First-principles study of large-amplitude dynamic Jahn-Teller effects in vanadium tetrafluoride.

Transition metal tetrahalides are a class of highly symmetric molecules for which very few spectroscopic data exist. Exploratory ab initio calculations of electronic potential energy functions indicate that the equilibrium molecular geometries of the vanadium, niobium, and tantalum tetrafluorides (i.e., VF4, NbF4, and TaF4) exhibit strong distortions from the tetrahedral configuration in their electronic ground state (2E) and first excited state (2T2) along the nuclear displacement coordinates of e symmetry. The distortions result from the E × e and T2 × e Jahn-Teller (JT) effects, respectively. In addition, there are weaker distortions in the 2T2 state along the coordinates of t2 symmetry due to the T2 × t2 JT effect. The description of the large-amplitude dynamics induced by these JT effects requires the construction of JT Hamiltonians beyond the standard model of JT theory, which is based on Taylor expansions up to second order in normal-mode displacements. These higher-order JT Hamiltonians were constructed in this work by expansions of the electronic potentials of the title molecule in terms of symmetry invariant polynomials in symmetry-adapted nuclear displacement coordinates for the bending modes of VF4. A multi-configuration electronic structure method was employed to determine the coefficients of these high-order polynomial expansions from first principles. Using these large-amplitude Jahn-Teller Hamiltonians, the vibronic spectra of VF4 were computed. The spectra illustrate the effects of large-amplitude fluxional nonadiabatic dynamics due to exceptionally strong E × e and T2 × e JT couplings. In addition, the vibronic spectrum of the T2 × (e + t2) JT effect, including the bending mode of t2 symmetry, was computed. The spectrum displays strong inter-mode coupling effects exhibiting a vibronic structure, which is substantially different from that predicted by independent-mode approximation. These results represent the first ab initio study of dynamical Jahn-Teller effects in VF4.

Controlled intramolecular H-transfer in malonaldehyde in the electronic ground state mediated through the conical intersection of 1nπ* and 1ππ* excited electronic states.

We report photo-isomerization of malonaldehyde in its electronic ground state (S0), mediated by coupled 1nπ*(S1)-1ππ*(S2) excited electronic states, accomplished with the aid of optimally designed ultraviolet (UV)-laser pulses. In particular, control of H-transfer from a configuration predominantly located in the left well (say, reactant) to that in the right well (say, product) of the electronic ground S0 potential energy surface is achieved by a pump-dump mechanism including the nonadiabatic interactions between the excited S1 and S2 states. An interplay between the nonadiabatic coupling due to the conical intersection of the S1 and S2 states and the laser-molecule interaction is found to be imprinted in the time-dependent electronic population. The latter is also examined by employing optimal fields of varying intensities and frequencies of the UV laser pulses. For the purpose of the present study, we constructed a three-state and two-mode coupled diabatic Hamiltonian with the help of adiabatic electronic energies and transition dipole moments calculated by ab initio quantum chemistry methods. The electronic diabatic model is developed using the calculated adiabatic energies of the two excited electronic states (S1 and S2) in order to carry out the dynamics study. The optimal fields for achieving the controlled isomerization are designed within the framework of optimal control theory employing the optimization technique of a multitarget functional using the genetic algorithm. The laser-driven dynamics of the system is treated by numerically solving the time-dependent Schrödinger equation within the dipole approximation. A time-averaged yield of the target product of ∼40% is achieved in the present treatment of dynamics with optimal laser pulses.

An alternative laser driven photodissociation mechanism of pyrrole via πσ*1∕S0 conical intersection.

A first principles quantum dynamics study of N-H photodissociation of pyrrole on the S0-1πσ*(A21) coupled electronic states is carried out with the aid of an optimally designed UV-laser pulse. A new photodissociation path, as compared to the conventional barrier crossing on the πσ*1 state, opens up upon electronic transitions under the influence of pump-dump laser pulses, which efficiently populate both the dissociation channels. The interplay of electronic transitions due both to vibronic coupling and the laser pulse is observed in the control mechanism and discussed in detail. The proposed control mechanism seems to be robust, and not discussed in the literature so far, and is expected to trigger future experiments on the πσ*1 photochemistry of molecules of chemical and biological importance. The design of the optimal pulses and their application to enhance the overall dissociation probability is carried out within the framework of optimal control theory. The quantum dynamics of the system in the presence of pulse is treated by solving the time-dependent Schrödinger equation in the semi-classical dipole approximation.

Staged complex abdominal wall hernia repair in morbidly obese patients.

PURPOSE: The repair of complex abdominal wall hernias in morbidly obese patients is often associated with a higher risk of complications and hernia recurrences. Improvement in obesity and its associated metabolic complications are hypothesized to improve hernia repair outcomes. This study analyzes outcomes from morbidly obese patients who underwent bariatric surgery with staged complex abdominal wall reconstruction at Creighton University Medical Center (CUMC). METHODS: This retrospective study included morbidly obese patients with complex abdominal wall hernia, who underwent bariatric surgery with staged abdominal wall reconstruction. Data points collected included patient demographics, obesity-related co-morbidities, pre-operative BMI, EBMIL at 12 months, hernia characteristics, postoperative complications, BMI at time of hernia repair, and hernia recurrence. RESULTS: Twelve patients with an average BMI of 48 and complex abdominal wall hernias (mean width 14.0 cm) met inclusion criteria. Seven patients (58%) had significant loss of domain. Bariatric procedures included six laparoscopic sleeve gastrectomies (LSG), three laparoscopic Roux-en-Y gastric bypasses (LRNYGB), and three revisional procedures (2 vertical band gastroplasties to LRNYGB and 1 LRNYGB revision). At 12-month follow-up, the mean excess BMI loss (EBMIL) was 64.6%. The average time to staged complex abdominal wall reconstruction was 22.3 months. Two non-elective hernia repairs were performed due to one incarceration and one strangulation. There were no recurrences after an average follow-up of 21.9 months. CONCLUSIONS: In this study, staged mesh repair of complex abdominal wall hernias after bariatric surgery in morbidly obese patients was associated with acceptable morbidity and no hernia recurrences at approximately 1.5 year follow-up.

Early combination therapy: intracavernosal injections and sildenafil following radical prostatectomy increases sexual activity and the return of natural erections.

Early pharmacological prophylaxis has been reported to increase the return of spontaneous erections following radical prostatectomy (RP). In this study, we evaluated the role of intracavernosal alprostadil (PGE1) combined with sildenafil in stimulating early recovery of spontaneous erections following RP. In this prospective study, we included 22 patients who underwent bilateral nerve-sparing RP after October 2004. Sildenafil dose of 50 mg/day was started at the time of hospital discharge. Of 22 patients, 18 started on PGE1-4 microg (1-8) and four started on low-dose Trimix (20 U) 2-3 times/week. These patients are followed up at regular intervals (3, 6, 9 and 12 months) with abridged version of the International Index for Erectile Function-5 questionnaire. Patient compliance, return of sexual activity and return of natural erection, adverse effects and reasons for discontinuation were recorded. Penile doppler studies were performed during followup visits to assess the vascular status. After a mean followup of 6 months (3-8 months), 11/22 (50%) patients had return of spontaneous partial erections. Of the 18 PGE1 users, six continued 4 microg PGE1, four increased the dose to 8 microg, six decreased the dose to 2 microg and two patients further reduced the dose to 1 microg. Of four low-dose Trimix users, three increased the dose to 30 U and one reduced the dose to 15 U. Of 22 patients, 21 were sexually active: 12/21 (57%) with the injections alone and 9/21 (42.9%) with combination therapy (injections (PGE1) and sildenafil). Penile doppler studies revealed arterial insufficiency in 77% (17/22) patients and venous insufficiency in one patient. Early intracavernosal injections following RP facilitated early sexual intercourse, patient satisfaction and potentially earlier return of natural erections. Early combination therapy with sildenafil allowed a lower dose of intracavernous injections, minimizing the penile discomfort.

Sexual dysfunction after pelvic surgery.

Pelvic surgeries are among the most common causes of organic sexual dysfunction in men and women. The impact of nerve-sparing surgery on potency has been well documented in radical prostatectomy. However, its impact on potency needs to be evaluated in other pelvic surgeries. Sexual dysfunction is highly prevalent even after multiple technical advances in the field of oncological surgeries. The prevalence varies from 8 to 82%, depending on the type of pelvic surgery. In females, sexual dysfunction has not been evaluated adequately using validated questionnaires. However, in subspecialized circles, treatment for female sexual dysfunction is becoming routine. Currently, physicians have several options for the treatment of erectile dysfunction (ED) in men. Since the introduction of oral PDE-5 inhibitors, oral therapy has become the first-line treatment option for ED, irrespective of etiology. Currently available treatment options for the female sexual dysfunction include estrogens, androgens, phosphodiesterase inhibitors, and dopamine receptor antagonists. Initial reports regarding the role of early rehabilitation are encouraging and may become the part of routine practice in the management of ED after pelvic surgery. In this article, we summarize the sexual dysfunction following pelvic surgeries and their management.

Early use of vacuum constriction device following radical prostatectomy facilitates early sexual activity and potentially earlier return of erectile function.

To assess the efficacy of vacuum constriction devices (VCD) following radical prostatectomy (RP) and determine whether early use of VCD facilitates early sexual activity and potentially earlier return of erectile function. This prospective study consisted of 109 patients who underwent nerve-sparing (NS) or non-nerve-sparing (NNS) RP between August 1999 and October 2001 and developed erectile dysfunction following surgery. The patients were randomized to VCD use daily for 9 months (Group 1, N=74) or observation without any erectogenic treatment (Group 2, N=35). Treatment efficacy was analyzed by responses to the Sexual Health Inventory of Men (SHIM) (abridged 5-item International Index of Erectile Function (IIEF-5)), which were stratified by the NS status. Patient outcome regarding compliance, change in penile length, return of natural erection, and ability for vaginal intercourse were also assessed. The mean patient age was 58.2 years, and the minimum follow-up was 9 months. Use of VCD began at an average of 3.9 weeks after RP. In Group 1, 80% (60/74) successfully used their VCD with a constriction ring for vaginal intercourse at a frequency of twice/week with an overall spousal satisfaction rate of 55% (33/60). In all, 19 of these 60 patients (32%) reported return of natural erections at 9 months, with 10/60 (17%) having erections sufficient for vaginal intercourse. The abridged IIEF-5 score significantly increased after VCD use in both the NS and NNS groups. After a mean use of 3 months, 14/74 (18%) discontinued treatment. In Group 2, 37% (13/35) of patients regained spontaneous erections at a minimum follow-up of 9 months after surgery. However, only four of these patients (29%) had erections sufficient for successful vaginal intercourse and rest of patients (71%) sought adjuvant treatment. Of the 60 successful users, 14 (23%) reported a decrease in penile length and circumference at 9 months (range, 4-8 months) compared to 12/14 (85%) among the nonresponders. However, in control group 22/35 reported decrease in penile length and circumference. Early use of VCD following RP facilitates early sexual intercourse, early patient/spousal sexual satisfaction, and potentially an earlier return of natural erections sufficient for vaginal penetration.

Free hernia surgery for the underserved is possible in the United States.

INTRODUCTION: Inguinal hernia is one of the most common ailments known to mankind. When symptomatic it can severely affect the patient's quality of life. Nevertheless, the vast majority of inguinal herniorrhaphies are elective and, therefore, not available to uninsured patients who do not have the financial wherewithal to pay for the operation. Using the Surgery on Sunday model developed in Kentucky, hernia repair for the underserved developed a free clinic for hernia surgery, based on institutional commitment to the poor as well as the volunteer efforts of medical students and hospital personnel at all levels. METHODS: After consulting with Surgery on Sunday personnel, HRFU determined the number of in need patients by consulting with local free clinic physicians. Second, and most time consuming, was the application for the Federal Tort Claims Act (FTCA) medical legal protection. Under this law, all in hospital credentialed volunteer professionals are medico-legally protected if the surgery is performed in an associated free clinic. After FTCA application re-writes and committee meetings to work out logistics of the pre-op clinic, the follow-up clinic, enlistment of other volunteers such as transporters, translators, housekeeping for the ORs, a pharmacist, registration personnel and creation of HRFU hospital forms we established a surgery date. A memorandum of understanding was drafted and an agreement letter with the hospital system was co-signed. Fourteen patients were seen in the pre-operative clinic and two were placed on waiting list. Patients were operated upon using 3 operating rooms and a volunteer staff of 4 surgeons, 4 anesthesia personnel and 13 nurses. RESULTS: No surgical complications were encountered intra-operatively or in the recovery room, and all patients were discharged by 2:30 p.m. 1 week post-operatively one patient had severe incisional pain, two had operative site swelling, but there was no evidence of infection or hematoma, and one had a distal sac fluid collection. All patients returned for follow-up and were appreciative of the care provided. The enthusiasm and participation of the patients and staff both pre-operatively, the day of surgery and postoperatively was outstanding. CONCLUSION: On the basis of this result HRFU is prepared to assist other US hernia specialists and their respective hospitals to make Surgery on Sunday a possibility in their community.

Relationship of interleukin-6 with semen characteristics and oxidative stress in vasectomy reversal patients.

This prospective study was performed to evaluate the relationship between interleukin-6 (IL-6), oxidative stress and sperm function following vasectomy reversal. We included 22 patients who underwent vasectomy reversal and 15 healthy sperm donors (controls) with normal sperm morphology criteria. Levels of IL-6 in the semen were measured by the enzyme-linked immunosorbent assay, and levels of reactive oxygen species (ROS) and total antioxidant capacity were measured by the chemiluminescence assay. The mean sperm concentration in the vasectomy reversal group was significantly lower than control group (45.3 +/- 39.1 versus 63.1 +/- 28.5; P = 0.02). Motility was also significantly lower in the vasectomy reversal group (32.1 +/- 19.9 versus 54.6 +/- 18.9; P = 001). Levels of IL-6 were significantly higher in the vasectomy reversal group (2.09 +/- 0.87 versus 0.99 +/- 0.97; P = 0.007) as were mean ROS levels (2.25 +/- 0.97 versus 1.2 +/- 0.7; P = 0.009). Significant positive correlation was observed between the IL-6 and ROS levels in vasectomy reversal patients compared with donors (r = 0.41, P = 0.05 versus r = 0.38, P = 0.15). We conclude that patients who undergo vasectomy reversal have elevated levels of IL-6 and ROS, which may contribute to decreased sperm motility and concentration and possibly lead to sub-fertility.