14 research outputs found
Understanding the Intrinsic Water Wettability of Molybdenum Disulfide (MoS<sub>2</sub>)
2D
semiconductors allow for unique and ultrasensitive devices to
be fabricated for applications ranging from clinical diagnosis instruments
to low-energy light-emitting diodes (LEDs). Graphene has championed
research in this field since it was first fabricated; however, its
zero bandgap creates many challenges. Transition metal dichalcogenides
(TMDCs), e.g., MoS<sub>2</sub>, have a direct bandgap which alleviates
the challenge of creating a bandgap in graphene-based devices. Water
wettability of MoS<sub>2</sub> is critical to device fabrication/performance
and MoS<sub>2</sub> has been believed to be hydrophobic. Herein, we
report that water contact angle (WCA) of freshly exfoliated MoS<sub>2</sub> shows temporal evolution with an intrinsic WCA of 69.0 ±
3.8° that increases to 89.0 ± 3.1° after 1 day exposure
to ambient air. ATR-FTIR and ellipsometry show that the fresh, intrinsically
mildly hydrophilic MoS<sub>2</sub> surface adsorbs hydrocarbons from
ambient air and thus becomes hydrophobic
Effect of π–π+ Stacking on the Layering of Ionic Liquids Confined to an Amorphous Carbon Surface
In
the current paper, AFM studies were conducted on nanometer-thick
ionic liquids (ILs) confined to an amorphous carbon (AC) surface,
which is critical to the design of the next-generation media lubricant
for hard disk drives (HDDs). The results indicated that the existence
of the delocalized ring in the cation is critical to layering of ILs.
Extended layering was observed only when there is imidazolium ring
in the cation. When the imidazolium ring is replaced by an aliphatic
moiety, “drop-on-layer” (dewetting) structure was observed.
On the basis of the experimental results, we proposed that π–π+
stacking between sp<sup>2</sup> carbon in the AC and the imidazolium
cation in the ILs is the key to the extended layering of ILs at the
ILs/AC interface
Multifunctional Superamphiphobic Cotton Fabrics with Highly Efficient Flame Retardancy, Self-Cleaning, and Electromagnetic Interference Shielding
Here,
a facile method is reported to prepare multifunctional cotton
fabrics with high flame retardancy, high electrical conductivity,
superamphiphobicity, and high electromagnetic shielding. The cotton
fabric surface was first modified with phytic acid (PA), which promoted
dehydration and carbonization of cellulose to increase flame retardancy
in the process of pyrolysis. Tannic acid (TA) and 3-aminopropyltriethoxysilane
(APTES) coating with nanospheres as interlayers created hierarchical
roughness that facilitated the construction of superamphiphobic surfaces
and provided adhesion sites for silver nanoparticles. In addition,
the TA-APTES coating improved flame retardancy because the APTES-containing
silicon could form silicon carbon layers to isolate heat and oxygen.
Subsequently, the surface energy of the composite cotton fabric was
reduced by fluorine-containing molecules. The prepared composite cotton
fabric exhibited excellent superamphiphobicity with contact angles
of 160.3 and 152° for water and olive oil, respectively. The
conductivity and EMI shielding efficiency of the prepared composite
cotton fabric reached 629.93 S/cm and 76 dB, respectively. Importantly,
the composite cotton fabric maintained a relatively stable EMI shielding
efficiency even after cyclic bending and abrasion tests. Moreover,
the composite cotton fabric possessed a high limiting oxygen index
(LOI) of 45.3% and self-extinguishing properties with the peak heat
release rate (PHHR) and total heat release (THR) reduced by 73 and
67%, respectively, than the pure cotton fabric, indicating the outstanding
flame retardancy
Table_1_In vitro interactions of proton pump inhibitors and azoles against pathogenic fungi.docx
IntroductionAzole resistance has been increasingly reported and become an issue for clinical managements of invasive mycoses. New strategy with combination therapy arises as a valuable and promising alternative option. The aim of the present study is to investigate the in vitro combinational effect of proton pump inhibitors (PPIs) and azoles against pathogenic fungi.MethodsIn vitro interactions of PPIs including omeprazole (OME), lansoprazole (LAN), pantoprazole (PAN), and rabeprazole (RAB), and commonly used azoles including itraconazole (ITC), posaconazole (POS), voriconazole (VRC) and fluconazole (FLC), were investigated via broth microdilution chequerboard procedure adapted from the CLSI M27-A3 and M38-A2. A total of 67 clinically isolated strains, namely 27 strains of Aspergillus spp., 16 strains of Candida spp., and 24 strains of dematiaceous fungi, were studied. C. parapsilosis (ATCC 22019) and A. flavus (ATCC 204304) was included to ensure quality control.ResultsPPIs individually did not exert any significant antifungal activity. The combination of OME with ITC, POS, or VRC showed synergism against 77.6%, 86.6%, and 4% strains of tested pathogenic fungi, respectively, while synergism of OME/FLC was observed in 50% strains of Candida spp. Synergism between PAN and ITC, POS, or VRC was observed against 47.8%, 77.6% and 1.5% strains of tested fungi, respectively, while synergism of PNA/FLC was observed in 50% strains of Candida spp. Synergism of LAN with ITC, POS, or VRC was observed against 86.6%, 86.6%, and 3% of tested strains, respectively, while synergism of LAN/FLC was observed in 31.3% strains of Candida spp. Synergy of the combination of RAB with ITC, POS, or VRC was observed against 25.4%, 64.2%, and 4.5% of tested strains, respectively, while synergism of RAB/FLC was observed in 12.5% of Candida spp.. Among PPIs, synergism was least observed between RAB and triazoles, while among triazoles, synergism was least observed between VRC and PPIs. Among species, synergy was much more frequently observed in Aspergillus spp. and dematiaceous fungi as compared to Candida spp. Antagonism between PPIs with ITC or VRC was occasionally observed in Aspergillus spp. and dematiaceous fungi. It is notable that PPIs combined with azoles showed synergy against azole resistant A. fumigatus, and resulted in category change of susceptibility of ITC and POS against Candida spp.DiscussionThe results suggested that PPIs combined with azoles has the potential to enhance the susceptibilities of azoles against multiple pathogenic fungi and could be a promising strategy to overcome azole resistance issues. However, further investigations are warranted to study the combinational efficacy in more isolates and more species, to investigate the underlying mechanism of interaction and to evaluate the potential for concomitant use of these agents in human.</p
Additional file 2: of Evaluation of the effectiveness of a WHO-5A model based comprehensive tobacco control program among migrant workers in Guangdong, China: a pilot study
TREND Statement Checklist of this intervention. (PDF 509 kb
Electrospun Nanofibrous Membranes Surface-Decorated with Silver Nanoparticles as Flexible and Active/Sensitive Substrates for Surface-Enhanced Raman Scattering
The development of novel nanomaterials with well-controlled
morphologies/structures
to achieve excellent activities/sensitivities in surface-enhanced
Raman scattering (SERS) is crucial in advancing the high-performance
SERS detections of chemical and biological species. In this study,
amidoxime surface-functionalized polyacrylonitrile (ASFPAN) nanofibrous
membranes surface-decorated with silver nanoparticles (Ag NPs) were
prepared via the technique of electrospinning followed by the method
of seed-mediated electroless plating. High SERS activities/sensitivities
were observed from the ASFPAN-Ag NPs nanofibrous membranes, while
the density and size of Ag NPs had an important impact on the SERS
activity/sensitivity. The results confirmed that the enhancement of
Raman signals is due to the presence of hot spots between/among Ag
NPs on the nanofiber surfaces. Electrospun nanofibrous membranes surface-decorated
with Ag NPs were mechanical flexible/resilient and could be used as
highly active/sensitive SERS substrates for a broad range of applications
Additional file 1: of Evaluation of the effectiveness of a WHO-5A model based comprehensive tobacco control program among migrant workers in Guangdong, China: a pilot study
Study Protocol of this intervention. (PDF 210 kb
<i>Aspergillus fumigatus ctf1</i>–a novel zinc finger transcription factor involved in azole resistance
Elucidating the mechanisms underlying antifungal resistance in Aspergillus fumigatus, discovering new antifungal targets, and developing drugs to inhibit resistance are the key approaches to treating A. fumigatus infections. Here, we investigated the function of ctf1 (AFUA_1G03800), a gene encoding a C6 transcription factor. Homologous recombination replacement technology was employed to construct ctf1-knockout and revertant strains. Fungal morphological observations revealed that the growth of the knockout strain was slower, showing fewer conidia. The minimum inhibitory concentration of triazoles was determined by performing the E-test and by using the micro-liquid-based dilution method. The results indicated that ctf1 deletion decreased the susceptibility of A. fumigatus to voriconazole by 2-fold. The decreased antifungal sensitivity of Δctf1 can be attributed to the increased ergosterol content and the overexpression of mdr1, mdr2, and mdr4. Thus, our results on the function of ctf1 contribute to the elucidation of the mechanisms underlying A. fumigatus resistance and the factors associated with A. fumigatus virulence.</p
Modulating the Structure and Properties of Poly(sodium 4-styrenesulfonate)/Poly(diallyldimethylammonium chloride) Multilayers with Concentrated Salt Solutions
Poly(sodium 4-styrenesulfonate) (PSS)/poly(diallyldimethylammonium chloride) (PDADMAC) multilayers were treated with 1–5 M NaCl solutions, resulting in continuous changes in the physicochemical properties of the multilayers. Significant mass loss was observed when the salt concentration was higher than 2 M and reached as high as 72% in a 5 M NaCl solution. The disassembly occurred initially in the superficial layers and then developed in the bulk multilayers. For the multilayers with PDADMAC as the outmost layer, the molar ratio of PSS/PDADMAC was increased and the surface chemistry was changed from PDADMAC domination below 2 M NaCl to PSS domination above 3 M NaCl. Owing to the higher concentrations of uncompensated for polyelectrolytes at both lower and higher salt concentrations, the swelling ratio of the multilayers was decreased until reaching 3 M NaCl and then was increased significantly again. The salt-treated PSS/PDADMAC thin films are expected to show different behaviors in terms of the physical adsorption of various functional substances, cell adhesion and proliferation, and chemical reaction activity
Determinants of Consistent Condom Use among College Students in China: Application of the Information-Motivation-Behavior Skills (IMB) Model
<div><p>Background</p><p>Due to the increase incidents of premarital sex and the lack of reproductive health services, college students are at high risk of HIV/AIDS infections in China. This study was designed to examine the predictors of consistency of condom use among college students based on the Information-Motivation-Behavioral Skills (IMB) model and to describe the relationships between the model constructs.</p><p>Methods</p><p>A cross-sectional study was conducted to assess HIV/AIDS related information, motivation, behavioral skills and preventive behavior among college students in five colleges and universities in Nanjing, China. An anonymous questionnaire survey was conducted for data collection, and the structural equation model (SEM) was used to assess the IMB model.</p><p>Results</p><p>A total of 3183 participants completed this study. The average age was 19.90 years (SD = 1.43, range 16 to 25). 342 (10.7%) participants of them reported having had premarital sex, among whom 30.7% reported having had a consistent condom use, 13.7% with the experience of abortion (including the participants whose sex partner has the same experience), 32.7% of participants had experience of multiple sex partners. The final IMB model provided acceptable fit to the data (CFI = 0.992, RMSEA = 0.028). Preventive behavior was significantly predicted by behavioral skills (β = 0.754, <i>P</i><0.001). Information (β = 0.138, <i>P</i><0.001) and motivation (β = 0.363, <i>P</i><0.001) were indirectly affected preventive behavior, and was mediated through behavioral skills.</p><p>Conclusions</p><p>The results of the study demonstrate the utility of the IMB model for consistent condom use among college students in China. The main influencing factor of preventive behavior among college students is behavioral skills. Both information and motivation could affect preventive behavior through behavioral skills. Further research could develop preventive interventions based on the IMB model to promote consistent condom use among college students in China.</p></div