The effect of collisions on the rotational angular momentum of diatomic molecules studied using polarized light.

We report results of an experimental study of the changes in the alignment of the rotational angular momentum of diatomic molecules during elastic collisions. The experiment involved collisions of diatomic lithium molecules in the A1Σu + excited electronic state with noble gas atoms (helium and argon) in a thermal gas phase sample. Polarized light for excitation was combined with the detection of polarization-specific fluorescence in order to achieve magnetic sublevel state selectivity. We also report results for rotationally inelastic collisions of Li2 in the lowest lying rotational levels of the A1Σu +v=5 vibrational state with noble gas atoms.

Clomiphene citrate before and after withdrawal bleeding for induction of ovulation in women with polycystic ovary syndrome: Randomized cross-over trial.

AIM: To compare the ovarian response to early versus late clomiphene citrate (CC) in women with polycystic ovary syndrome (PCOS). METHODS: This cross-over randomized controlled clinical trial included 90 infertile amenorrheic women with PCOS. After inducing withdrawal bleeding, patients were randomly divided into two equal groups to receive ovulation induction with CC 100 mg/day for 5 days. Group I started treatment the next day after finishing medroxyprogesterone acetate course for a menstrual cycle, and after a washout period of another menstrual cycle, the treatment was shifted to start on day 2 of withdrawal bleeding. Group II received a reversed protocol: late then early treatment. Women were followed up on transvaginal ultrasonography to monitor follicular growth, endometrial thickness and evidence of ovulation. Human chorionic gonadotropin 10 000 IU was given i.m. to trigger ovulation when at least one mature follicle measured ≥18 mm at day 14. RESULTS: In all cases, early induction protocol resulted in significantly higher proportion of ovulating patients, thicker endometrium and higher number of follicles 14-17 mm in diameter, ≥ 18 mm in diameter and total number of follicles (P < 0.001 for all comparisons). CONCLUSION: In women with PCOS, early initiation of CC before withdrawal bleeding or during the last days of the luteal phase can achieve a better ovulatory response.

Diathermy versus scalpel in transverse abdominal incision in women undergoing repeated cesarean section: A randomized controlled trial.

AIM: The aim of this study was to evaluate the volume of blood loss, wound incision time and wound complication according to use of scalpel or electrosurgery during the creation of transverse abdominal incisions during repeated cesarean section (CS). MATERIAL AND METHODS: A randomized controlled trial was carried out at Ain Shams University Maternity Hospital. We recruited 130 women with a history of one previous CS at the time of their planned lower-segment CS. Participants were randomized to anterior abdominal wall opening from subcutaneous tissue till the peritoneum by either the use of scalpel with disposable blade (No. 22) or diathermy using the standard diathermy pen electrode. The main outcome measures were the volume of blood loss from skin incision to the end of the peritoneal incision, the operative time and wound complication. RESULTS: We observed a highly significant difference between the two groups in blood loss (median [interquartile range], 11 [8-15.25] g for the diathermy group vs 20 [18-23] g for the scalpel group, P < 0.001) and skin-to-peritoneum incision time (median [interquartile range], 7 [5-7.25] min for the diathermy group vs 10 [7-11] min for the scalpel group, P < 0.001). The postoperative pain was less in the diathermy group but wound complications showed no statistical difference. CONCLUSION: The use of diathermy in the opening of anterior abdominal wall during CS decreases blood loss and operative time but has no impact on postoperative pain or wound complications.

Intravenous infusion of paracetamol for intrapartum analgesia.

AIM: To evaluate the efficacy and adverse effects of an i.v. infusion of paracetamol during the active phase of labor as compared with sterile water (placebo) as a method for intrapartum analgesia. METHODS: In a triple-blind, randomized, placebo-controlled trial, 120 low-risk primiparous women presenting in active labor at Ain Shams University Maternity Hospital, Cairo, Egypt, between August 2011 and October 2012, were allocated to receive either 1000 mg i.v. of paracetamol (n = 60) or sterile water (n = 60). The primary outcomes were the efficacy of the drug to supply adequate analgesia as measured by a change in the visual analog scale (VAS) pain intensity score at various time points after drug administration and the need for additional rescue analgesia. The secondary outcomes included the presence of adverse maternal or fetal events. RESULTS: Compared to controls, i.v. infusion of paracetamol was associated with significantly lower VAS score 15 and 30 min after the start of medication; also, there was a significantly lower incidence of need for rescue medication (8/57 [14%] vs 49/59 [83.1%], P < 0.001) at 60 min after the start of medication. There were no recorded maternal adverse effects in either group. There were no differences in occurrence of intrapartum fetal distress or neonatal Apgar scores between both groups. CONCLUSION: Paracetamol appears to be a safe and effective medicine that can be used during the intrapartum period.

Updated potential energy function of the Rb2 a(3)Σu(+) state in the attractive and repulsive regions determined from its joint analysis with the 2(3)Π0g state.

We report new experimental data for the Rb2 a(3)Σu(+) and 2(3)Π0g states obtained using the Perturbation Facilitated Infrared-Infrared Double Resonance (PFIIDR) technique. The results include ro-vibrational term values of the 2(3)Π0g state and resolved fluorescence spectra of the 2(3)Π0g→a(3)Σu(+) transitions for a wide range of rotational and vibrational quantum numbers. An analysis of these data confirms the initial assignment of the transitions to the a(3)Σu(+) state reported in our earlier work [B. Beser, V. B. Sovkov, J. Bai, E. H. Ahmed, C. C. Tsai, F. Xie, L. Li, V. S. Ivanov, and A. M. Lyyra, J. Chem. Phys. 131, 094505 (2009)]. The potential energy functions of the Rb2 a(3)Σu(+) and 2(3)Π0g states are derived from a simultaneous fit of the available experimental data. The improved potential function of the Rb2 a(3)Σu(+) state spans both the attractive and repulsive regions starting with internuclear distance R ∼ 4.5 Å.

Quantum control of the spin-orbit interaction using the Autler-Townes effect.

We have demonstrated quantum control of the spin-orbit interaction based on the Autler-Townes (ac-Stark) effect in a molecular system using a cw optical field. We show that the enhancement of the spin-orbit interaction between a pair of weakly interacting singlet-triplet rovibrational levels, G (1)Π(g)(v=12,J=21,f)-1 (3)Σ(g)(-)(v=1,N=21,f), separated by 750 MHz in the lithium dimer, depends on the Rabi frequency (laser power) of the control laser. The increase in the spin-orbit interaction due to the control field is observed as a change in the spin character of the individual components of the perturbed pair.

Collisional transfer of population and orientation in NaK.

Collisional satellite lines with |ΔJ| ≤ 58 have been identified in recent polarization spectroscopy V-type optical-optical double resonance (OODR) excitation spectra of the Rb(2) molecule [H. Salami et al., Phys. Rev. A 80, 022515 (2009)]. Observation of these satellite lines clearly requires a transfer of population from the rotational level directly excited by the pump laser to a neighboring level in a collision of the molecule with an atomic perturber. However to be observed in polarization spectroscopy, the collision must also partially preserve the angular momentum orientation, which is at least somewhat surprising given the extremely large values of ΔJ that were observed. In the present work, we used the two-step OODR fluorescence and polarization spectroscopy techniques to obtain quantitative information on the transfer of population and orientation in rotationally inelastic collisions of the NaK molecules prepared in the 2(A)(1)Σ(+)(v' = 16, J' = 30) rovibrational level with argon and potassium perturbers. A rate equation model was used to study the intensities of these satellite lines as a function of argon pressure and heat pipe oven temperature, in order to separate the collisional effects of argon and potassium atoms. Using a fit of this rate equation model to the data, we found that collisions of NaK molecules with potassium atoms are more likely to transfer population and destroy orientation than collisions with argon atoms. Collisions with argon atoms show a strong propensity for population transfer with ΔJ = even. Conversely, collisions with potassium atoms do not show this ΔJ = even propensity, but do show a propensity for ΔJ = positive compared to ΔJ = negative, for this particular initial state. The density matrix equations of motion have also been solved numerically in order to test the approximations used in the rate equation model and to calculate fluorescence and polarization spectroscopy line shapes. In addition, we have measured rate coefficients for broadening of NaK 3(1)Π â† 2(A)(1)Σ(+)spectral lines due to collisions with argon and potassium atoms. Additional broadening, due to velocity changes occurring in rotationally inelastic collisions, has also been observed.

Experimental investigation of the 85Rb2 a 3Sigma(u)+ triplet ground state: multiparameter Morse long range potential analysis.

Using perturbation facilitated infrared-infrared double resonance excitation of the (85)Rb(2) molecule, we have observed spectrally resolved fluorescence to the a (3)Sigma(u)(+) state. We have analyzed the rovibrational energy level structure of the (85)Rb(2) a (3)Sigma(u)(+) state and derived a multiparameter Morse Long Range (MLR) potential and molecular constants for this state, which can be used to predict term values without needing to solve the radial Schrödinger equation.

Possible role of garlic oil in ameliorating renal injury after liver ischemia/reperfusion in rats.

Acute liver failure induces renal injury by triggering inflammation and oxidative stress. The heme oxygenase system has a preventive role against reperfusion injury, while garlic oil has antioxidants and anti-inflammatory effects. This study investigated the protective effects of garlic oil pretreatment on remote renal functions after liver ischemia/reperfusion (I/R), and clarifying gene expressions of heme oxygenase 1 (HO1), autophagy-related 7 (Atg7) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) in renal tissues. Thirty six adult female Wistar rats were randomly divided into control, garlic oil-supplemented, liver I/R, and garlic oil-pretreated liver I/R groups. Liver ischemia was performed in anesthetized rats for 45 min, followed by reperfusion for 24 hours in metabolic cages. Serum samples were used for determination of liver enzymes and creatinine levels and total antioxidant capacity (TAC). Urine samples were assayed for albumin, volume and creatinine concentration. Right liver lobe and right kidney specimens were used for determination of oxidative stress markers (colorimeterically). Also, gene expressions of HO1, Atg7 and PGC1α were investigated in right kidney specimens using real time PCR. Left kidney specimens were used for histopathological studies. Liver I/R group exhibited higher liver enzymes and creatinine levels in serum, prominent oxidative stress in both liver and renal tissues, albuminuria, lowered GFR deranged renal structure, and upregulated HO1, Atg7 and PGC1α gene expressions in renal tissues. Garlic oil-pretreated I/R group restricted such detrimental changes in renal functions and structure, though it caused further upregulation of the studied gene expression in renal tissue to alleviate the oxidative stress. It is concluded that garlic oil exerted reno-protective effected against remote organ damage induced by liver I/R injury, through enhancing HO1, Atg7 and PGC1α gene expressions.

Measurement of absolute transition dipole moment functions of the 3 (1)Pi --> 1(X) (1)Sigma+ and 3 (1)Pi --> 2(A) (1)Sigma+ transitions in NaK using Autler-Townes spectroscopy and calibrated fluorescence.

We describe a two-laser experiment using optical-optical double resonance fluorescence and Autler-Townes (AT) splittings to determine the NaK 3 (1)Pi-->1(X)(1)Sigma(+), 2(A)(1)Sigma(+) absolute transition dipole moment functions. Resolved 3 (1)Pi-->A (1)Sigma(+) and 3 (1)Pi-->X (1)Sigma(+) fluorescence was recorded with the frequencies of a titanium-sapphire laser (L1) and a ring dye laser (L2) fixed to excite particular 3 (1)Pi(upsilon = 19,J = 11,f)<--A (1)Sigma(+)(upsilon('),J(') = J = 11,e)<--X (1)Sigma(+)(upsilon("),J(") = J(')+/-1,e) double resonance transitions. The coefficients of a trial transition dipole moment function mu(e)(R) = a(0)+a(1)(R(eq)/R)(2)+a(2)(R(eq)/R)(4)+... were adjusted to match the relative intensities of resolved spectral lines terminating on the lower A (1)Sigma(+)(upsilon('),11,e) and X (1)Sigma(+)(upsilon("),11,e) levels. These data provide a relative measure of the functions mu(e)(R) over a broad range of R. Next, L2 was tuned to either the 3 (1)Pi(19,11,f)<--A (1)Sigma(+)(10,11,e) or 3 (1)Pi(19,11,f)<--A (1)Sigma(+)(9,11,e) transition and focused to an intensity large enough to split the levels via the AT effect. L1 was scanned over the A (1)Sigma(+)(10,11,e)<--X (1)Sigma(+)(1,10,e) or A (1)Sigma(+)(9,11,e)<--X (1)Sigma(+)(0,12,e) transition to probe the AT line shape, which was fit using density matrix equations to yield an absolute value for mu(ik) = integral psi(vib) (i)(R)mu(e)(R)psi(vib)(k)(R)dR, where i and k represent the upper and lower levels, respectively, of the coupling laser (L2) transition. Finally, the values of mu(ik) were used to place the relative mu(e)(R) functions obtained with resolved fluorescence onto an absolute scale. We compare our experimental transition dipole moment functions to the theoretical work of Magnier et al. [J. Mol. Spectrosc. 200, 96 (2000)].

Comparison of Autler-Townes splitting based absolute measurements of the (7)Li(2) A (1)Sigma(u) (+)-X (1)Sigma(g) (+) electronic transition dipole moment with ab initio theory.

We report a comparison between experimental and theoretical electronic transition dipole moment values for the (7)Li(2) A (1)Sigma(u) (+)-X (1)Sigma(g) (+) system. The experimental results are based on measuring the absolute magnitude of the transition dipole matrix elements from Autler-Townes splitting of rovibrational transitions for different R-centroid values. The ab initio theoretical calculations of the transition dipole moment for the (7)Li(2) A (1)Sigma(u) (+)-X (1)Sigma(g) (+) system were performed using two different quantum-mechanical models: an all-electron valence bond self-consistent-field method and a pseudopotential molecular orbital method. As expected for the smallest molecule with core electrons, the agreement between experiment and theory is very good.

Randomized controlled trial comparing carbetocin, misoprostol, and oxytocin for the prevention of postpartum hemorrhage following an elective cesarean delivery.

OBJECTIVE: To compare the effectiveness and safety of carbetocin, misoprostol, and oxytocin for the prevention of postpartum hemorrhage following cesarean deliveries. METHODS: A double-blind randomized controlled trial enrolled patients with a singleton pregnancy scheduled for an elective cesarean delivery at a maternity hospital in Cairo, Egypt, between October 1, 2012 and June 30, 2013. Participants were randomized using a computer-generated sequence to receive treatment with carbetocin, misoprostol, or oxytocin. The primary outcome was the occurrence of uterine atony necessitating additional uterotonics. Per-protocol analyses were performed. Patients, investigators, and data analysts were masked to treatment assignments. RESULTS: The present study enrolled 263 patients; data were analyzed from 88 patients treated with carbetocin, 89 treated with misoprostol, and 86 women treated with oxytocin. Further uterotonics were needed for the treatment of 5 (6%) patients who were treated with carbetocin, 20 (22%) patients treated with misoprostol, and 11 (13%) patients treated with oxytocin. In the prevention of uterine atony, carbetocin was comparable with oxytocin (RR 0.41, 95%CI 0.14-1.25) and superior to misoprostol (RR 0.21, 95%CI 0.07-0.58). CONCLUSION: Additional uterotonics were needed less frequently by patients treated with carbetocin. Carbetocin was comparable to oxytocin and superior to misoprostol in the prevention of uterine atony following an elective cesarean delivery. ClinicalTrials.gov: NCT02053922.

Intravenous infusion of paracetamol versus intravenous pethidine as an intrapartum analgesic in the first stage of labor.

OBJECTIVE: To evaluate the efficacy and adverse effects of an intravenous infusion of 1000 mg of paracetamol as compared with an intravenous injection of 50mg of pethidine hydrochloride for intrapartum analgesia. METHODS: In a randomized prospective study at Ain Shams University, Cairo, Egypt, between April and August 2010, 102 low-risk primiparous women in active labor were allocated to received either paracetamol (n=52) or pethidine hydrochloride (n=50). The primary outcome was the efficacy of the drug to supply adequate analgesia as measured by a change in the visual analog scale (VAS) pain intensity score at various times after drug administration. The secondary outcomes included the need for additional rescue analgesia and the presence of adverse maternal or fetal events. RESULTS: As recorded by the VAS score, there was significant pain reduction at 15 minutes, and at 1 and 2 hours in both groups (P<0.001). The reduction in pain was significantly greater in the pethidine group only at 15 minutes (P=0.004). None of the women in the paracetamol group had adverse effects, as compared with 64% of the women receiving pethidine. CONCLUSION: The effectiveness of intravenous paracetamol was comparable to that of intravenous pethidine, but paracetamol had fewer maternal adverse effects.