High Electrochemical Performance Silicon Thin-Film Free-Standing Electrodes Based on Buckypaper for Flexible Lithium-Ion Batteries

Recently, applications for lithium-ion batteries (LIBs) have expanded to include electric vehicles and electric energy storage systems, extending beyond power sources for portable electronic devices. The power sources of these flexible electronic devices require the creation of thin, light, and flexible power supply devices such as flexile electrolytes/insulators, electrode materials, current collectors, and batteries that play an important role in packaging. Demand will require the progress of modern electrode materials with high capacity, rate capability, cycle stability, electrical conductivity, and mechanical flexibility for the time to come. The integration of high electrical conductivity and flexible buckypaper (oxidized Multi-walled carbon nanotubes (MWCNTs) film) and high theoretical capacity silicon materials are effective for obtaining superior high-energy-density and flexible electrode materials. Therefore, this study focuses on improving the high-capacity, capability-cycling stability of the thin-film Si buckypaper free-standing electrodes for lightweight and flexible energy-supply devices. First, buckypaper (oxidized MWCNTs) was prepared by assembling a free stand-alone electrode, and electrical conductivity tests confirmed that the buckypaper has sufficient electrical conductivity (10⁻⁴(S m⁻¹) in LIBs) to operate simultaneously with a current collector. Subsequently, silicon was deposited on the buckypaper via magnetron sputtering. Next, the thin-film Si buckypaper freestanding electrodes were heat-treated at 600 °C in a vacuum, which improved their electrochemical performance significantly. Electrochemical results demonstrated that the electrode capacity can be increased by 27/26 and 95/93 μAh in unheated and heated buckypaper current collectors, respectively. The measured discharge/charge capacities of the USi_HBP electrode were 108/106 μAh after 100 cycles, corresponding to a Coulombic efficiency of 98.1%, whereas the HSi_HBP electrode indicated a discharge/charge capacity of 193/192 μAh at the 100th cycle, corresponding to a capacity retention of 99.5%. In particular, the HSi_HBP electrode can decrease the capacity by less than 1.5% compared with the value of the first cycle after 100 cycles, demonstrating excellent electrochemical stability.     

Sexually transmitted infections among pregnant women attending antenatal clinics in Mongolia: potential impact on the Mongolian HIV epidemic

We conducted Mongolia's first nation-wide cross-sectional survey of sexually transmitted infections (STIs) among pregnant women attending prenatal care. Among our 2000 participants, 386 (19.3%) were infected with Chlamydia trachomatis, 133 (6.7%) with Trichomonas vaginalis, 121 (6.1%) with Neisseria gonorrhoeae, and 128 (6.4%) were seropositive for Treponemal antibodies. None of our participants were seropositive for HIV infection. Additionally, 605 (30.3%) of the women had at least one STI, 133 (6.7%) had a double infection, and 15 (0.8%) had a triple infection. Our results suggest that STIs are a serious problem in Mongolia. Pregnant women represent a lower-risk general population; these high STI rates suggest that at this nascent stage, the identification, treatment, and prevention of STIs as risk factors for HIV transmission are crucial in the prevention of the emerging Mongolian HIV epidemic.     

Identification of Sleep Apnea Severity Based on Deep Learning from a Short-term Normal ECG

BackgroundThis paper proposes a novel method for automatically identifying sleep apnea (SA) severity based on deep learning from a short-term normal electrocardiography (ECG) signal.MethodsA convolutional neural network (CNN) was used as an identification model and implemented using a one-dimensional convolutional, pooling, and fully connected layer. An optimal architecture is incorporated into the CNN model for the precise identification of SA severity. A total of 144 subjects were studied. The nocturnal single-lead ECG signal was collected, and the short-term normal ECG was extracted from them. The short-term normal ECG was segmented for a duration of 30 seconds and divided into two datasets for training and evaluation. The training set consists of 82,952 segments (66,360 training set, 16,592 validation set) from 117 subjects, while the test set has 20,738 segments from 27 subjects.ResultsF1-score of 98.0% was obtained from the test set. Mild and moderate SA can be identified with an accuracy of 99.0%.ConclusionThe results showed the possibility of automatically identifying SA severity based on a short-term normal ECG signal.     

Inducible NOS inhibition, eicosapentaenoic acid supplementation, and angiotensin II-induced renal damage

BACKGROUND: Cytochrome P450(CYP)-dependent hydroxylation and epoxygenation metabolites of arachidonic acid (AA) influence renal vascular tone, salt excretion, and inflammation. Transgenic rats over expressing both human renin and angiotensinogen genes (dTGR) feature angiotensin II (Ang II)-induced organ damage, increased expression of inducible nitric oxide synthase (iNOS), decreased AA hydroxylation, and epoxygenation. As nitric oxide production via iNOS can inhibit CYP AA metabolism, we tested the hypothesis that by blocking iNOS or by supplementing eicosapentanoic acid (EPA), which can serve as an alternative CYP substrate, Ang II-induced vasculopathy could be ameliorated. METHODS: We treated dTGR with the iNOS inhibitor L-N(6)-(1-iminoethyl) lysine (L-NIL), EPA, and the combination of both treatments from week 4 to 7. RESULTS: Immunohistochemistry showed that L-NIL and EPA reduced glomerular iNOS toward control levels. L-NIL-treated dTGR showed cardiac hypertrophy and albuminuria similar to untreated dTGR. EPA and the combination of EPA + L-NIL, ameliorated organ damage without lowering blood pressure. EPA and EPA + L-NIL reduced cardiac hypertrophy, albuminuria, renal fibronectin expression, and infiltration of monocytes/macrophages, compared to L-NIL and untreated dTGR. Reactive oxygen species were detected in glomeruli of untreated and L-NIL-treated dTGR, but was reduced in the EPA groups. EPA treatment reduced activator protein-1 (AP-1) activation and partially inhibited nuclear factor-kappaB (NF-kappaB) activity in kidneys of dTGR. CONCLUSION: These results demonstrate that iNOS inhibition does not protect against Ang II-induced end-organ damage, while EPA treatment does. Our electromobility shift assay experiments revealed that EPA protection may involve inhibition of AP-1- and NF-kappaB-dependent pathways.     

Protective role of CXC receptor 4/CXC ligand 12 unveils the importance of neutrophils in atherosclerosis

The CXC ligand (CXCL)12/CXC receptor (CXCR)4 chemokine-receptor axis controls hematopoiesis, organ development, and angiogenesis, but its role in the inflammatory pathogenesis of atherosclerosis is unknown. Here we show that interference with Cxcl12/Cxcr4 by a small-molecule antagonist, genetic Cxcr4 deficiency, or lentiviral transduction with Cxcr4 degrakine in bone marrow chimeras aggravated diet-induced atherosclerosis in apolipoprotein E-deficient (Apoe-/-) or LDL receptor-deficient (Ldlr-/-) mice. Chronic blockade of Cxcr4 caused leukocytosis and an expansion of neutrophils and increased neutrophil content in plaques, associated with apoptosis and a proinflammatory phenotype. Whereas circulating neutrophils were recruited to atherosclerotic lesions, depletion of neutrophils reduced plaque formation and prevented its exacerbation after blocking Cxcr4. Disrupting Cxcl12/Cxcr4 thus promotes lesion formation through deranged neutrophil homeostasis, indicating that Cxcl12/Cxcr4 controls the important contribution of neutrophils to atherogenesis in mice.     

Characterization of methicillin-resistant Staphylococcus aureus from Ulaanbaatar, Mongolia

In order to expand current knowledge of the types of methicillin-resistant Staphylococcus aureus (MRSA) strains circulating in central Asia, six MRSA strains collected from hospitals in Ulaanbaatar, Mongolia during 2000–2002 were examined. Three strains possessed a staphylococcal cassette chromosome mec (SCCmec) element of type IV c, were sequence type (ST) 154 according to multilocus sequence typing (MLST), and contained lukS–lukF (Panton–Valentine leukocidin). Another three strains contained a SCCmec element of type III and were MLST type ST 239. Using automated ribotyping, the six MRSA strains were divided into four different EcoRI ribotypes, and two groups of isolates were distinguished by means of SmaI-macrorestriction patterns. In comparison to other countries, the incidence of MRSA in Mongolia is low.     

Aldosterone, mineralocorticoid receptors, and vascular inflammation

PURPOSE OF REVIEW: Aldosterone and its mineralocorticoid receptor represent an ancient signaling system. Indeed, the mineralocorticoid receptor is older than its agonist. Both have probably served various functions through the eons and salt preservation may be relatively recent. A large body of evidence suggests that aldosterone conducts signaling in vascular cells and contributes substantially to vascular remodeling and target organ damage. A blood pressure and salt balance-independent effect was first observed in two large heart failure trials. RECENT FINDINGS: Mineralocorticoid receptor blockade has now been shown to reduce proteinuria even in the face of angiotensin converting enzyme inhibition and AT1 receptor blockade. Mineralocorticoid receptor blockade effectively reduces target organ damage in every hypertensive model tested, irrespective of circulating renin and aldosterone levels. Protection is also observed in nonhypertensive diabetic and hyperlipidemic models. Signaling in vascular cells involves primarily the mitogen activated protein kinase pathway with participation of the epidermal growth factor receptor. Novel signaling molecules have been shown to participate in aldosterone-mediated actions including the murine double-minute type 2 protein that participates in antiapoptotic and proliferative effects. Clinically, mutations in the mineralocorticoid receptor have shed additional light on its importance. SUMMARY: A resurgence of interest in aldosterone reflects its importance and clinical relevance for vascular remodeling and target organ damage.     

Agonistic autoantibodies to the AT1 receptor in a transgenic rat model of preeclampsia

We used rats transgenic for the human angiotensinogen (hAogen) gene and the human renin (hRen) gene and crossed the strains to produce a model of preeclampsia in the dams. The female (n=9) hAogen x male hRen cross had severe (telemetry-measured) hypertension and albuminuria, which developed during the last trimester of pregnancy and subsided after delivery. The converse cross (n=9) and control (n=9) SD rats did not. We demonstrated that the female hAogen x male hRen cross had agonistic antibodies capable of activating the angiotensin (Ang) II AT1 receptor (AT1R-AA) and defined the epitope on the receptor's second extracellular loop. The phenomenon also occurs in humans with preeclampsia. The rats displayed renal histology reminiscent of preeclampsia, including fibrin deposition confined to the glomeruli. The complement system was activated in glomeruli and IgG deposits were present that may represent AT1R-AA. Finally, we observed an atherosis-like lesion in the spiral arteries of the placental bed, which we called placental-bed arteriolosclerosis. Our model may be relevant to preeclampsia in humans.