A particle trapping chip using the wide and uniform slit formed by a deformable membrane with air bubble plugs

We present a high-efficient particle trapping chip, where a wide and uniform slit is formed by a deformable membrane barrier with air bubble plugs. The previous particle trapping methods based on membrane barriers resulted in low trapping efficiency due to the non-uniform slit gap between the membrane and the substrate, especially at the side walls of rectangular channel. In the present method, the air bubble plugs remained in the extended microchannel during sample filling process, block the particle passage at the both side ends of the membrane, thus all particles flow through the uniform slit gap. Therefore, high-efficient particle trapping without particle loss can be achieved. The present particle trapping chip was composed of three layers: pneumatic (top), membrane and channel (bottom) layers. The membrane was deformed by the pneumatic pressure applied from the top layer. In the experimental study using 10.3 μm-diameter polystyrene beads, the membrane barrier with the air bubble plugs successfully trapped the injected beads with the trapping efficiency of 100% at the flow rate of 10 μl/min, while the barrier without the air bubble plugs showed low efficiency of 20%. At the increased flow rate of 20 μl/min, beads were still trapped with trapping efficiency over 98% in the present device. By using a mixture of 5.7 and 10.3 μm-diameter beads, we also verified the present method was capable to trap and release the beads selectively according to their size with the release efficiency of 95.1%. The present simple and effective particle trapping device is applicable for the high-efficient bioparticle isolation and recovery in the micro total analysis system.     

Apatite fission-track data from upper Cretaceous formations in the Yuan'an Graben (China): Constraints on the timing of synsedimentary fault activity

Apatite fission-track signatures of upper Cretaceous Formations in the Yuan'an Graben are made to constraint on the timing of the Yuan'an and Tongchenghe synsedimentary fault activity. The apatite fission-track ages range from 102.0 ± 14.6 to 84.1 ± 3.7 Ma with P(χ²) >0.05; the mean confined track lengths of 14.18 ± 0.09 and 14.16 ± 0.08 μm with mean D_par values of 2.25 ± 0.02 and 2.26 ± 0.03 μm, respectively. These data are interpreted as dating their source-area exhumation, recording the exhumation and cooling of the footwall during major normal faulting. The results indicate that the timing of the Yuan'an and Tongchenghe synsedimentary fault activity occurred at 117–82 Ma and the intensive movement at 100–82 Ma; the onset time of extension in Jianghan Basin is ca. 117 Ma, which is related to the lithospheric extension associated with the subduction of the Pacific Plate beneath the Asian Plate.     

Doubly radiative thermal neutron capture in 2H and 16O: Experiment and theory

Measurements and calculations are presented for the cross sections for two-photon emission following thermal neutron capture in ²H and ¹⁶O. Upper limits for σ_2γ were measured in both cases. For ²H, σ_2λ = 8 ± 15 μb, for γ-rays in the energy region 700 < E_γ < 5550 keV. A detailed threeparticle calculation gives σ_2γ^tot = 26 nb. For ¹⁶O, the experimental result is σ_2γ = 3 ± 19 μb for 1200 < E_γ < 2943 keV. A single-particle, direct-capture calculation for ¹⁶O gives σ_2γ^tot = 41 nb. Contributions from excitation of the giant dipole state of the core change this result by ± 16 %. In a separate measurement the total cross section for ¹⁶O(n, γ)¹⁷O was measured to be 202 ± 28 μb. Branching ratios of (82 ± 3)% and (18 ± 3)% were determined for decays to the 3055 and 871 keV levels of ¹⁷O, respectively.     

Torsional frequency,barrier to internal rotation,and dipole moment of N-sulphinylaniline from microwave rotational spectra

Microwave spectra of the ground and first three excited torsional states of N-sulphinylaniline have been assigned. The variation of the inertial defect with torsional number shows the molecule to be planar. The torsional frequency has been determined as ν = 41.1 cm^?1 and the barrier to internal rotation as V₂ = 2.3 kcal/mole. From the splittings of the Stark lobes of some lines the values μ_a = 2.20 ± 0.06, μ_b = 0.664 ± 0.005, and μ_tot = 2.30 ± 0.06 were obtained.     

Nanostructural analysis of ZnO:Al thin films for carrier-transport mechanisms

The carrier mobility of sputter-deposited Al-doped ZnO transparent-conducting (ZnO:Al) thin films was controlled between 22 and 48 cm²/Vs by varying the ZnO:Al seed layer. The statistical distribution of the [001] grain misorientation was characterized from the X-ray diffraction rocking curve in the range from 0.043 (2.5°) to 0.179 rad (10.2°). The grain-boundary energy barriers (E_b) from Seto's model [1] clearly exhibit linear dependence on the grain-boundary misorientation angle (ω) according to the equation E_b = 78 ± 4 + 173 ± 32 ω meV.     

Microwave spectrum of silyl methyl ether

The microwave spectra of silyl methyl ether, SiH₃OCH₃, and its isotopic modifications, SiH₃OCD₃, SiD₃OCH₃, and SiD₃OCD₃, have been observed and assigned. Large splittings arising from the internal rotation of the methyl top and somewhat smaller splittings arising from the internal rotation of the silyl top are observed. The “effective barrier” to internal rotation of the methyl top is approximately 550 cal/mole. The effective barrier to internal rotation of the silyl top is approximately 1100 cal/mole. The internal rotation of the two tops is strongly coupled, but no values for the potential coupling constants have been obtained. The dipole moment has been determined to be 1.15 ± 0.02 D (|μ_a| = 0.647 ± 0.01 and |μ_b| = 0.95 ± 0.02 D) from measurements of the Stark effect.     

Rotation-inversion spectrum of methylaminoethane

Microwave spectral assignments have been made for the ground and several excited vibrational states of the normal and amino d₁ species of methylaminoethane. The inversion-rotation spectrum is consistent with a trans rotameric form with an amino inversion barrier of ～5.2 kcal mole^?1. The dipole moment of 8.88 ± 0.02 Debye has components |μ_a| = 0.00 ± 0.03, |μ_b| = 0.25 ± 0.03, and $\text{|〈 ± μ}{}_{\mathrm{c}}\text{? 〉| = 0.84 ± 0.01}$ Debye. The normal species N¹⁴ nuclear quadrupole coupling constants are (in MHz) 2.82 ± 0.09, 0.88 ± 0.13, and ?3.70 ± 0.09 for χ_aa, χ_bb, and χ_cc, respectively.     

Superhydrophobic properties of a hierarchical structure using a silicon micro-tip array decorated with ZnO nanowires

In this study, wetting properties of a hierarchical structure using a silicon micro-tip array covered with ZnO nanowire are characterized, and compared with hierarchical structures composed of micro-pillars for micro-scale roughness. The superhydrophobicity of a surface can be efficiently enhanced by using a micro-tip array, compared with a micro-pillar structure, because a micro-tip structure with high aspect ratio and small apex radius can significantly reduce fractions of liquid droplet area in contact, maintaining the droplet in the regime of the Cassie state. The micro-tip array was simply fabricated by combining anisotropic and isotropic silicon etching processes with one-step photolithography and a single etch mask. The measured height and aspect ratio of the fabricated micro-tip was around 40 μm and 8, respectively, when the center-to-center distance between micro-tips was 30 μm. The maximum CA on the hierarchical surface using the micro-tip array was measured to be 165.0 ± 2.3° with a period of 30 μm, while the hierarchical surface using the micro-pillar array showed the maximum CA of 158.6 ± 1.1° with 20 μm-diameter and 70 μm-gap between micro-pillars. The smallest CAH on the hierarchical micro-tip array was measured to be 5.0 ± 0.3° for the center-to-center distance between micro-tips of 30 μm.     

Microwave spectrum,dipole moment,and conformation of 3-methylcyclopentanone

The rotational spectrum of 3-methylcyclopentanone has been observed in the frequency region from 18.0 to 26.5 GHz. Both a-type and b-type transitions in the ground vibrational state and a-type transitions in five excited states have been assigned. The ground state rotational constants are determined to be A = 5423.32 ± 0.18, B = 1949.51 ± 0.01, and C = 1529.59 ± 0.01 MHz. Analysis of the measured quadratic Stark effects gives the dipole moment components ∥μ_a∥ = 2.97 ± 0.02, ∥μ_b∥ = 1.00 ± 0.03, ∥μ_c∥ = 0.18 ± 0.06, and the total dipole moment ∥μ_t∥ = 3.14 ± 0.03 D. These data are consistent with a twisted-ring conformation with a methyl group in the equatorial position.     

Microwave spectrum of gauche-isopropylphosphine

The microwave spectra of isopropylphosphine has been recorded in the region 12.4–40.0 GHz. Both a- and b-type transitions were observed and assigned. The rigid rotor rotational constants were determined to be A = 7633.34 ± 0.09, B = 4243.36 ± 0.02, and C = 3045.84 ± 0.02 MHz for (CH₃)₂CHPH₂ and A = 7226.47 ± 0.05, B = 4041.06 ± 0.02, and C = 2946.85 ± 0.02 MHz for (CH₃)₂CHPD₂. Dipole moment components of |μ_a| = 1.15 ± 0.01, |μ_b| = 0.43 ± 0.01, |μ_c| = 0.03 ± 0.02 and |μ_t| = 1.23 ± 0.01 were determined from the Stark effect. From the microwave spectra, the Stark effect and the experimental rotational constants, the assigned spectrum has been identified to result from the gauche form and this conformer is believed to be more stable than the other form which is present at room temperature.     

Microwave spectrum and barrier to internal rotation of 1-chloro-2-butyne

Rotational transitions of the μ_a and μ_b type have been identified with microwave-microwave double resonance measurements for 1-chloro-2-butyne in the ground vibrational state. In the first excited state of the methyl torsion only μ_a-type transitions have been identified. The A-type transitions of the ground vibrational state can be described perfectly by the rigid rotor approximation with centrifugal corrections. Using the internal axis method the barrier to internal rotation was determined from the A,E splittings: V₃ = 10.05 ± 0.09 cm⁻¹. A model which allowed for geometry relaxation upon internal rotation was used to fit one set of parameters to the transition frequencies of both ground state and first excited torsional state. The sixfold contribution to the barrier was found to be negligible: V₆ = −0.4 ± 0.3 cm⁻¹.     

Dipole moment of the HO2 radical from its microwave spectrum

Stark effects are measured for the 1₀₁ ← 0₀₀, 7₁₇ ← 8₀₈, and 9₀₉ → 8₁₈ transitions of the HO₂ free radical. The unresolved Stark patterns of the b-type transitions are analyzed by the use of computer simulation. Second-order perturbation theory, including the effect of spin-doublings in the denominators, is used for the calculation of the Stark effect coefficients. The dipole moment determined is μ_a = 1.412 ± 0.033 D, μ_b = 1.541 ± 0.016 D, and μ_total = 2.090 ± 0.034 D.     

Infrared,Raman, and microwave spectra of ethaneselenol and the determination of the barriers to internal rotation

The infrared, Raman, and microwave spectra of gaseous ethaneselenol have been investigated. The rotational constants for both the more stable gauche and for the trans conformers are reported for the Et⁷⁸SeH, Et⁷⁸SeD, Et⁸⁰SeH, and Et⁸⁰SeD isotopic species. A proposed structure has been derived from a least-squares analysis of the moments of inertia. Dipole moment components have been obtained from each conformer using second-order Stark effects. For the gauche conformer, they are μ_a = 1.42 ± 0.01, μ_c = 0.37 ± 0.03, and μ_total = 1.47 ± 0.01 D. For the trans isomer they are μ_a = 1.217 ± 0.002, μ_b = 0.850 ± 0.001, and μ_total = 1.485 ± 0.002 D. The methyl barrier to internal rotation was calculated using observed frequencies obtained from the infrared and Raman spectra; a value of 3.59 ± 0.01 kcal/mole was obtained. Asymmetric potential functions have been calculated for both the EtSeH and EtSeD isotopic species. For the light species the potential constants for internal rotation around the CSe bond are V₂ = ?96.4 ± 1, V₃ = 432 ± 4, and V₆ = ?20 ± 2 cm^?1. The difference between ground-state energy levels of the two conformers was found to be 66 cm^?1. A vibrational assignment based on infrared and Raman spectra of the gaseous phase is presented.     

Measurement of the ortho-para transition rate in the pμp molecule and deduction of the pseudoscalar coupling constant gpμ

The ortho-para transition rate in the pμp molecule has been found experimentally to be λ_OP = (4.1 ± 1.4) × 10⁴ s^?1. Our recent result for the muon capture rate in liquid hydrogen can now be interpreted to extract the ortho-molecular capture rate: λ_OM = (531 ± 33) s^?1. A deduction of the pseudoscalar coupling constant g_p^μ is presented: we find g_p^μ = 8.7 ± 1.9.     

Comparative ultrastructure of spermatozoa of the redclaw Cherax quadricarinatus and the yabby Cherax destructor (Decapoda,Parastacidae)

Ultrastructure of spermatozoa of redclaw Cherax quadricarinatus and yabby Cherax destructor were described and compared. The acrosome complex and nucleus are located at the anterior and posterior region of the spermatozoon, respectively. The acrosome is a complex vesicle divided into two parts: the main body of the acrosome appears as a dense cup-shaped structure in longitudinal sagittal view, with the subacrosome zone occupying the central area of the vesicle. The acrosome is larger in C. quadricarinatus (width 2.37 ± 0.27 μm, length 1.31 ± 0.23 μm) than in C. destructor (width 1.80 ± 0.27 μm, length 1.01 ± 0.15 μm). There was no significant difference in L:W ratios of the studied species. The subacrosome zone in both species consists of two areas of different electron density. The nucleus is substantially decondensed and irregular in shape, with elaborate extended processes. The examined species exhibited a well-conserved structure of crayfish spermatozoon, similar to those of Cherax cainii and Cherax albidus. Small acrosome size, the absence of radial arms, and an extracellular capsule seem to be the morphological features that mostly distinguish Cherax from the Astacidae and Cambaridae.     

The microwave spectrum of a second N-gauche rotamer of allylamine

The microwave spectra of the ground and five excited states of a second gauche rotamer of allylamine have been measured and assigned. Three of the excited states belong to the same mode, most probably the CC torsion, the second and third vibrational states present a symmetrical splitting due to tunneling effect. The spectrum was conclusively identified as due to the N-gauche, lone-electron-pair trans form by means of the N-quadrupole coupling constants and dipole moment components. The variation observed for the quadrupole coupling constants in the different vibrationally excited states was explained by a suitable model. The ground state constants are (in MHz) A₀ = 23 957.05 ± 0.048, B₀ = 4 229.96 ± 0.025, C₀ = 4 154.91 ± 0.025, χ_aa = ? 1.48 ± 0.04, χ_bb - χ_cc = ? 1.42 ± 0.04, and (in D) ∥μ_a∥ = 0.766 ± 0.010, ∥μ_b∥ = 0.700 ± 0.005, ∥μ_c∥ = 0.290 ± 0.020.The excited states of the N-cis, lone-electron-pair trans form were also measured and assigned; two of these states appear to belong to the CC torsion as indicated by their intertial defects. The potential hindering the internal CC rotation was calculated using the relative intensity data of the N-cis and N-gauche forms as well as the tunneling splittings. A three-term cosine potential was fitted to the data yielding (in cm^?1) V₁ = ? 77 ± 85, V₂ = 170 ± 126, V₃ = 663 ± 95. The Dennison-Uhlenbeck potential was used for an approximate calculation of the N-trans barrier separating the two identical N-gauche forms. The barrier obtained was 1.9 ± 0.3 Kcal/mole.     

Diffusivity mapping of the ovaries: Variability of apparent diffusion and kurtosis variables over the menstrual cycle and influence of oral contraceptives

PurposeWe aimed to investigate whether quantitative diffusivity variables of healthy ovaries vary during the menstrual cycle and to evaluate alterations in women using oral contraceptives (OC).MethodsThis prospective study (S-339/2016) included 30 healthy female volunteers, with (n = 15) and without (n = 15) intake of OC between 07/2017 and 09/2019. Participants underwent 3T diffusion-weighted MRI (b-values 0–2000 s/mm²) three times during a menstrual cycle (T1 = day 1–5; T2 = day 7–12; T3 = day 19–24). Both ovaries were manually three-dimensionally segmented on b = 1500 s/mm²; apparent diffusion coefficient (ADC) calculation and kurtosis fitting (D_app, K_app) were performed. Differences in ADC, D_app and K_app between time points and groups were compared using repeated measures ANOVA and t-test after Shapiro-Wilk and Brown-Forsythe test for normality and equal variance.ResultsIn women with a natural menstrual cycle, ADC and kurtosis variables showed significant changes in ovaries with the dominant follicle between T1 vs T2 and T1 vs T3, whilst no differences were observed between T2 vs T3: ADC ± SD for T1 1.524 ± 0.160, T2 1.737 ± 0.160, and T3 1.747 ± 0.241 μm²/ms (p = 0.01 T2 vs T1; p = 1.0 T2 vs T3, p = 0.003 T3 vs T1); D_app ± SD for T1 2.018 ± 0.140, T2 2.272 ± 0.189, and T3 2.230 ± 0.256 μm²/ms (p = 0.003 T2 vs T1, p = 1.0 T2 vs T3, p = 0.02 T3 vs T1); K_app ± SD for T1 0.614 ± 0.0339, T2 0.546 ± 0.0637, and T3 0.529 ± 0.0567 (p < 0.001 T2 vs T1, p = 0.86 T2 vs T3, p < 0.001 T3 vs T1). No significant differences were found in the contralateral ovaries or in females taking OC.ConclusionPhysiological cycle-dependent changes in quantitative diffusivity variables of ovaries should be considered especially when interpreting radiomics analyses in reproductive women.     

Characterisation of thin films obtained by laser ablation of Ge28Se60Sb12 glasses

Films of nominal composition Ge₂₈Se₆₀Sb₁₂ were deposited on microscope slides by pulsed laser deposition (PLD), using either bulk or powdered glassy targets and a Nd:YAG laser (λ=266 nm). The films with thickness comprised between 400 and 800 nm showed a smooth and dense morphology. They were homogeneous in composition all over the samples with a composition somewhat deficient in selenium compared to the nominal one: Ge_28.1±0.3Se_56.1±0.1Sb_15.8±0.2 and Ge_29.0±0.3Se_55.5±0.1Sb_15.5±0.2 for films obtained from powdered glassy targets and bulk targets, respectively. The optical characteristics of the films were extracted from the transmission spectra recorded between 250 and 2500 nm. In particular, the refractive index at 1.5 μm was found to be 2.75±0.03, close to that of the bulk glass, as expected for dense films. The decrease in the optical band gap and the increase in the Urbach absorption edge with the film thickness were attributed to an increase in disorder.     

Microwave spectrum of phenyl isocyanate

The microwave spectra of the ground state and three excited states of the most abundant species of phenyl isocyanate have been recorded between 8 and 40 GHz. From ^aR-type transitions the ground-state rotational constants were calculated. The A value showed clearly a tilt of the NCO group from the C_2v axis. They yielded the r₀-type parameters. A centrifugal distortion treatment confirmed the validity of the rigid rotor approximation. The dipole moment components μ_a and μ_b were derived from the field strength dependence of six Stark lobes of five transitions. The values found were μ_a = (2.50 ± 0.02) D, μ_b < 0.2 D. From relative intensity measurements, the lowest vibrational excitation energies were determined. We assigned the lowest one to the NCO group torsion. All ^aR-type transitions of excited states were found unsplit by the internal rotation of the NCO group. The weakness of the μ_b dipole moment component and of the overall spectrum intensity did not allow us to find μ_b-type transitions and so, no splitting was observed on the ground-state spectrum. An evaluation of the V₂ high barrier is given.     

Microwave spectral studies of rotational isomerism in substituted ethanethiols: 2-Aminoethanethiol and 2-chloroethanethiol

Microwave spectra were observed and analyzed for 2-aminoethanethiol and 2-chloroethanethiol. The amino compound exists in two gauche rotameric conformations, one exhibiting an intramolecular SH?N hydrogen bond. The hydrogen-bonded conformer lies higher in energy by 274 ± 90 cal mole^?1 and has the following rotational constants (in MHz): A = 12 040.1 ± 11.3, B = 3352.24 ± 0.03, and C = 2881.99 ± 0.03. For the non-hydrogen-bonded conformer the rotational constants (in MHz) are A = 11 929.9 ± 10.2, B = 3395.01 ± 0.03, and C = 2877.82 ± 0.03. Dipole moment measurements for the H-bond conformer led to μ_a = 2.68 D, μ_b = 0.88 D, and μ_c = 0.37 D, while for the non-H-bond form the values are μ_a = 1.51 D, μ_b = 0.0 D, and μ_c = 0.62 D. In the case of chloroethanethiol, the only assigned spectral lines were the unresolved J → J + 1 a-type bands of a trans conformation. For this molecule the combination rotational constant B + C has the value 2955.17 ± 0.02 MHz for the ³⁵Cl species and 2879.73 ± 0.02 MHz for the ³⁷Cl species.