FT-IR, FT-Raman, NMR and UV-vis spectra, vibrational assignments and DFT calculations of 4-butyl benzoic acid

The solid phase FTIR and FT-Raman spectra of 4-butyl benzoic acid (4-BBA) have been recorded in the regions 400-4000 and 50-4000cm(-1), respectively. The spectra were interpreted in terms of fundamentals modes, combination and overtone bands. The structure of the molecule was optimized and the structural characteristics were determined by density functional theory (DFT) using B3LYP method with 6-311++G(d,p) as basis set. The vibrational frequencies were calculated for monomer and dimer by DFT method and were compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. The infrared and Raman spectra were also predicted from the calculated intensities. (13)C and (1)H NMR spectra were recorded and (13)C and (1)H nuclear magnetic resonance chemical shifts of the molecule were calculated using the gauge independent atomic orbital (GIAO) method. UV-visible spectrum of the compound was recorded in the region 200-400nm and the electronic properties HOMO and LUMO energies were measured by time-dependent TD-DFT approach. The geometric parameters, energies, harmonic vibrational frequencies, IR intensities, Raman intensities, chemical shifts and absorption wavelengths were compared with the available experimental data of the molecule.

Molecular structure, vibrational spectroscopic, first-order hyperpolarizability and HOMO, LUMO studies of 2-aminobenzimidazole

In the present work, we reported a combined experimental and theoretical study on molecular structure, vibrational spectra and HOMO-LUMO analysis of 2-aminobenzimidazole (2-ABD). The FTIR (400-4000 cm(-1)) and FT-Raman spectra (50-3500 cm(-1)) of 2-ABD were recorded. The molecular geometry, harmonic vibrational wavenumbers and bonding features of 2-ABD in the ground-state have been calculated by using the density functional B3LYP method with 6-311++G(d,p) and 6-31G(d) as basis sets. The energy and oscillator strength were calculated by time-dependent density functional theory (TD-DFT) result complements with the experimental findings. The calculated HOMO and LUMO energies showed that charge transfer occurs within the molecule. Finally, the calculation results were applied to simulate infrared and Raman spectra of the title compound which showed good agreement with the observed spectra.

The role of oxidative stress in diabetic cardiomyopathy: an experimental study

BACKGROUND

Diabetes mellitus (DM) has a negative effect on cardiovascular functions. Little, however, is known of the overall effect of DM on the cardiac histology or the pathophysiological basis of this.

AIM

We aimed to investigate the role of oxidative stress on the pathogenesis of diabetic cardiomyopathy in an experimental model.

MATERIALS AND METHODS

12 week-old female Sprague Dawley rats were randomly allocated into a healthy control group (n=6) and an DM group (n=6). After 12 weeks of alloxan induced DM, the groups' cardiac tissues were histopathologically analyzed and examined for determination of oxidant and antioxidant enzymes [activities of catalase (CAT), superoxide dismutase (SOD), and myeloperoxidase (MPO) and amount of reduced glutathione (GSH) and lipid peroxidation (LPO)].

RESULTS

When compared to the control group, the DM group showed cardiomyopathic changes. In the DM group, activities of CAT (144 +/- 0.9 vs. 112 +/- 1.4, p < 0.05) and LPO amount (27.0 +/- 0.74 vs. 14.4 +/- 0, 20, p < 0.05) were significantly increased whereas activities of SOD (142 +/- 0.2 vs. 146 +/- 0.7, p < 0.05) and amount of GSH (3.48 +/- 0.01 vs. 3.73 +/- 0.01, p < 0.05) were significantly decreased when compared to the control group. Besides, activities of MPO (7.3 +/- 0.02 vs. 8.6 +/- 0.11, p < 0.05) were comparable between groups.

CONCLUSIONS

Using the experimental animal model, we were able to demonstrate that DM causes cardiomyopathic changes, and we propose that these changes could be mediated by an oxidative stress.

Molecular structure, vibrational, UV and NBO analysis of 4-chloro-7-nitrobenzofurazan by DFT calculations

In the present work, we reported a combined experimental and theoretical study on molecular structure, vibrational spectra and NBO analysis of 4-chloro-7-nitrobenzofurazan (NBD-Chloride). The FT-IR (400-4000 cm(-1)) and FT-Raman spectra (50-4000 cm(-1)) of NBD-Chloride were recorded. The molecular geometry, harmonic vibrational frequencies and bonding features of NBD-Chloride in the ground-state have been calculated by using the density functional B3LYP method with 6-311++G (d, p) as higher basis set. The energy and oscillator strength calculated by time-dependent density functional theory (TD-DFT) result in DMSO and CDCl3 solvents complements with each other. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. Finally the calculation results were applied to simulate infrared and Raman spectra of the title compound which show good agreement with observed spectra.

Rare mechanical complication of myocardial infarction: isolated right ventricle free wall rupture

Rupture of the left ventricular free wall is a dramatic complication of acute myocardial infarction (MI) and occurs in about ten percent of patients with fatal acute MI. However, there are limited reports about right ventricular free wall rupture due to MI. In this case report, a patient with isolated right ventricular rupture following MI that was visualised with real-time transthoracic echocardiography is discussed for the first time in the literature.

Use of Ankaferd Blood Stopper for controlling actively bleeding fundal varices

Variceal bleeding is one of the most important and life-threatening complications of portal hypertension. Although less common than oesophageal varices that have a lower frequency of bleeding, gastric varices tend to result in more severe and mortal bleeding. The Ankaferd Blood Stopper (ABS) has been used with varying success in recent years for the management of bleeding from skin lesions or after dental surgery, and in other clinical conditions in which conventional haemostatic measures have proved to be deficient. In serious bleeding gastric fundal varices, ABS can also act as a bridge in the absence or unavailability of definitive therapies.

Molecular structure, anharmonic vibrational frequencies and NBO analysis of naphthalene acetic acid by density functional theory calculations

In this work, we report anharmonic vibrational frequencies, molecular structure, NBO and HOMO, LUMO analysis of naphthalene acetic acid (NAA). The optimized geometric bond lengths and bond angles obtained by computation show good agreement with experimental X-ray data. The computed dimer parameters also show good agreement with experimental data. Anharmonic frequencies of NAA were determined and analyzed by DFT level of theory utilizing 6-311+G(d,p) basis set. Good agreement between the calculated and experimental spectra was obtained. Stability of the molecule arising from hyperconjugative interactions and charge delocalization have been analyzed using natural bond orbital (NBO) analysis. The results show that charge in electron density (ED) in the pi* and sigma* antibonding orbitals and E2 energies. This confirms the occurrence of ICT (Intermolecular Charge Transfer) within the molecule. The calculated HOMO and LUMO energies also show that charge transfer occurs within the molecule.

Early reintubation after cardiac operations: impact of nasal continuous positive airway pressure (nCPAP) and noninvasive positive pressure ventilation (NPPV)

BACKGROUND

Due to an increasing number of comorbidities there is still a significant incidence of respiratory failure after primary postoperative extubation in patients who undergo cardiosurgery. We wanted to study whether nCPAP could improve pulmonary oxygen transfer and avoid the necessity for reintubation after cardiac surgery. Additionally, we compared this protocol to noninvasive positive pressure ventilation (NPPV).

PATIENTS AND METHODS

Over a period of 3 years we analyzed all patients who were extubated within 12 hours after cardiac surgery, and in whom pulmonary oxygen transfer (PaO₂/FIO₂) deteriorated without hypercapnia so that all these patients met predefined criteria for reintubation. There were three groups of patients: A = patients required immediate reintubation (n = 125); B = patients had nCPAP with intermittent mask CPAP (n = 264); and C = patients had NPPV (n = 36).

RESULTS

25.8 % of patients in Group B and 22.2 % of patients in Group C were also intubated after a period of CPAP or NPPV. All other patients of Groups B and C could be weaned from these devices (B: 33.4 ± 5.8 hours, C: 26.2 ± 4.2 h; P < 0.05) and were well oxygenated using a face mask at ambient pressures (PaO₂/FIO₂: B: 136 ± 12, C: 141 ± 12). In Group A, we found a higher mortality (8.8 %) than in Group B (4.2 %) and Group C (5.6 %). The ICU stay and in-hospital stay were significantly prolonged in Group A. The incidence of pulmonary infections (A: 24 %, B: 10.6 %, C: 13.8 %; P < 0.05) and the need for catecholamines were significantly increased in Group A, whereas nCPAP patients suffered significantly more often from impaired sternal wound healing (A: 4.8 %, B: 8.3 %; P < 0.05).

CONCLUSIONS

We conclude that reintubation after cardiac operations should be avoided since nCPAP and NPPV are safe and effectively improve arterial oxygenation in the majority of patients with nonhypercapnic oxygenation failure. However, it is of great importance to pay special care to sternal wound complications in these patients.

Predictors of postoperative complications in octogenarians undergoing cardiac surgery

OBJECTIVE

Aim of the study was to clarify the impact of different pre- and perioperative conditions on outcome in octogenarians undergoing cardiac surgery.

METHODS

We retrospectively analyzed preoperative risk factors and intraoperative adverse events and studied in-hospital morbidity and mortality in 646 patients > or = 80 years of age (82.5 +/- 3.5 years) and in 6081 younger patients (70.3 +/- 3.4 years) who underwent cardiac surgery between 1/2001 and 12/2006.

RESULTS

Preoperatively, octogenarians suffered significantly more from arterial hypertension, renal failure, previous neurological problems, unstable angina and NYHA class IV than younger subjects. The incidence of combined valve and coronary procedures and of urgent operations was also significantly higher in patients > or = 80 years (27.7 % vs. 18.2 %, P < 0.05, and 7.3 % vs. 4.2 %, P < 0.05, respectively). In-hospital mortality was higher (7.4 % vs. 3.7 %, P < 0.05), and average ICU and total in-hospital stay was longer in the older age group. Postoperative complications occurred in 15 % of patients > or = 80 years compared to 7.6 % of patients < or = 79 years ( P < 0.05). NYHA class IV, female sex and preoperative renal failure correlated with perioperative morbidity. Multivariate analysis could identify urgent procedures, redo surgery, mitral valve surgery and prolonged cross-clamping times as predictors of mortality.

CONCLUSIONS

Cardiac surgery in octogenarians can be performed with an acceptable risk but an increased mortality and morbidity compared to younger patients. High-risk octogenarians, who require intensive perioperative management, should be identified to reduce the incidence of postoperative complications.

The impact of pre- and postoperative renal dysfunction on outcome of patients undergoing coronary artery bypass grafting (CABG)

OBJECTIVE

Acute changes in renal function after elective coronary bypass surgery represent a challenging clinical problem. In this study, we evaluated perioperative risk factors for the development of postoperative renal dysfunction (PRD), and the impact of such an event on the perioperative course. Additionally, we investigated the influence of preoperatively mildly increased serum creatinine on perioperative mortality and morbidity.

METHODS

We retrospectively analyzed data of 2511 patients undergoing isolated CABG between 2004 and 2007 with a preoperative serum creatinine < or = 2.2 mg/dL. There were 592 patients with a preoperative serum creatinine of between 1.4 and 2.2 mg/dl (mild renal dysfunction group) and 1919 patients with a serum creatinine < 1.4 mg/dl. Perioperative risk factors for PRD were analyzed by multivariate regression analysis.

RESULTS

Global in-hospital mortality was 3.1 %.The incidence of PRD was 6.2 %. Mortality for patients who had PRD was 7.8 vs. 2.9 % for patients who did not ( P < 0.05). PRD increased the length of hospital stay by 3.7 days (12.2 vs. 15.9; P < 0.05). Multivariate logistic regression identified the following variables as independent predictors of PRD: age, angina class III/IV, diabetes mellitus, prolonged cardiopulmonary bypass time, and preoperative serum creatinine. With regard to preoperative renal function, we found that operative mortality was higher in the mild renal dysfunction group (5.7 % vs. 2.5 %; P < 0.05). New dialysis/hemofiltration (5.1 % vs. 1.2 %; P < 0.05) and postoperative stroke (5.1 % vs. 1.6 %; P < 0.05) were also more common in these patients.

CONCLUSIONS

Mild renal dysfunction preoperatively is an important predictor of outcome after CABG. In these patients, PRD dramatically increases mortality, morbidity and length of hospital stay.

FT-IR, FT-Raman, NMR spectra and DFT calculations on 4-chloro-N-methylaniline

In this work, the vibrational spectral analysis was carried out by using FT-IR and FT-Raman spectroscopy in the range 400-4000 and 50-3500cm(-1) respectively, for the title molecule. The structural and spectroscopic data of the molecule in the ground state were calculated by using density functional method using 6-311++G(d,p) basis set. The vibrational frequencies were calculated and scaled values were compared with experimental FT-IR and FT-Raman spectra. The observed and calculated frequencies are found to be in good agreement. The complete assignments of all the vibrational mode were performed on the basis of the total energy distributions (TED). (13)C and (1)H NMR chemical shifts results were given and are in agreement with the corresponding experimental values. The theoretically constructed FT-IR and FT-Raman spectra exactly coincides with experimental one.

Platelet-function analyzer closure times indicate shear stress-induced hemostatic abnormalities in patients with aortic valve stenosis and correlate with perioperative transfusion requirements

BACKGROUND

Shear stress-induced hemostatic abnormalities are highly prevalent in patients with aortic valve stenosis. In this study, we determined closure times with a platelet-function analyzer (PFA-100, Dade Behring, Marburg, Germany) in patients admitted for aortic valve replacement to assess the correlation with the severity of aortic valve stenosis, blood loss, perioperative transfusion requirements, and need for re-thoracotomy.

PATIENTS AND METHODS

Fifty consecutive patients (mean age [+/- SD] 68 +/- 9 years) were enrolled. Closure times of epinephrin/collagen and adenosine diphosphate (ADP)/collagen cartridges were determined at least ten days after discontinuation of antiplatelet medication and compared to those of healthy control subjects without medication.

RESULTS

Closure times of epinephrin/collagen (210 +/- 69 sec vs. 140 +/- 50 sec, p < 0.0001) and ADP/collagen (145 +/- 58 sec vs. 108 +/- 45 sec, p < 0.0001) cartridges were prolonged in patients with aortic valve stenosis. Intraoperative transfusion of red blood cell units was associated with the closure times of epinephrin/collagen (r = 0.28, p = 0.04) and ADP/ collagen cartridges (r = 0.28, p = 0.04). Total transfusion of red blood cell units was associated with ADP/ collagen closure times (r = 0.31, p = 0.02), but not epinephrin/collagen closure times (r = 0.26, p = 0.07). No significant association of closure times with intraoperative, postoperative and total transfusion of fresh frozen plasma units was observed.

CONCLUSIONS

Prolongation of closure times determined with a platelet-function analyzer is highly prevalent in patients with aortic valve stenosis and appears to reflect shear stress-induced hemostatic abnormalities. Since prolonged closure times are associated with increased perioperative transfusion of red blood cell units, the assay could significantly contribute to the identification of individuals at risk.