform widths of ca. 16-12 nm, a high isolation yield of max. 81%, and sufficient anionic surface charges, as zeta potentials of -32 to -34 mV indicate that it is homogenously water-dispersible and stable with background transparency. Unlike ChNC prepared by HCl-hydrolysis, the dehydrated particles of EBI-induced ChNCs were clearly redispersible in water and retained the characteristics of the original nanomaterials. We also tested the redispersible EBI-induced ChNCs as effective adsorbents. Their anionic groups interacted with cationic heavy metals (Cu2+ and Fe3+) and organic blue dye via electrostatic attraction, forming robust hydrogels, which were self-supporting after centrifugation. The EBI-induced ChNCs produced with low environmental impact in this work offer a promising choice of adsorbents for the removal of undesirable chemicals during wastewater treatment.

A Multicenter Retrospective Study on Clinical Characteristics and Outcome of Pyogenic Liver Abscess Focusing Multidrug-Resistant Organisms.

The emergence of multidrug-resistant organisms (MDROs) is a growing problem worldwide. However, little is known about the incidence, clinical features and outcomes of pyogenic liver abscesses (PLAs) caused by MDROs. A retrospective study of 833 patients with PLA admitted from 2008 to 2017 was performed. MDROs were found in 55 (6.6%) patients, and extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae was the most common causative microorganism. To evaluate the clinical features of and risk factors for MDRO-induced PLAs, propensity score matching (PSM) was performed in a 1:3 ratio (55 patients with MDROs and 165 patients without MDROs). After PSM, previous hepatobiliary procedure, preadmission exposure to antibiotics and elevated alkaline phosphatase levels were independent risk factors for MDRO-induced PLA. Sixteen patients (7.3%) died during hospitalization. Admission to intensive care unit (ICU), inadequate initial antibiotic treatment and use of inotropic agents were factors predictive of mortality. Although the presence of MDROs was not associated with in-hospital mortality, inadequate initial antibiotic treatment was prescribed to a large portion of the patients with MDRO-induced PLAs. We conclude that initial empirical antibiotic therapy for PLA should be based on the possibility of infection with MDROs, and close monitoring is necessary for patients with risk factors for in-hospital mortality.

Validation of the Friedewald formula for estimating low density lipoprotein cholesterol: the Korea National Health and Nutrition Examination Survey, 2009 to 2011.

BACKGROUND/AIMS: The aim of this study is to compare Friedewald-estimated and directly measured low density lipoprotein cholesterol (LDL-C) values and assess the concordance in guideline risk classification between the two methods. METHODS: The data were derived from the 2009 to 2011 Korea National Health and Nutrition Examination Survey. We included subjects with triglyceride (TG) levels < 400 mg/dL. Analysis was done for 6,454 subjects who had all lipid panels- total cholesterol, directly measured LDL-C, high density lipoprotein cholesterol (HDL-C), and TG. RESULTS: The subjects ranged in age from 10 to 87 years old. The mean age was 41.5 ± 17.3 years. For subjects with TG < 400 mg/dL, overall concordance in guideline risk classification was 79.1%. The Friedewald formula tended to underestimate LDL-C more at higher TG or lower HDL-C levels. Especially, the percent of subjects who were misclassified into a lower risk category was 31% when TG were 200 to 299 mg/dL; and 45.6% when TG were 300 to 399 mg/dL. A greater underestimation of LDL-C occurred at higher TG and lower Friedewald-estimated LDL-C levels. Of subjects with a Friedewald-estimated LDL-C < 70 mg/dL, 55.4% had a directly measured LDL-C ≥ 70 mg/dL when TG were 200 to 399 mg/dL. CONCLUSION: The Friedewald equation tends to underestimate LDL-C in highrisk subjects such as hypertriglyceridemia and hypo-HDL-cholesterolemia. For these individuals accurate assessment of LDL-C is crucial, and therefore additional evaluation is warranted.

Low-dose ionizing radiation alleviates Aß42-induced cell death via regulating AKT and p38 pathways in Drosophila Alzheimer's disease models.

Ionizing radiation is widely used in medicine and is valuable in both the diagnosis and treatment of many diseases. However, its health effects are ambiguous. Here, we report that low-dose ionizing radiation has beneficial effects in human amyloid-ß42 (Aß42)-expressing Drosophila Alzheimer's disease (AD) models. Ionizing radiation at a dose of 0.05 Gy suppressed AD-like phenotypes, including developmental defects and locomotive dysfunction, but did not alter the decreased survival rates and longevity of Aß42-expressing flies. The same dose of γ-irradiation reduced Aß42-induced cell death in Drosophila AD models through downregulation of head involution defective (hid), which encodes a protein that activates caspases. However, 4 Gy of γ-irradiation increased Aß42-induced cell death without modulating pro-apoptotic genes grim, reaper and hid The AKT signaling pathway, which was suppressed in Drosophila AD models, was activated by either 0.05 or 4 Gy γ-irradiation. Interestingly, p38 mitogen-activated protein-kinase (MAPK) activity was inhibited by exposure to 0.05 Gy γ-irradiation but enhanced by exposure to 4 Gy in Aß42-expressing flies. In addition, overexpression of phosphatase and tensin homolog (PTEN), a negative regulator of the AKT signaling pathway, or a null mutant of AKT strongly suppressed the beneficial effects of low-dose ionizing radiation in Aß42-expressing flies. These results indicate that low-dose ionizing radiation suppresses Aß42-induced cell death through regulation of the AKT and p38 MAPK signaling pathways, suggesting that low-dose ionizing radiation has hormetic effects on the pathogenesis of Aß42-associated AD.

Nardostachys jatamansi Ethanol Extract Ameliorates Aß42 Cytotoxicity.

The Nardostachys jatamansi DC (NJ) root has been used as a sedative or analgesic to treat neurological symptoms and pain in traditional Korean medicine. Here, we investigate the potential effects of NJ on Alzheimer's disease (AD) and reveal the molecular mechanism through which NJ exerts its effects. The neuroprotective effect of the NJ root ethanol extract against ß amyloid (Aß) toxicity was examined in vitro using a cell culture system and in vivo using a Drosophila AD model. The NJ extract and chlorogenic acid, a major component of NJ, inhibited Aß-induced cell death in SH-SY5Y cells. Moreover, the NJ extract rescued the neurological phenotypes of the Aß42-expressing flies (decreased survival and pupariation rate and a locomotor defect) and suppressed Aß42-induced cell death in the brain. We also found that NJ extract intake reduced glial cell number, reactive oxygen species level, extracellular-signal-regulated kinase (ERK) phosphorylation, and nitric oxide level in Aß42-expressing flies, without affecting Aß accumulation. These data suggest that the neuroprotective activity of NJ might be associated with its antioxidant and anti-inflammatory properties, as well as its inhibitory action against ERK signaling; thus, NJ is a promising medicinal plant for the development of AD treatment.

Rationale and Design for a Randomized Comparison of Efficacy and Safety between Aspirin and Clopidogrel in Atrial Fibrillation Patients with Low Stroke Risk: CESAC-AF trial.

BACKGROUND: Atrial fibrillation (AF) increases the risk of thromboembolic stroke. An oral anticoagulant should be administrated to prevent stroke in patients with moderate stroke risk (ie, CHA2DS2-VASc score>2). If the stroke risk is low (i.e. the score=1), however, antiplatelet agent such as aspirin is widely used. Aspirin can cause peptic ulcer disease (PUD) while its alternative, clopidogrel, theoretically does not. OBJECTIVE: To elucidate the efficacy and safety between aspirin and clopidogrel, a multicenter randomized controlled trial was designed in AF patients with low stroke risk. METHODS: According to sample size estimation based on previous literature, a total of 1560 AF patients with low stroke risk will be randomly assigned into 4 different groups dependent upon initial esophagogastroduodenoscopy (EGD) results: two mono-antiplatelet treatment groups with either aspirin 100mg or clopidogrel 75mg for 1year; two antiplatelet agent and proton pump inhibitor (PPI) combination groups. Follow-up EGD will be performed at 1year. RESULTS: The clinical follow-up will be performed for 1year after enrollment. The primary efficacy endpoint is to compare the annual stroke rate between aspirin and clopidogrel treatment groups. The primary safety endpoint is to compare the prevalence of drug-induced gastrointestinal (GI) and intracranial hemorrhage and upper-GI response including PUD based on EGD after 1year. CONCLUSIONS: This trial will determine whether clopidogrel is noninferior in stroke prevention and superior in reduction of GI events including PUD to aspirin in AF patients with low stroke risk. (ClinicalTrials.gov: NCT02960126).

Synthesis of Nano-Sized Silicon Oxide, Iron Oxide and Carbonates from Chrysotile Asbestos.

The objectives of this study were to investigate the physicochemical dissolution of chrysotile asbestos and to synthesize nano-sized materials and carbonate minerals from the asbestos via acid dissolution and pH changes. Chrysotile asbestos powder was dissolved in 3 different acids, HCl, HThe objectives of this study were to investigate the physicochemical dissolution of chrysotile asbestos and to synthesize nano-sized materials and carbonate minerals from the asbestos via acid dissolution and pH changes. Chrysotile asbestos powder was dissolved in 3 different acids, HCl, H2SO4, and HNO3, and the solutions were then titrated using NH4OH and reacted with CO2. The residual material and precipitates were examined with XRD and TEM-EDS. ICP-AES analysis was also used to investigate the chemical makeup of the solution. The concentration of Mg in the solution was about 1,280 mg/L. The chrysotile became noncrystalline silica after acid treatment (pH = 0). At pH 8.6 and 9.5, the precipitates were amorphous iron oxide and nesquehonite [Mg(HCO3)(OH)·2(H2O)] after reaction with CO2. The particle size of the precipitates ranged from 2 to 500 nm. These results indicate that dissolution of chrysotile asbestos using HCl, H2SO4, and HNO3 can chemically alter chrysotile fibers. Also, the dissolved materials can be used as precursors for other materials such as silica, iron oxide, and carbonates. This process may be useful for the synthesis of silica and iron oxides and for mineral carbonation for carbon sequestration. SO4, and HNO3, and the solutions were then titrated using NH4OH and reacted with CO2. The residual material and precipitates were examined with XRD and TEM-EDS. ICP-AES analysis was also used to investigate the chemical makeup of the solution. The concentration of Mg in the solution was about 1,280 mg/L. The chrysotile became noncrystalline silica after acid treatment (pH = 0). At pH 8.6 and 9.5, the precipitates were amorphous iron oxide and nesquehonite [Mg(HCO3)(OH)·2(H2O)] after reaction with CO2. The particle size of the precipitates ranged from 2 to 500 nm. These results indicate that dissolution of chrysotile asbestos using HCl, H2SO4, and HNO3 can chemically alter chrysotile fibers. Also, the dissolved materials can be used as precursors for other materials such as silica, iron oxide, and carbonates. This process may be useful for the synthesis of silica and iron oxides and for mineral carbonation for carbon sequestration.

Coriandrum sativum Suppresses Aß42-Induced ROS Increases, Glial Cell Proliferation, and ERK Activation.

Alzheimer's disease (AD), the most common neurodegenerative disease, has a complex and widespread pathology that is characterized by the accumulation of amyloid [Formula: see text]-peptide (A[Formula: see text]) in the brain and various cellular abnormalities, including increased oxidative damage, an amplified inflammatory response, and altered mitogen-activated protein kinase signaling. Based on the complex etiology of AD, traditional medicinal plants with multiple effective components are alternative treatments for patients with AD. In the present study, we investigated the neuroprotective effects of an ethanol extract of Coriandrum sativum (C. sativum) leaves on A[Formula: see text] cytotoxicity and examined the molecular mechanisms underlying the beneficial effects. Although recent studies have shown the benefits of the inhalation of C. sativum oil in an animal model of AD, the detailed molecular mechanisms by which C. sativum exerts its neuroprotective effects are unclear. Here, we found that treatment with C. sativum extract increased the survival of both A[Formula: see text]-treated mammalian cells and [Formula: see text]42-expressing flies. Moreover, C. sativum extract intake suppressed [Formula: see text]-induced cell death in the larval imaginal disc and brain without affecting A[Formula: see text]42 expression and accumulation. Interestingly, the increases in reactive oxygen species levels and glial cell number in AD model flies were reduced by C. sativum extract intake. Additionally, C. sativum extract inhibited the epidermal growth factor receptor- and A[Formula: see text]-induced phosphorylation of extracellular signal-regulated kinase (ERK). The constitutively active form of ERK abolished the protective function of C. sativum extract against the [Formula: see text]-induced eye defect phenotype in Drosophila. Taken together, these results suggest that C. sativum leaves have antioxidant, anti-inflammatory, and ERK signaling inhibitory properties that are beneficial for patients with AD.

A huge saccular aortic aneurysm compressing right coronary artery 7 years after aortic valve replacement due to bicuspid aortic valve insufficiency: A rare case report.

BACKGROUND: In a patient underwent aortic valve replacement (AVR) due to bicuspid aortic valve (BAV) insufficiency without marked dilation of ascending aorta, the development of delayed-typed aneurysmal complication of ascending aorta has been often reported because the dilated aorta tends to grow insidiously with age. CASE SUMMARY: A 58-year-old man who underwent AVR with mechanical valve due to severe aortic regurgitation secondary to BAV 7 years previously presented with exertional chest discomfort for 1 year. An echocardiography showed a well-functioning mechanical aortic valve without any significant abnormal findings. Cardiac multidetector computed tomography (MDCT) revealed a huge saccular aortic root aneurysm (79.7 mm × 72.8 mm in size) compressing the proximal right coronary artery resulting in ∼90% eccentric diffuse luminal narrowing. The patient subsequently underwent open-heart surgery with resection of the ascending aortic aneurysmal sac and consecutive ascending aorta and hemi-arch replacement using a graft. CONCLUSION: After successful AVR in the patient with BAV insufficiency and mildly dilated ascending aorta, a regular aortic imaging such as cardiac MDCT with aortography would be helpful to monitor the morphology and size of ascending aorta and related complications to guide future management.

The calcineurin inhibitor Sarah (Nebula) exacerbates Aß42 phenotypes in a Drosophila model of Alzheimer's disease.

Expression of the Down syndrome critical region 1 (DSCR1) protein, an inhibitor of the Ca(2+)-dependent phosphatase calcineurin, is elevated in the brains of individuals with Down syndrome (DS) or Alzheimer's disease (AD). Although increased levels of DSCR1 were often observed to be deleterious to neuronal health, its beneficial effects against AD neuropathology have also been reported, and the roles of DSCR1 on the pathogenesis of AD remain controversial. Here, we investigated the role of sarah (sra; also known as nebula), a Drosophila DSCR1 ortholog, in amyloid-ß42 (Aß42)-induced neurological phenotypes in Drosophila. We detected sra expression in the mushroom bodies of the fly brain, which are a center for learning and memory in flies. Moreover, similar to humans with AD, Aß42-expressing flies showed increased Sra levels in the brain, demonstrating that the expression pattern of DSCR1 with regard to AD pathogenesis is conserved in Drosophila. Interestingly, overexpression of sra using the UAS-GAL4 system exacerbated the rough-eye phenotype, decreased survival rates and increased neuronal cell death in Aß42-expressing flies, without modulating Aß42 expression. Moreover, neuronal overexpression of sra in combination with Aß42 dramatically reduced both locomotor activity and the adult lifespan of flies, whereas flies with overexpression of sra alone showed normal climbing ability, albeit with a slightly reduced lifespan. Similarly, treatment with chemical inhibitors of calcineurin, such as FK506 and cyclosporin A, or knockdown of calcineurin expression by RNA interference (RNAi), exacerbated the Aß42-induced rough-eye phenotype. Furthermore, sra-overexpressing flies displayed significantly decreased mitochondrial DNA and ATP levels, as well as increased susceptibility to oxidative stress compared to that of control flies. Taken together, our results demonstrating that sra overexpression augments Aß42 cytotoxicity in Drosophila suggest that DSCR1 upregulation or calcineurin downregulation in the brain might exacerbate Aß42-associated neuropathogenesis in AD or DS.

Structural Origin of the Band Gap Anomaly of Quaternary Alloy Cd(x)Zn(1-x)S(y)Se(1-y) Nanowires, Nanobelts, and Nanosheets in the Visible Spectrum.

Single-crystalline alloy II-VI semiconductor nanostructures have been used as functional materials to propel photonic and optoelectronic device performance in a broad range of the visible spectrum. Their functionality depends on the stable modulation of the direct band gap (Eg), which can be finely tuned by controlling the properties of alloy composition, crystallinity, and morphology. We report on the structural correlation of the optical band gap anomaly of quaternary alloy CdxZn1-xSySe1-y single-crystalline nanostructures that exhibit different morphologies, such as nanowires (NWs), nanobelts (NBs), and nanosheets (NSs), and cover a wide range of the visible spectrum (Eg = 1.96-2.88 eV). Using pulsed laser deposition, the nanostructures evolve from NWs via NBs to NSs with decreasing growth temperature. The effects of the growth temperature are also reflected in the systematic variation of the composition. The alloy nanostructures firmly maintain single crystallinity of the hexagonal wurtzite and the nanoscale morphology, with no distortion of lattice parameters, satisfying the virtual crystal model. For the optical properties, however, we observed distinct structure-dependent band gap anomalies: the disappearance of bowing for NWs and maximum and slightly reduced bowing for NBs and NSs, respectively. We tried to uncover the underlying mechanism that bridges the structural properties and the optical anomaly using an empirical pseudopotential model calculation of electronic band structures. From the calculations, we found that the optical bowings in NBs and NSs were due to residual strain, by which they are also distinguishable from each other: large for NBs and small for NSs. To explain the origin of the residual strain, we suggest a semiempirical model that considers intrinsic atomic disorder, resulting from the bond length mismatch, combined with the strain relaxation factor as a function of the width-to-thickness ratio of the NBs or NSs. The model agreed well with the observed optical bowing of the alloy nanostructures in which a mechanism for the maximum bowing for NBs is explained. The present systematic study on the structural-optical properties correlation opens a new perspective to understand the morphology- and composition-dependent unique optical properties of II-VI alloy nanostructures as well as a comprehensive strategy to design a facile band gap modulation method of preparing photoconverting and photodetecting materials.