•The properties of Si and N doped diamond-like carbon (Si–N–DLC) have been examined.•The internal stress on Si–N–DLC was lower than that on N doped DLC.•The optical bandgap of Si–N–DLC showed an ...increasing trend with increasing N content.•Si–N–DLC/p-type Si junctions annealed in a vacuum showed rectifying characteristics.
We have investigated the effects of silicon (Si) doping on the chemical bonding states and the electrical, optical, and mechanical properties of nitrogen-doped diamond-like carbon (N−DLC) films prepared via plasma-enhanced chemical vapor deposition using hydrogen as a dilution gas. N doping accelerated the formation of clustered sp2 C in N−DLC films, whereas the clustering was almost suppressed in Si and N doped DLC (Si−N−DLC) films. Sp3 C sites in the Si–N–DLC films were higher than those in the N–DLC films. For the Si−N−DLC films, sp3 C-N bonds were preferentially formed compared with the sp2 C=N bonds. The internal stress on the Si−N−DLC films was lower than that on the N−DLC films. The Si−N−DLC films exhibited higher optical bandgaps than the N−DLC films. As the N2 flow ratio increased, the optical bandgap of the Si−N−DLC films showed an increasing trend, whereas that of the N−DLC films showed an opposite trend. The current−voltage characteristics of Si−N−DLC/p-type Si heterojunctions were not rectifying; however, after postdeposition annealing, the heterojunctions exhibited rectifying characteristics.
Gene therapy promises to treat diseases that arise from genetic abnormalities by correcting the underlying cause of the disease rather than treating the associated symptoms. Successful transfer of ...nucleic acids into cells requires efficient delivery vehicles that protect the cargo and can penetrate the appropriate cellular barriers before releasing their contents. Many viral vectors and synthetic polycationic vectors for nucleic acid delivery do not translate well from in vitro to in vivo applications due to their instability and toxicity. We synthesized and characterized a library of biocompatible low charge density polymers from a family of poly(amine-co-ester) (PACE) terpolymers produced via enzyme catalyzed polymerization. PACE polymers are highly customizable; we found that the terpolymer composition can be optimized to produce efficient transfection of various nucleic acidsincluding DNA plasmids, mRNA, and siRNAin specific cell types with low toxicity. Our findings suggest that the unique tunability of PACEs offers new tools for gene therapy and other biomedical applications.
A
bstract
Charged lepton flavor violation is forbidden in the Standard Model but possible in several new physics scenarios. In many of these models, the radiative decays
τ
±
→
ℓ
±
γ
(
ℓ
=
e, μ
) are ...predicted to have a sizeable probability, making them particularly interesting channels to search at various experiments. An updated search via
τ
±
→
ℓ
±
γ
using full data of the Belle experiment, corresponding to an integrated luminosity of 988 fb
−
1
, is reported for charged lepton flavor violation. No significant excess over background predictions from the Standard Model is observed, and the upper limits on the branching fractions,
B
(
τ
±
→
μ
±
γ
) ≤ 4
.
2 × 10
−
8
and
B
(
τ
±
→
e
±
γ
) ≤ 5
.
6 × 10
−
8
, are set at 90% confidence level.
We have deposited silicon-incorporated diamond-like carbon (Si-DLC) films by plasma-enhanced chemical vapor deposition using monomethylsilane (CH3SiH3; MMS) as a Si source, and systematically ...investigated the impacts of substrate bias and dilution gas on the mechanical and tribological properties of the Si-DLC films. The use of a pulse bias and hydrogen dilution is very effective in suppressing the generation of particles during the deposition. The internal stress of the Si-DLC films deposited using the pulse bias tended to be lower than that of the Si-DLC films deposited using a DC bias, while the hydrogen dilution resulted in the increase in the internal stress. On the other hand, the Si-DLC film deposited with H2 using the pulse bias showed the highest adhesion strength and the lowest friction coefficient. The use of the pulse bias resulted in the increase in the wear resistance.
•Effects of substrate bias and dilution gas on the properties of Si-DLC films have been investigated.•The Si-DLC film prepared using a pulse bias with H2 presents the highest adhesion strength.•The Si-DLC film prepared using a pulse bias with H2 shows the lowest friction coefficient.
We study B --> K(*)l+l- decays (l = e, mu) based on a data sample of 657 x 10(6) BB pairs collected with the Belle detector at the KEKB e+e- collider. We report the differential branching fraction, ...isospin asymmetry, K* polarization, and the forward-backward asymmetry (A(FB)) as functions of q2 = M(ll)(2)c2. The fitted A(FB) spectrum exceeds the standard model expectation by 2.7 standard deviations. The measured branching fractions are B(B --> K*l+l-) = (10.7(-1.0)(+1.1) +/- 0.9) x 10(-7) and B(B --> Kl+l-) = (4.8(-0.4)(+0.5) +/- 0.3) x 10(-7), where the first errors are statistical and the second are systematic, with the muon to electron ratios R(K*) = 0.83 +/- 0.17 +/- 0.08 and R(K) = 1.03 +/- 0.19 +/- 0.06.
The cross section for e+ e- --> pi+ pi- psi(2S) between threshold and sqrts=5.5 GeV is measured using 673 fb(-1) of data on and off the Upsilon(4S) resonance collected with the Belle detector at ...KEKB. Two resonant structures are observed in the pi+ pi- psi(2S) invariant-mass distribution, one at 4361 +/- 9 +/- 9 MeV/c2 with a width of 74 +/- 15 +/- 10 MeV/c2, and another at 4664 +/- 11 +/- 5 MeV/c2 with a width of 48 +/- 15 +/- 3 MeV/c2, if the mass spectrum is parametrized with the coherent sum of two Breit-Wigner functions. These values do not match those of any of the known charmonium states.
We report a study of B→(J/ψγ)K and B→(ψ'γ)K decay modes using 772×10⁶ B ̅B events collected at the Υ(4S) resonance with the Belle detector at the KEKB energy-asymmetric e(+)e(-) collider. We observe ...X(3872)→J/ψγ and report the first evidence for χ(c2)→J/ψγ in B→(X_{c ̅cγ)K decays, while in a search for X(3872)→ψ'γ no significant signal is found. We measure the branching fractions, B(B(±)→X(3872)K(±))B(X(3872)→J/ψγ)=(1.78(-0.44)(+0.48)±0.12)×10(-6), B(B(±)→χ(c2)K(±))=(1.11(-0.34)(+0.36)±0.09)×10(-5), B(B(±)→X(3872)K(±))B(X(3872)→ψ'γ)<3.45×10⁶ (upper limit at 90% C.L.), and also provide upper limits for other searches.
We have grown aluminum nitride (AlN) films on Si(110) substrates by pulsed laser deposition (PLD), and investigated the effects of laser power on the crystallinity and surface morphology of the AlN ...films. First, we epitaxially grew a fairly flat, high-quality AlN film, which contained no rotation domains, onto the Si(110) substrate in a well-lattice-matched relationship. Secondly, we formed a SiC interfacial buffer layer on the AlN film to grow a high-quality 3C-SiC film on the SiC buffer layer by PLD, which gave rise to a 3C-SiC(111)3×3 surface. The root-mean-square-roughness value of the SiC film was smaller than the previously reported values of SiC/AlN multilayers on Si(100) and Si(111) substrates. Thirdly, we grew graphene by annealing the SiC film at a high temperature in an ultra-high vacuum. It was demonstrated that the qualified graphene layer without rotation domains was grown on the SiC film. The formation of voids and the outdiffusion of Al and N atoms from the AlN film were successfully suppressed during the high-temperature annealing.
•A graphene layer is grown epitaxially on SiC/AlN/Si(110).•AlN films are grown epitaxially on Si(110) substrate in a well-lattice-matched relationship.•AlN films contain no rotation domains.•A SiC film is grown on a SiC buffer layer, which gives rise to a 3C-SiC(111)3×3 surface.
An extensive outbreak of staphylococcal food poisoning occurred in Kansai district in Japan. As many as 13 420 cases frequently ingested dairy products manufactured by a factory in Osaka City. The ...main ingredient of these dairy products was powdered skim milk manufactured by a factory in Hokkaido. Staphylococcal enterotoxin A (SEA) (≤0·38 ng/ml) was detected in low-fat milk and approx. 3·7 ng/g in powdered skim milk. The total intake of SEA per capita was estimated mostly at approx. 20-100 ng. The assumed attack rate was considerably lower than those reported in previous outbreaks. SEA exposed at least twice to pasteurization at 130 °C for 4 or 2 s retained both immunological and biological activities, although it had been partially inactivated. The present outbreak was unusual in that the thermal processes had destroyed staphylococci in milk but SEA had retained enough activity to cause intoxication.
We search for lepton-flavor-violating τ→ℓV0 decays, where ℓ is an electron or muon and V0 is one of the vector mesons ρ0, ϕ, ω, K⁎0 and K¯⁎0. We use 854 fb−1 of data collected with the Belle detector ...at the KEKB asymmetric-energy e+e− collider. No evidence for a signal is found in any decay mode, and we obtain 90% confidence level upper limits on the individual branching fractions in the range (1.2–8.4)×10−8.
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