Resistance mutations A2058G and A2059G, within the 23S rRNA gene of Treponema pallidum, have been reported to cause treatment failures in patients receiving azithromycin for syphilis. Genotyping of ...T. pallidum strains sequentially isolated from patients with recurrent syphilis is rarely performed. From September 2009 to August 2013, we collected 658 clinical specimens from 375 patients who presented with syphilis for genotyping to examine the number of 60-bp repeats in the acidic repeat protein (arp) gene, T. pallidum repeat (tpr) polymorphism, and tp0548 gene, and to detect A2058G and A2059G point mutations by restriction fragment length polymorphism. Treponemal DNA was identified in 45.2% (n = 298) of the specimens that were collected from 216 (57.6%) patients; 268 (40.7%) specimens tested positive for the 23S rRNA gene, and were examined for macrolide resistance. Two isolates (0.7%) harboured the A2058G mutation, and no A2059G mutation was identified. A total of 14 strains of T. pallidum were identified, with 14f/f (57.5%) and 14b/c (10.0%) being the two predominant strains. Forty patients who presented with recurrent episodes of syphilis had T. pallidum DNA identified from the initial and subsequent episodes, with five cases showing strain discrepancies. One patient had two strains identified from different clinical specimens collected in the same episode. Our findings show that 14f/f is the most common T. pallidum strain in Taiwan, where the prevalence of T. pallidum strains that show A2058G or A2059G mutation remains low. Different genotypes of T. pallidum can be identified in patients with recurrent episodes of syphilis.
Acute stroke is the third leading cause of death in Taiwan. Although statin therapy is widely recommended for stroke prevention, little is known about the epidemiology of statin therapy after acute ...ischemic stroke (AIS) in Taiwan. To investigate the effects of statin therapy on recurrent stroke, intracranial hemorrhage (ICH), coronary artery disease (CAD), cost of hospitalization and mortality, we conducted a nationwide population-based epidemiologic study.
Cases of AIS were identified from the annual hospitalization discharge diagnoses of the National Health Insurance Research Database with the corresponding International Classification of Diseases, ninth revision codes from January 2001 to December 2010. We divided the AIS patients into three groups: non-statin, pre-stroke statin and post-stroke statin.
A total of 422 671 patients with AIS (including 365 419 cases in the non-statin group, 22 716 cases in the pre-stroke statin group and 34 536 cases in the post-stroke statin group) were identified. When compared to the non-statin group, both statin groups had a lower recurrent stroke risk pre-stroke statin: odds ratio (OR) = 0.84; 95% confidence interval (CI) = 0.82-0.87; P < 0.0001; post-stroke statin: OR = 0.89; 95% CI = 0.86-0.91; P < 0.0001, lower ICH risk (pre-statin: OR = 0.75; 95% CI = 0.69-0.82; P < 0.0001; post-stroke statin: OR = 0.75; 95% CI = 0.71-0.81; P < 0.0001), and a lower mortality rate (pre-stroke statin: OR = 0.56; 95% CI = 0.53-0.59; P < 0.0001; post-stroke statin: OR = 0.51; 95% CI = 0.48-0.53; P < 0.0001). In terms of CAD, only the post-statin group had a lower risk (OR = 0.81; 95% CI = 0.79-0.84; P < 0.0001) than the non-statin group. The post-statin group had the lowest 1-year medical costs after index discharge among the three groups.
Statin therapy reduced the risks of recurrent stroke, CAD, ICH and the first year mortality in patients after AIS. Treatment with statin therapy after AIS is a cost-effective strategy in Taiwan.
Caregivers play a major role in providing care for patients with Alzheimer's disease (AD) and are themselves at higher risk of health comorbidities.
To address the impact of neuropsychiatric symptoms ...of patients in different stages of AD on their caregivers' burden.
This prospective study enrolled 260 AD patients with clinical dementia rating (CDR) of 0.5, 1 and 2 at a tertiary medical center.
All patients were tested using the mini-mental state examination (MMSE), the cognitive abilities screening instrument (CASI), the neuropsychiatric inventory (NPI) and the CDR scale. Data regarding therapeutic outcomes of anti-Alzheimer's drugs were also collected. Caregivers were tested using NPI.
The mean follow-up interval was 25.0 ± 12.2 months, and two patients died during follow-up. NPI-burden was positively correlated with NPI-sum ( r = 0.822, P < 0.001) but negatively correlated with years of education ( r = -0.140, P = 0.024), CASI score ( r = -0.259, P < 0.001) and MMSE score ( r = -0.262, P <0.001). Multiple linear regression analysis showed that only NPI-sum was independently associated with mean NPI-burden. Both higher mean CASI and MMSE scores had better therapeutic outcome of anti-Alzheimer's drugs ( P = 0.001 and P = 0.005, respectively).
The severity of neuropsychiatric symptoms in patients with AD was positively associated with caregiver's stress, and patients with better cognitive functions, under treatment with anti-Alzheimer's drugs, had better therapeutic outcomes. To reduce the impact of neuropsychiatric symptoms, it is crucial to detect dementia in its early phases and provide early intervention with anti-Alzheimer's drugs, which might help decrease the caregiver burden, thereby improving their quality of life.
Mechanical Writing of Ferroelectric Polarization Lu, H.; Bark, C.-W.; de los Ojos, D. Esque ...
Science (American Association for the Advancement of Science),
04/2012, Letnik:
336, Številka:
6077
Journal Article
Recenzirano
Odprti dostop
Ferroelectric materials are characterized by a permanent electric dipole that can be reversed through the application of an external voltage, but a strong intrinsic coupling between polarization and ...deformation also causes all ferroelectrics to be piezoelectric, leading to applications in sensors and high-displacement actuators. A less explored property is flexoelectricity, the coupling between polarization and a strain gradient. We demonstrate that the stress gradient generated by the tip of an atomic force microscope can mechanically switch the polarization in the nanoscale volume of a ferroelectric film. Pure mechanical force can therefore be used as a dynamic tool for polarization control and may enable applications in which memory bits are written mechanically and read electrically.
Phytochemicals have been used as potential chemopreventive or chemotherapeutic agents. However, there are data suggesting a mutagenic effect of some phytochemicals. We hypothesized that safrole would ...have anticancer effects on human oral squamous cell carcinoma HSC-3 cells. Safrole decreased the percentage of viable HSC-3 cells via induction of apoptosis by an increased level of cytosolic Ca2+ and a reduction in the mitochondrial membrane potential (ΔΨ
m
). Changes in the membrane potential were associated with changes in the Bax, release of cytochrome c from mitochondria, and activation of downstream caspases-9 and -3, resulting in apoptotic cell death. In vivo studies also showed that safrole reduced the size and volume of an HSC-3 solid tumor on a xenograft athymic nu/nu mouse model. Western blotting and flow cytometric analysis studies confirmed that safrole-mediated apoptotic cell death of HSC-3 cells is regulated by cytosolic Ca2+ and by mitochondria- and Fas-dependent pathways.
Ferroelectric Tunnel Memristor Kim, D. J; Lu, H; Ryu, S ...
Nano letters,
11/2012, Letnik:
12, Številka:
11
Journal Article
Recenzirano
Strong interest in resistive switching phenomena is driven by a possibility to develop electronic devices with novel functional properties not available in conventional systems. Bistable resistive ...devices are characterized by two resistance states that can be switched by an external voltage. Recently, memristorselectric circuit elements with continuously tunable resistive behaviorhave emerged as a new paradigm for nonvolatile memories and adaptive electronic circuit elements. Employment of memristors can radically enhance the computational power and energy efficiency of electronic systems. Most of the existing memristor prototypes involve transition metal oxide resistive layers where conductive filaments formation and/or the interface contact resistance control the memristive behavior. In this paper, we demonstrate a new type of memristor that is based on a ferroelectric tunnel junction, where the tunneling conductance can be tuned in an analogous manner by several orders of magnitude by both the amplitude and the duration of the applied voltage. The ferroelectric tunnel memristors exhibit a reversible hysteretic nonvolatile resistive switching with a resistance ratio of up to 105 % at room temperature. The observed memristive behavior is attributed to the field-induced charge redistribution at the ferroelectric/electrode interface, resulting in the modulation of the interface barrier height.
An innovative wet‐treatment with Na2S transforms two indium metal‐organic frameworks (MOFs) into a series of porous inorganic sorbents. These MOF‐templated materials display remarkable affinity for ...heavy metals with saturation occurring in less than 1 h. The saturation capacity for Hg(II) exceeds 2 g g‐1, more than doubling the best thiol‐functionalized sorbents in the literature.
This study presents graphene oxide (GO)-laminated Nafion 115 as a proton exchange membrane for a direct methanol fuel cell (DMFC). Compared to a GO-dispersed polymer composite membrane, a ...GO-laminated proton-conducting membrane is advantageous for DMFC operating at higher methanol feed concentrations. The novel laminate membrane consists of highly ordered GO paper with parallel orientation prepared by using a vacuum filtration method. This dual-layer membrane is fabricated by laminating the Nafion 115 membrane with a highly orientated GO paper through transfer printing followed by hot-pressing. Scanning electron microcopy (SEM) shows that the GO paper measuring approximately 1.0 μm thick (i.e., corresponding to 1.5 wt%) adhered well to the base membrane. The methanol permeability of the GO-laminated membrane is approximately 70% lower than that of Nafion 115 at an expense of a 22% decrease in proton conductivity. The proposed membrane has a 40% higher selectivity (i.e. ratio of proton conductivity to methanol permeability) than Nafion 115. The GO-laminated Nafion membrane is far superior to the pristine Nafion membrane in DMFC performance when operating at an 8 M methanol feed concentration.
•A GO-laminated Nafion membrane for DMFC is originally proposed.•The parallel orientation of the GO paper can effectively block methanol crossover.•The novel membrane shows its superiority in DMFC at higher methanol feed concentrations.
Nucleolin (NCL) participates in DNA transcription, ribosomal biogenesis and the regulation of RNA stability. However, the contribution of NCL to tumor development is still not clear. Herein, we found ...that NCL expression correlated with poor prognosis in lung cancer patients. Overexpressed NCL was predominantly cleaved to C-terminal truncated NCL (TNCL). In lung cancer formation, activation of the epidermal growth factor receptor pathway induced NCL expression, and also the expression of matrix metalloproteinase (MMP) 7, which then cleaved NCL at Asp255 to generate TNCL of 55 kDa. TNCL increased the expression of several oncogenes, including MMP9, anaplastic lymphoma kinase (ALK), HIF1a and CBLB, and decreased the expression of tumor suppressors including BRD4, PCM1, TFG and KLF6 by modulating mRNA stability through binding to the 3'-untranslated regions of their transcripts, thus ultimately enhancing metastasis activity. In conclusion, this study identified a novel role of the cleavage form of NCL generated by MMP7 in stabilizing MMP9 mRNA. We also provide a new insight that MMP7 not only cleaves the extracellular matrix to promote tumor invasion but also cleaves NCL, which augment oncogenesis. Blocking NCL cleavage may provide a useful new strategy for lung cancer therapy.
Within the chiral unitary approach and with the constraints of heavy quark spin symmetry, we study the coupled channel interactions of D (*) Σc (*) channels, close to whose thresholds three ...pentaquarklike P c states have been reported by the LHCb Collaboration. In the present work, we take into account the contributions of pion exchanges via box diagrams to the interaction potentials, and therefore lift the degeneracy in the masses of D ∗ Σc (*) spin multiplets. Fitting the J/ψp invariant mass distributions in the Λ0b → J/ψK − p decay, we find that the LHCb pentaquark states cannot be reproduced in the direct J/ψp production in the Λ0b decay, and can only be indirectly produced in the final state interactions of the Λ0b decay products, D (*) Σc (*), which further supports the nature of these states as D (*) Σc molecules. Based on the fit results obtained, we study the partial decay widths/branching ratios to the other decay channels, D ∗ Λc, D Λc, and ηcN, and the corresponding invariant mass distributions. The resonances with JP = 1/2 −, Pc (4312), Pc (4440) and the one of D ∗ Σ∗c around 4500 MeV, have large partial decay width into ηcN, and thus can be easily seen in the ηcN invariant mass distributions. By contrast, the states with JP = 3/2 −, Pc (4457), the (predicted) narrow Pc (4380), and the bound state of ¯ D∗Σ∗c with a mass of about 4520 MeV do not decay into ηcN. Therefore, the ηcN channel should be studied in the future to provide further insights into the nature of these states, especially that of Pc (4440) and Pc (4457) .
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