Multi-dimensional steric effect for XeI* (B) formation in the oriented Xe* ((3)P(2), M(J) = 2) + oriented CH(3)I reaction

Multi-dimensional steric effect for the XeI* (B) formation in the oriented Xe* ((3)P(2), M(J) = 2) + oriented CH(3)I reaction has been observed as a function of the mutual configuration between the molecular orientation and the atomic alignment in the collision frame. The molecular steric opacity function has been determined as a function of the atomic orbital alignment. The large molecular orientation dependence (i.e., the largest reactivity at the I-end and the large difference in the reaction probability between the I-end and the CH(3)-end) and the large molecular alignment dependence (the poor reactivity at the sideway) is recognized for each atomic orbital alignment. In addition, a clear correlation between the molecular orientation and the atomic orbital alignment is recognized (i.e., the L(Z)' = 0 atomic orbital alignment is favorable for the molecular axis direction, while the |L(Z)'| = 1 atomic orbital alignment is favorable for the sideway direction).

Multidimensional steric effect for the XeBr* (B, C) formation in the oriented Xe*((3)P2, M(J) = 2) + oriented CF3Br reaction

Steric effect for the XeBr(*) (B, C) formation in the oriented Xe(*)((3)P(2), M(J) = 2) + oriented CF(3)Br reaction has been observed as a function of the mutual configuration between the molecular orientation and the atomic orientation in the collision frame. Molecular steric opacity function has been determined as a function of the atomic orbital alignment (L(Z)(')) in the collision frame. The L(Z)(') selectivity in the molecular steric opacity function is different between the XeBr(*) (B, C) channels: For the XeBr(*) (C) channel, the L(Z)(') = 0 alignment is favorable at the molecular axis direction and the absolute value(L(Z)(')) = 1 alignment is favorable at the sideway direction, whereas for the XeBr(*) (B) channel, the L(Z)(') = 0 alignment is favorable at the sideway direction and the absolute value(L(Z)(')) = 1 alignment is favorable at the molecular axis direction. However, the shape of the steric opacity function for the XeBr(*) (B) channel at the L(Z)(') = 0 (and absolute value(L(Z)(')) = 1) alignment is similar to that for the XeBr(*) (C) channel at the absolute value(L(Z)(')) = 1 (and L(Z)(') = 0) alignment, respectively: A large molecular orientation dependence (i.e., the largest reactivity at the Br-end with the small molecular alignment dependence) is recognized for the XeBr(*) (B) channel at the L(Z)(') = 0 alignment and for the XeBr(*) (C) channel at the absolute value(L(Z)(')) = 1 alignment, whereas a large molecular alignment dependence (i.e., the largest reactivity at the Br-end with the poor reactivity at the sideway) is recognized for the XeBr(*) (B) channel at the absolute value(L(Z)(')) = 1 alignment and for the XeBr(*) (C) channel at the L(Z)(') = 0 alignment. We propose the indirect mechanism for the dark channels (Xe + Br + CF(3)) via the back-electron transfer from the CF(3) segment (or dissociating CF(3)...Br(-)) to Xe(+) as the origin of the significant molecular alignment dependence in the molecular steric opacity function.

Atomic alignment effects for the formation of excimers RgX* (B, C) in the reaction of oriented Rg ((3)P2, M(J) = 2) (Rg = Xe, Kr, Ar) + halogen(X)-containing molecules

Atomic alignment effects for the formation of excimers, RgX* (B, Omega = 1/2) and RgX* (C, Omega = 3/2), in the reaction of Rg ((3)P(2)) (Rg = Xe, Kr, Ar) with halogen (X)-containing molecules (RX) (CH(3)I, CF(3)I, CF(3)Br, NF(3), CHBr(3), CHCl(3), CCl(3)F, and CCl(4)) have been measured by using an oriented Rg ((3)P(2), M(J) = 2) atomic beam at a collision energy of approximately 0.07 eV. The emission intensities for RgX* (B, C) have been measured as a function of the magnetic orientation field direction in the collision frame. The reactant (RX) dependence of the atomic alignment effect is extremely different between the RgX* (B) and the RgX* (C) channels. For RgX* (C), an analogous atomic alignment effect is commonly observed despite the difference of RX and Rg. In contrast, for RgX* (B), the atomic alignment effect shows a diverse dependence on RX and Rg.

Steric effect in the energy transfer reaction of oriented Kr (3P2, MJ = 2) + CO

Atomic alignment effect for the formations of CO (a' (3)Sigma(+)) and CO (d (3)Delta) in the energy transfer reaction of oriented Kr ((3)P(2), M(J) = 2) + CO has been measured at a collision energy of 0.07 eV. The emission intensities of CO (a' (3)Sigma(+)) and CO (d (3)Delta) were similarly highly enhanced when the electron angular momentum of Kr ((3)P(2)) is aligned perpendicular to the relative velocity vector. We observed the analogous atomic alignment effect between the CO (a' (3)Sigma(+)) and CO (d (3)Delta) formations. That is, the |M(J)'| = 2 magnetic substate in the collision frame is significantly less reactive than the other M(J)' states. In addition, the large difference of the cross section (sigma(Sigma)/sigma(Pi) approximately 2.0) between the Sigma- and Pi-configuration of the unpaired 4p orbital of Kr ((3)P(2)) is recognized.

Collision energy dependence of the rotational-state-resolved cross section in the CH (v = 0, J, F(i)) + O(2) --> OH(A) + CO reaction

A velocity variable rotational-state-selected CH (v = 0, J, F(i)) beam has been prepared by using an electric hexapole and applied to the CH (v = 0, J, F(i)) + O(2) --> OH(A) + CO reaction. The CH rotational-state-resolved reaction cross sections have been determined under the beam-cell condition at the collision energy range of 0.06-0.18 eV. The N = 2 rotational states are 2-3 times more reactive than the other states (N = 1, 3). In addition, we observed a noticeable difference in the collision energy dependence of the cross section between the CH rotational states. The reaction cross section for the N = 2 states has a gentle negative dependence on collision energy, while, the reaction cross section for the N = 1 states has a positive dependence on collision energy.

The Culdotomy FourS Two U procedure for transvaginal access to the peritoneal cavity

A reliable method of transvaginal access is needed for natural orifice transluminal endoscopic surgery. We introduce a new culdotomy procedure, using a technique for the creation of space in the cul-de-sac, transvaginal ultrasound, and a newly developed umbrella Hakko needle. An artificially developed, saline-containing space in the cul-de-sac was punctured by an umbrella Hakko needle from the vagina under the guidance of ultrasound. The vaginal walls on both sides of the needle were incised with an electric scalpel. In five cases with benign gynecological tumors, culdotomy was successfully performed. Operating time was less than 10 minutes and blood loss was less than 10 mL. There were no culdotomy-associated complications. This procedure, named Culdotomy FourS Two U, is a simple, safe, and reliable method for entry into the cul-de-sac in transvaginal gynecological surgeries and may have future applications in transluminal endoscopic surgery through the vagina.

Long-time exposure of mouse embryos to the sperm produces high levels of reactive oxygen species in culture medium and relates to poor embryo development

Small amounts of reactive oxygen species (ROS), metabolites of oxygen, are necessary for sperm-fertilizing capability. However, in excessive levels, their role in infertility has been extensively studied. The conventional in vitro fertilization (IVF) method employs a prolonged co-incubation of gametes for 16-18 h to reach fertilization. However, it has been shown that this long period might create high levels of ROS. We aimed at finding out whether ROS increases in vitro during prolonged incubation with fertilized oocytes and whether high level of ROS relates to poor embryo development. To confirm if levels of ROS relate to length of time, we measured the ROS levels in fertilization medium (FM), which contained mouse embryos exposed to spermatozoa. To evaluate the contribution of sperm in production of ROS, we measured the ROS in the medium with only sperm. The measurements were performed by chemiluminescence assay using luminol as a probe after 4 and 18 h of incubation separately. The ROS levels were significantly increased after 18 h as compared with 4 h (p < 0.0001). Moreover, ROS in the medium with only sperm was also increased after 18 h (p < 0.0001), demonstrating that they were generated either by spermatozoa or as a result of possible reaction of sperm with medium during prolonged incubation. In addition, we compared embryo development after 2, 4, 6, 8, 10, 12 and 18 h of incubation. The number of degenerated embryos exposed to sperm for 12 and 18 h was significantly higher than those exposed for 4 or 6 h (p < 0.01). These results demonstrate that ROS concentrations appear to be related to the length of incubation time, and their excessive levels have a negative effect on embryo development. We suggest reducing incubation time to at least 4 h.

Steric effect in the energy transfer reaction of N2 + Rg (3P2) (Rg = Kr, Ar)

Steric effect for the formation of N 2 (B, (3)Pi u ) in the energy transfer reaction of Kr ( (3)P 2) + N 2 has been measured using an oriented Kr ( (3)P 2, M J = 2) beam at a collision energy of 0.07 eV. The N 2 (B, (3)Pi u ) emission intensity was measured as a function of the magnetic orientation field direction in the collision frame. A significant atomic alignment effect on the energy transfer probability was observed. This result was compared with that for the formation of N 2 (C, (3)Pi g ) in the Ar ( (3)P 2) + N 2 reaction. Despite the large difference on the energy transfer cross-section, the atomic alignment dependence for Kr ( (3)P 2) + N 2 is found to be analogous to that for Ar ( (3)P 2) + N 2. It is revealed that the configuration of inner 4p (3p) orbital in the collision frame gives an important role for the stereoselectivity on electron transfer process via the curve-crossing mechanism.

Stereodynamics in dissociative adsorption of NO on Si(111)

We report results of our study on the surface-temperature dependence of the steric effect in the dissociative adsorption of NO on Si(111)-(7x7). Data presented here show that, at an incident energy of 58 meV, the reactive sticking probability for the N-end collision is larger than that for the O-end collision. Furthermore, this steric preference is quite sensitive to the surface temperature and the surface coverage. This study shows that the transient surface trapping into a shallow precursor well plays a key role in the stereodynamics of the dissociative adsorption at the low energy region.

Ultrasound-guided culdotomy for vaginal ovarian cystectomy using a renal balloon dilator catheter

OBJECTIVES

To evaluate the feasibility and utility of performing ultrasound-guided culdotomy using a renal balloon dilator catheter for transvaginal ovarian cystectomies.

METHODS

Culdotomy using transvaginal sonography and a Nephromax balloon dilator catheter was performed in 16 patients for the vaginal removal of benign ovarian cysts located in the cul-de-sac. Each ovarian cyst was punctured under transvaginal ultrasound guidance and the punctured site on the vaginal wall was enlarged with a dilator. The cyst was then enucleated through this vaginal wound. Preoperative characteristics of the patients, outcome, operating time, blood loss and complications of each culdotomy, and the histology of the cysts, were recorded and examined.

RESULTS

We used this method on 14 patients with unilateral ovarian cysts and two with bilateral cysts. Culdotomy was performed successfully in 15 cases (94%). The mean +/- SD operating time for culdotomy was 22 +/- 11 min, and blood loss during the procedure was less than 10 mL in all cases. There were no complications including rectal injury or febrile morbidity.

CONCLUSIONS

Culdotomy assisted by ultrasound imaging and a dilator is a safe, reliable and effective method for removal of benign ovarian cysts via a vaginal approach.

Effect of molecular rotation on the atomic alignment dependence in the oriented Ar (3P2) + CF3H reaction

Atomic alignment effect for the CF3* formation in the oriented Ar (3P2, MJ = 2) + CF3H reaction has been investigated at different two CF3H beam conditions: effusive and supersonic beams. The chemiluminescence intensity of CF3* was measured as a function of the magnetic orientation field direction in the collision frame. A significant contribution of rank 4 moment was recognized. The cross-section for each magnetic M'(J) substate in the collision frame, sigma|M'(J)|, was determined to be sigma(|M'(J)|=0):sigma(|M'(J)|=1):sigma(|M'(J)|=2) = 1.00:0.84 +/- 0.02:0.88 +/- 0.02 for the effusive CF3H beam condition. The atomic alignment effect was found to significantly depend on the CF3H beam condition. For the supersonic beam condition, sigma(|M'(J)|=0&1) was changed to be smaller than sigma(|M'(J)|=2).

Deuterium isotope effect on the atomic alignment dependence in the reaction of oriented Ar (3P2) with (CH3CN)2 and (CD3CN)2 dimers

The effect of atomic alignment on CN (B2Sigma+) formation has been studied in the reaction of oriented Ar (3P2) with (CX3CN)2 (X = H, D). The reaction cross-section for each magnetic M'(J) substate in the collision frame sigma|M'(J)|(H(D),d) relative to the cross-section sigma0(H,m) in the CH(3)CN reaction was determined to be sigma0(H,d)/sigma|1|(H,d)/sigma|2|(H,d)/sigma0(D,d)/sigma|1|(D,d):/sigma|2|(D,d)= 0.87/1.00/0.98/1.58/1.93/1.78. A notable deuterium isotope effect was observed. In contrast with the monomer reactions, a significant decrease of sigma0(H(D),d) relative to the other cross-sections of sigma|M'(J)|(H(D),d) was observed.