Accuracy Evaluation of The Depth of Six Kinds of Sperm Counting Chambers for both Manual and Computer-Aided Semen Analyses.

BACKGROUND: Although the depth of the counting chamber is an important factor influencing sperm counting, no research has yet been reported on the measurement and comparison of the depth of the chamber. We measured the exact depths of six kinds of sperm counting chambers and evaluated their accuracy. MATERIALS AND METHODS: In this prospective study, the depths of six kinds of sperm counting chambers for both manual and computer-aided semen analyses, including Makler (n=24), Macro (n=32), Geoffrey (n=34), GoldCyto (n=20), Leja (n=20) and Cell-VU (n=20), were measured with the Filmetrics F20 Spectral Reflectance Thin-Film Measurement System, then the mean depth, the range and the coefficient of variation (CV) of each chamber, and the mean depth, relative deviation and acceptability of each kind of chamber were calculated by the closeness to the nominal value. Among the 24 Makler chambers, 5 were new and 19 were used, and the other five kinds were all new chambers. RESULTS: The depths (mean ± SD, µm) of Makler (new), Macro and Geoffrey chambers were 11.07 ± 0.41, 10.19 ± 0.48 and 10.00 ± 0.28, respectively, while those of GoldCyto, Leja and Cell-VU chambers were 23.76 ± 2.15, 20.49 ± 0.22 and 24.22 ± 2.58, respectively. The acceptability of Geoffrey chambers was the highest (94.12%), followed by Macro (65.63%), Leja (35%) and Makler (20%), while that of the other two kinds and the used Makler chamber was zero. CONCLUSION: There existed some difference between the actual depth and the corresponding nominal value for sperm counting chambers, and the overall acceptability was very low. Moreover, the abrasion caused by the long use, as of Makler chamber, for example, may result in unacceptability of the chamber. In order to ensure the accuracy and repeatability of sperm concentration results, the depth of the sperm counting chamber must be checked regularly.

[Characteristics of phosphorus adsorption and desorption of soils from wetlands recovered from farmlands in Caizi Lake].

In this study, topsoil samples were collected from wetlands recovered from farmlands respectively for 3, 5, 9 and 11 years around Caizi Lake, Anhui, China. Their characteristics of adsorption and desorption of phosphorus were examined with comparison to soils sampled from an adjacent vegetable farmland and a non-cultivated wetland. Phosphorus adsorption curves of all studied soils could be modeled by Langmuir and Freundlich equations (P < 0.01). The maximum P adsorption (Xm), adsorption constant K and maximum buffer capacity (MBC) of all the 6 soil samples were in the ranges of 478-1074 mg x kg(-1), 0.14-0.61 and 68.6-661.5 mg x kg(-1), respectively. These three parameters all tented to increase with the recovered years but did not reach the values of the non-cultivated wetland. However, the P desorption rate ranging from 6.2% to 14.6%, increased first and then decreased with the recovered years and was significantly higher than that of the non-cultivated wetland. It was concluded that the P immobilization would increase with the recovery years of cultivated wetlands, which could be affected by the soil organic carbon and clay contents of the wetland soil.

Gender-related difference in bloodstain RNA ratio stored under uncontrolled room conditions for 28 days.

Bloodstain age is a parameter that can be used in crime scene investigations. Bloodstain age can be determined by measuring the 18S rRNA:ß-actin mRNA ratio by Reverse Transcription-quantitative PCR (RT-qPCR). Since this ratio is a function of time, it can be used as an estimator of bloodstain age. However, it is important to validate the technique in a variety of scenarios before it can be applied. We investigated 18S rRNA:ß-actin mRNA ratio in bloodstains from sixteen Chinese subjects in 28 days under uncontrolled room conditions. The ratio changed in a linear fashion. It was also found that the subjects' gender affected the relationship between time and the RNA ratio.

[Influence of the depth of the sperm counting chamber on sperm motility].

OBJECTIVE: To investigate the influence of the depth of the sperm counting chamber on sperm motility. METHODS: We measured the depths of sperm counting chambers using the Filmetrics F20 Spectral Reflectance Thin-Film Measurement System. Then, according to the WHO5 manual, we analyzed 36 semen samples for the percentages of progressively motile sperm (PR) and non-progressively motile sperm (NP) and sperm motility (PR + NP) with the Ruiqi CFT-9201 computer-aided sperm analysis system, and compared the results of analysis. RESULTS: The depths of the 4 sperm counting chambers were 9.8, 12.7, 15.7 and 19.9 microm, respectively, and the obtained PR were (44.00 +/- 11.63), (41.96 +/- 12.62), (40.86 +/- 11.71) and (37.78 +/- 11.38)%, NP (13.54 +/- 3.01), (14.13 +/- 2.94), (14.91 +/- 3.02) and (16.53 +/- 2.77)%, and sperm motility (57.53 +/- 11.06), (56.08 +/- 11.97), (55.78 +/- 11.55) and (54.31 +/- 12.11)% from the 4 chambers, respectively. The depth of the sperm counting chamber was correlated negatively with PR (r = -0.993, P < 0.05) and sperm motility (r = -0.978, P < 0.05), but positively with NP (r = 0.989, P < 0.05). There were statistically significant differences between the 9.8 microm and 19.9 microm deep chambers in PR and NP (P < 0.05) though not in sperm motility among the 4 chambers of different depths. CONCLUSION: The impact of the depth of the sperm counting chamber on sperm motility should not be ignored, for the deviation of the results from the chambers of different depths may lead clinicians to incorrect diagnosis and consequently inappropriate therapeutic approaches. Different reference ranges of sperm motility need to be normalized in correspondence to the depths of sperm counting chambers.

Spectroscopic characterization of van der Waals interactions in a metal organic framework with unsaturated metal centers: MOF-74-Mg.

The adsorption energies of small molecules in nanoporous materials are often determined by isotherm measurements. The nature of the interaction and the response of the host material, however, can best be studied by spectroscopic methods. We show here that infrared absorption and Raman spectroscopy measurements together with density functional theory calculations, utilizing the novel van der Waals density functional vdW-DF, constitute a powerful approach to studying the weak van der Waals interactions associated with the incorporation of small molecules in these materials. In particular, we show how vdW-DF assists the interpretation of the vibrational spectroscopy data to uncover the binding sites and energies of these molecules, including the subtle dependence on loading of the IR asymmetric stretch mode of CO(2) when adsorbed in MOF-74-Mg. To gain a better understanding of the adsorption mechanism of CO(2) in MOF-74-Mg, the results are compared with CO within MOF-74-Mg.

Spectroscopic evidence for the influence of the benzene sites on tightly bound H2 in metal-organic frameworks with unsaturated metal centers: MOF-74-cobalt.

The role of low binding energy sites on the adsorption of H(2) in metal-organic frameworks (MOFs) with unsaturated metal centers has not been identified. For instance, the importance of the benzene sites on H(2) adsorption at the metal site in MOF-74 has not been established. We report here experimental evidence that unambiguously shows that the internal mode of H(2) adsorbed at the metal site undergoes both a frequency shift and a marked change in its dynamic dipole moment when H(2) is adsorbed at the next nearest neighbor "benzene" site in MOF-74-Co. The effect of loading (i.e., occupation of all benzene sites) also induces spectroscopic shifts in H(2) at the metal site. These interactions highlight the role of lower binding energy sites in H(2) adsorption.

Enhancing gas adsorption and separation capacity through ligand functionalization of microporous metal-organic framework structures.

Hydroxyl- and amino- functionalized [Zn(BDC)(TED)(0.5)]·2DMF·0.2H(2)O leads to two new structures, [Zn(BDC-OH)(TED)(0.5)]·1.5DMF·0.3H(2)O and [Zn(BDC-NH(2))(TED)(0.5)]·xDMF·yH(2)O (BDC=terephthalic acid, TED=triethylenediamine, BDC-OH=2-hydroxylterephthalic acid, BDC-NH(2)=2-aminoterephthalic acid). Single-crystal X-ray diffraction and powder X-ray diffraction studies confirmed that the structures of both functionalized compounds are very similar to that of their parent structure. Compound [Zn(BDC)(TED)(0.5)]·2DMF·0.2H(2)O can be considered a 3D porous structure with three interlacing 1D channels, whereas both [Zn(BDC-OH)(TED)(0.5)]·1.5DMF·0.3H(2)O and [Zn(BDC-NH(2))(TED)(0.5)]·xDMF·yH(2)O contain only 1D open channels as a result of functionalization of the BDC ligand by the OH and NH(2) groups. A notable decrease in surface area and pore size is thus observed in both compounds. Consequently, [Zn(BDC)(TED)(0.5)]·2DMF·0.2H(2)O takes up the highest amount of H(2) at low temperatures. Interestingly, however, both [Zn(BDC-OH)(TED)(0.5)]·1.5DMF·0.3H(2)O and [Zn(BDC-NH(2))(TED)(0.5)]·xDMF·yH(2)O show significant enhancement in CO(2) uptake at room temperature, suggesting that the strong interactions between CO(2) and the functionalized ligands, indicating that surface chemistry, rather than porosity, plays a more important role in CO(2) adsorption. A comparison of single-component CO(2), CH(4), CO, N(2), and O(2) adsorption isotherms demonstrates that the adsorption selectivity of CO(2) over other small gases is considerably enhanced through functionalization of the frameworks. Infrared absorption spectroscopic measurements and theoretical calculations are also carried out to assess the effect of functional groups on CO(2) and H(2) adsorption potentials.

Molecular hydrogen "pairing" interaction in a metal organic framework system with unsaturated metal centers (MOF-74).

Infrared (IR) absorption spectroscopy measurements of molecular hydrogen in MOF-74-M (M = metal center) are performed as a function of temperature and pressure [to 45 kTorr (60 bar) at 300 K, and at lower pressures in the 20-200 K range] to investigate the nature of H(2) interactions with the unsaturated metal centers. A small shift (∼ -30 cm(-1) with respect to the unperturbed H(2) molecule) is observed for the internal stretch frequency of H(2) molecules adsorbed on the metal site at low loading. This finding is in contrast to much larger shifts (∼ -70 cm(-1)) observed in previous studies of MOFs with unsaturated metal centers (including MOF-74) and the general assumption that H(2) stretch shifts depend on adsorption energies (FitzGerald et al., Phys. Rev. B 2010, 81, 104305). We show that larger shifts (∼ -70 cm(-1)) do occur, but only when the next available site ("oxygen" site) is occupied. This larger shift originates from H(2)-H(2) interactions on neighboring sites of the same pore, consistent with the short distance between H(2) in these two sites ∼2.6 Šderived from an analysis of neutron diffraction experiments of D(2)-D(2) at 4 K (Liu et al., Langmuir 2008, 24, 4772-4777). Our results at 77 K and low loading can be explained by a diffusion barrier against pair disruption, which should be enhanced by this interaction. Calculations indicate that the vibrational shifts do not correlate with binding energies and are instead very sensitive to the environment (interaction potential and H(2)-H(2) interactions), which complicates the use of variable temperature IR methods to calculate adsorption energies of specific adsorption sites.

Interaction of molecular hydrogen with microporous metal organic framework materials at room temperature.

Infrared (IR) absorption spectroscopy measurements, performed at 300 K and high pressures (27-55 bar) on several prototypes of metal organic framework (MOF) materials, reveal that the MOF ligands are weakly perturbed upon incorporation of guest molecules and that the molecular hydrogen (H(2)) stretch mode is red-shifted (30-40 cm(-1)) from its unperturbed value (4155 cm(-1) for ortho H(2)). For MOFs of the form M(bdc)(ted)(0.5) (bdc = 1,4-benzenedicarboxylate; ted = triethylenediamine), H(2) molecules interact with the organic ligands instead of the saturated metal centers located at the corners of the unit cell. First-principles van der Waals density functional calculations identify the binding sites and further show that the induced dipole associated with the trapped H(2) depends sensitively on these sites. For M(bdc)(ted)(0.5) systems, the strongest dipole moment is of the site that is in the corner of the unit cell and is dominated by the interaction with the benzene ligand and not by the metal center. For MOFs of the M(3)[HCOO](6) type with relatively short ligands (i.e., formate) and 1-D pore structures, there is a weak dependence of H(2) vibrational frequency on the cations, due to a small change in the unit cell dimension. Furthermore, translational states of approximately +/-100 cm(-1) are clearly observed as side bands on the H(2) stretch mode in these 1-D channels interconnected by very small apertures. The H(2) stretch IR integrated areas in all the MOFs considered in this work increase linearly with H(2) pressure, consistent with isotherm measurements performed in similar conditions. However, the IR intensity varies substantially, depending on the number of benzene rings interacting with the H(2) molecules. Finally, there is no correlation between H(2) binding energies (determined by isotherm measurements) and the magnitude of the H(2) stretch shift, indicating that IR shifts are dominated by the environment (organic ligand, metal center, and structure) rather than the strength of the interaction. These results highlight the relevance of IR spectroscopy to determine the type and arrangement of ligands in the structure of MOFs.

Energetics and dynamics of H(2) adsorbed in a nanoporous material at low temperature.

Molecular hydrogen adsorption in a nanoporous metal-organic framework structure (MOF-74) is studied via van der Waals density-functional calculations. The primary and secondary binding sites for H(2) are confirmed. The low-lying rotational and translational energy levels are calculated, based on the orientation and position dependent potential energy surface at the two binding sites. A consistent picture is obtained between the calculated rotational-translational transitions for different H(2) loadings and those measured by inelastic neutron scattering exciting the singlet to triplet (para to ortho) transition in H(2). The H(2) binding energy after zero-point energy correction due to the rotational and translational motions is predicted to be approximately 100 meV in good agreement with the experimental value of approximately 90 meV.

RPM3: a multifunctional microporous MOF with recyclable framework and high H2 binding energy.

A microporous metal organic framework structure, Zn(2)(bpdc)(2)(bpee).2DMF (DMF: N,N-dimethylformamide), has been synthesized via solvothermal reactions. The compound is a new member of the RPM series (RPM = Rutgers Recyclable Porous Material) that possesses a flexible and recyclable three-dimensional framework containing one-dimensional channels. It exhibits interesting and multifold functionality, including porosity, commensurate adsorption for hydrocarbons, high hydrogen binding energy (determined by isosteric heats of hydrogen adsorption and confirmed by van der Waals density functional calculations) as a result of multifold binding to aromatic ligands (determined by IR spectroscopy), strong photoluminescence emission, and reversible fluorescence quenching properties.

A density functional for sparse matter.

Sparse matter is abundant and has both strong local bonds and weak nonbonding forces, in particular nonlocal van der Waals (vdW) forces between atoms separated by empty space. It encompasses a broad spectrum of systems, like soft matter, adsorption systems and biostructures. Density-functional theory (DFT), long since proven successful for dense matter, seems now to have come to a point, where useful extensions to sparse matter are available. In particular, a functional form, vdW-DF (Dion et al 2004 Phys. Rev. Lett. 92 246401; Thonhauser et al 2007 Phys. Rev. B 76 125112), has been proposed for the nonlocal correlations between electrons and applied to various relevant molecules and materials, including to those layered systems like graphite, boron nitride and molybdenum sulfide, to dimers of benzene, polycyclic aromatic hydrocarbons (PAHs), doped benzene, cytosine and DNA base pairs, to nonbonding forces in molecules, to adsorbed molecules, like benzene, naphthalene, phenol and adenine on graphite, alumina and metals, to polymer and carbon nanotube (CNT) crystals, and hydrogen storage in graphite and metal-organic frameworks (MOFs), and to the structure of DNA and of DNA with intercalators. Comparison with results from wavefunction calculations for the smaller systems and with experimental data for the extended ones show the vdW-DF path to be promising. This could have great ramifications.