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Rotational angular momentum alignment effects in the rotational inelastic scattering of NO(X) with Ar have been investigated by means of close-coupled quantum mechanical, quasi-classical trajectory, and Monte Carlo hard shell scattering calculations. It has been shown that the hard shell nature of the interaction potential at a collision energy of Ecoll = 66 meV is primarily responsible for the rotational alignment of the NO(X) molecule after collision. By contrast, the alternating trend in the quantum mechanical parity resolved alignment parameters with change in rotational state Δj reflects differences in the differential cross sections for NO(X) parity conserving and changing collisions, rather than an underlying difference in the collision induced rotational alignment. This suggests that the rotational alignment and the differential cross sections are sensitive to rather different aspects of the scattering dynamics. The applicability of the kinematic apse model has also been tested and found to be in excellent agreement with exact quantum mechanical scattering theory provided the collision energy is in reasonable excess of the well depth of the NO(X)-Ar potential energy surface. [ABSTRACT FROM AUTHOR]

Classical and quantum mechanical expressions for the j-j′ vector correlation (also referred to as the rotational tilt) are presented for the situation in which the initial and final relative velocity directions are unresolved. The quantum mechanical expressions are compared with previous descriptions in the literature. It is shown that in the case of 2S+1Σ radicals in collision with closed shell species, a tensor opacity formalism can be employed in quasiclassical trajectory calculations to provide classical estimates of both open shell spin-rotation state and nuclear hyperfine state changing (or conserving) cross sections. Polarization parameters are also obtained from the same formalism. The method is applied to calculations on the OH(A 2Σ+)–Ar system using a recently developed potential energy surface. The results of both the closed and open shell quasiclassical trajectory calculations are found to compare favorably with those from close-coupled closed and open shell quantum mechanical scattering calculations. The accompanying paper provides an experimental test of these calculations and of the potential energy surface they employ. [ABSTRACT FROM AUTHOR]

This article uses theoretical methods to study the dependence on stereodynamical factors of the mechanism and reactivity of the F+H2 reaction at low and ultralow collision energies. The impact of polarization of the H2 reactant on total and state-to-state integral and differential cross sections is analyzed. This leads to detailed pictures of the reaction mechanism in the cold and ultracold regimes, accounting, in particular, for distinctions associated with the various product states and scattering angles. The extent to which selection of reactant polarization allows for external control of the reactivity and reaction mechanism is assessed. This reveals that even the simplest of reactant polarization schemes allows for fine, product state-selective control of differential and (for reactions involving more than a single, zero orbital angular momentum partial wave) integral cross sections. [ABSTRACT FROM AUTHOR]

Near-edge x-ray-absorption fine-structure (NEXAFS) spectra of 1-butene (C4H8), acrylonitrile (C2H3CN) and 1,3-butadiene (C4H6) multilayers were recorded with high resolution (better than 100 meV at the carbon edge) and a theoretical method to interpret the vibrational structure of the observed C1s→π* bands is presented. The method is based on local (quadratic) approximations for the potential energy surfaces of both ground and excited electronic states, with input data obtained by ab initio calculations of normal modes for the ground state and energy gradients for the excited state within the framework of the equivalent core model. The method proved to be useful in qualitative terms, providing information on the nature of the excited modes and on the geometrical changes following the electronic excitation. We have also calculated the C1s→π* spectrum of ethylene (C2H4) and compared it to those obtained for C4H8, C2H3CN, and C4H6. Since the latter can be considered as substituted ethylenes, the validity of the building-block scheme for the vibrational splittings in inner-shell absorption spectra could be assessed by this comparison. [ABSTRACT FROM AUTHOR]

Xylem colonization by Xylella fastidiosa promotes physiological, biochemical, and morphological alterations in citrus plants causing citrus variegated chlorosis (CVC) disease, which might influence the feeding behavior of vectors of this bacterial pathogen and its spread in citrus groves. By using the electrical penetration graph technique, we compared the numbers and durations of stylet penetration activities by adults of the sharpshooter vector Bucephalogonia xanthophis (Berg) (Hemiptera: Cicadellidae) on healthy and X. fastidiosa-infected sweet orange seedlings (Citrus sinensis (L.) Osbeck, cv. Pera). Infected plants were either symptomatic, exhibiting the typical CVC, symptoms or totally asymptomatic. The mean time needed to contact xylem and start xylem sap ingestion after the onset of the first probe was similar among treatments. However, the average time elapsed between the onset of the first probe and the beginning of sustained xylem ingestion (>5 min) was longer on plants with CVC symptoms than on infected asymptomatic or healthy plants. In addition, the length of time spent in ingestion activities was much shorter on symptomatic plants. Our results showed that CVC symptomatic citrus plants were a less acceptable host than uninfected or asymptomatic X. fastidiosa-infeeted plants. Furthermore, our results support the hypothesis that symptomless infected citrus trees may be more important as sources for CVC spread than severely diseased ones. [ABSTRACT FROM AUTHOR]

From a kinetics standpoint, reactive molecular collisions are the building blocks of the mechanisms of chemical reactions. In contrast, a dynamics standpoint reveals molecular collisions to have their own internal mechanisms, which are not mere theoretical abstractions: through suitable preparation of the reactants internal and stereochemical states, features of the mechanisms of a reactive molecular collision can be made evident and used as “handles” to control the reaction outcome. Using time-independent quantum dynamical calculations, we demonstrate this for the Br + H2(v = 0–1, j = 2) → H + HBr reaction in the 1.0–1.6 eV range of total energies. Despite its pronounced effect on reactivity, which is in agreement with the predictions from Polanyi rules, reactant vibration is found to have little effect on the mechanism of this endoergic, late-barrier reaction. Analysis of the correlations between directional reaction properties shows that the collision stereochemistry strongly depends on the total energy, but not on how this energy is partitioned between reactant translation and vibration. The stereodynamical preferences implied by the collision mechanisms determine how and to what extent one can control the reaction. Regarding the overall reaction, the extent of control is found to be large near the reaction threshold but not when the total energy is high. Regarding state-to-state reactions, the effect of reactant stereochemistry on the product rotational state distribution is found to be nontrivial and energy dependent. [ABSTRACT FROM AUTHOR]

Colorado State University has created a joint education-engineering degree program between the School of Education and the College of Engineering. The objectives for developing this new program include: to improve secondary education through highly qualified technology teachers; to place engineering graduates in the secondary classroom where they can encourage a more diverse group of potential engineering students at an early age; to attract a more diverse student population into engineering undergraduate programs; and to better prepare students in science, technology, engineering, and mathematics (STEM) for entering into an engineering undergraduate program. The study of engineering in education helps create a citizenry that is highly literate, disciplined, is capable of thinking critically and creatively, is knowledgeable about a range of cultures, and is able to participate actively in discussions about new discoveries and choices. Colorado State University is taking a leadership role in initiating systemic change that will positively influence the future of all K-12 education. This new joint degree program is built on new partnerships across traditional academic and disciplinary lines to innovate, cooperate and prepare highly qualified teachers. [ABSTRACT FROM AUTHOR]

The endoscopic Congo red test (ECRT) was performed in 43 patients who underwent proximal gastric vagotomy (PGV) for duodenal ulcer (DU). The aim of the study was to develop a standard and reliable way to interpret the results obtained in this test. Thus, the results of ECRT were related to post-operative clinical evaluation and to pre- and post-operative basal and pentagastrin-stimulated gastric acidity. Whenever ECRT was considered positive, we called it in "large extension" if a red-to-black colour change occurred in three or more of the areas studied. Positive ECRT was observed in 39 patients (90.7%). There was a statistically significant (P less than 0.01) correlation between poor clinical results and positive ECRT in "large extension". We concluded that: (1) a positive ECRT result has no clinical or prognostic significance in DU patients after PGV; (2) ECRT, analysed according to the extension of the areas turning black, is a practical and reliable method to establish clinical results and prognosis in these patients. [ABSTRACT FROM AUTHOR]

Hepatitis B (HBV) is a public health problem worldwide; one-third of the population has already been in contact with HBV, and 350 million people are chronic carriers of virus. The appearance of hyperimmune gamma globulin and antiviral drugs has allowed that group to undergone hepatic transplantation, achieving satisfactory results to prevent a relapse. But the use of hyperimmune gamma globulin has an extremely high cost, and combined therapies with new antiviral drugs seem to be a therapeutic alternative. We analyzed 21 patients with hepatitis B associated or not with Delta hepatitis over a mean follow-up period of 19.5 months, concluding that use of only nucleotide analogues has sufficient to achieve satisfactory results., (Copyright (c) 2010 Elsevier Inc. All rights reserved.)

Background: After the development of highly active antiretroviral therapy (HAART) for patients with human immunodeficiency virus (HIV), there has been increased interest in organ transplantation for this selected population. There is a lack of reports about pancreas transplant in HIV+ recipients., Case Report: We report the case of a 43-year-old HIV+ man who presented with type 1 diabetes for 25 years and end-stage-renal disease. He underwent dialysis therapy for the prior 3 years. His CD4 count was 830 cells/mL and a negative viral load was achieved after 3 months of antiretroviral therapy. His nutritional status was favorable; no opportunistic infections had occurred. A simultaneous pancreas-kidney transplantation (SPKT) was performed from a 19-year-old deceased trauma victim. Pancreas implantation was enteric-portal drainage. No induction immunosuppression was used, but rather tacrolimus, sodium mycophenolate, and steroids. In the postoperative period, there was a delayed kidney graft function requiring hemodialysis for 14 days. On postoperative day 11, a kidney biopsy specimen showed mild rejection, which was successfully treated with steroids. The patient was discharged after 22 days; he was normoglycemic and insulin-independent with a serum creatinine value of 1.9 mg/dL. Currently, his outcome has been uneventful, without a readmission or opportunistic infections. After 5 months postoperation, the viral load is negative and the CD4 count is 460 cells/mL. The current serum creatinine level is 1.1 mg/dL; no insulin has been required., Comment: HIV has been considered to be an absolute contraindication to organ transplantation, because of the infection risk due to severe immunosuppression, to interactions between antiretroviral and immunosuppressive drugs, and to reluctance to offer an organ to a terminal patient. However, transplants in HIV+ patients have shown good results, when a patient has an acceptable CD4 level, a low viral load, and minimal antiretroviral therapy., (Copyright (c) 2010 Elsevier Inc. All rights reserved.)

Classical and quantum mechanical expressions for the j-j(') vector correlation (also referred to as the rotational tilt) are presented for the situation in which the initial and final relative velocity directions are unresolved. The quantum mechanical expressions are compared with previous descriptions in the literature. It is shown that in the case of (2S+1)Sigma radicals in collision with closed shell species, a tensor opacity formalism can be employed in quasiclassical trajectory calculations to provide classical estimates of both open shell spin-rotation state and nuclear hyperfine state changing (or conserving) cross sections. Polarization parameters are also obtained from the same formalism. The method is applied to calculations on the OH(A (2)Sigma(+))-Ar system using a recently developed potential energy surface. The results of both the closed and open shell quasiclassical trajectory calculations are found to compare favorably with those from close-coupled closed and open shell quantum mechanical scattering calculations. The accompanying paper provides an experimental test of these calculations and of the potential energy surface they employ.

The effect of reactant polarisation on the dynamics of the title reaction at collision energies up to 1.6 eV is analysed in depth. The analysis takes advantage of two novel theoretical concepts: intrinsic reaction properties and stereodynamical portraits. Exact quantum methods are used to determine the polarisation moments that quantify the intrinsic reactant polarisation at various levels of detail, including or not product state and/or scattering angle resolution. The data is then examined with the aid of stereodynamical portraits, which facilitate the rationalisation of the stereochemical effects that are relevant for the reaction dynamics. This allows for detailed characterisations of the so-called direct and delayed reaction mechanisms.

Combined liver-pancreas procurement generally requires back bench reconstruction of the arterial blood supply with a donor Y-iliac graft to the pancreas graft. A modified vascular reconstruction that uses donor aortic cross including the brachiocephalic trunk and the left carotid artery as a single arterial patch is presented. This is useful when iliac grafts are unavailable or are being used as an alternative technique.

During the past 20 years, several authors have reported increased prevalence of cholelithiasis in liver cirrhosis. This biliary disease has been implicated with the deterioration of liver function, liver disease of alcoholic origin or even the presence of hypersplenism in this patient population. This study analyzes the incidence and possible factors which are responsible for promoting cholelithiasis in cirrhosis. The study included 110 cirrhotic patients of a private center specialized in treating liver diseases. The incidence of cholelithiasis was 27.3% (25.3% in males and 33.3% in females). There was no correlation between liver function defined by Child's classification or through the laboratory examinations (AST, ALT, AP, GGT, PT, Alb, TB, DB, PA) and the presence of gallstones. No evidence was found that the etiology of cirrhosis or the presence/absence of hypersplenism affected the prevalence of cholelithiasis in this population. In conclusion, an increased prevalence of cholelithiasis was verified in this population of cirrhotics but the pathogenesis is still obscure.

Hemangiomas are the most common benign vascular tumor found in the liver. In this study, 103 cases of hepatic hemangiomas were analysed in a retrospective manner. Image aspects such as those seen in ultrassonography, computed tomography, nuclear magnetic resonance and arteriography are discussed. The incidence was higher amongst the female sex, between individuals from 40 to 60 years old, which presented predominantly without symptoms (66%) and localized mainly in the right hepatic lobe (74%). The meaning of those aspects, when adopted, permits the clinicians to differentiate benign from malignant nodular lesions in the liver.

Cholecystectomy in cirrhotic patients is commonly followed by high morbidity and mortality. In our study, laparoscopic cholecystectomy was performed in 12 cirrhotic patients (eight Child A and four Child B) in an effort to obtain lower complication and mortality rates. The mean age of the group was 51.8 years; seven of the 12 patients were men. Four patients had liver disease from virus B, five from virus C, one because of alcohol, and two had cryptogenic liver cirrhosis. The average operative time was 157 min. Intraoperative cholangiography could be performed in eight cases. No mortality or need to perform laparotomy occurred. Only one patient required blood transfusion (8.3%). Postoperative complications occurred in four patients, but these were easily controlled and included renal failure, diabetic impairment, hematoma with ascitic leakage through the wound, and wound abscess, one case each. No postoperative liver failure was observed. All patients walked and were refed in the first 24 h after surgery. They were dismissed in an average period of 2.5 days. Our primary view demonstrated that laparoscopic cholecystectomy was safe and well tolerated by selected cirrhotic patients (Child A and B) with clear indication for surgery.

Thirty-six patients with pyogenic liver abscess treated by percutaneous drainage plus antibiotic therapy were reviewed. The most frequent symptoms were fever (75%) and pain (72.2%), and the most common physical signs were liver enlargement (58.3%) and jaundice (33.3%). The mean time interval from admission to diagnosis was 16 days. CT scans and ultrasonography were diagnostic in 100% of the patients. The percutaneous drainage was effective in one attempt in 19 patients, two attempts in 8, three attempts in 8 patients and more than four attempts in only one patient. There were three patients with hemoperitoneum (8.7%) as a post-drainage complication, one of them needed to be treated surgically. Mean hospital stay was of 24.8 days and the mortality rate was 5.5%. Percutaneous drainage plus antibiotic therapy is then an efficient therapeutic approach to the treatment of pyogenic liver abscess.

Anastomotic dehiscence remains the main cause of morbidity and mortality of intestinal resections, mainly the colorectal (77, 95, 110). Very often in the literature the words dehiscence and fistula are misused for the same meaning. Nevertheless, attention must be paid to the fact that these two situations may be distinct. Dehiscence is defined as the failure of healing of the anastomoses, while fistula is the leakage of the intestinal content into the peritoneal cavity. So, the evidence of fistula is always accompanied by dehiscence, although a dehiscence may not develop into a fistula, should it be blocked by omentum or surrounding organs (110, 117). The incidence of overt dehiscence varies from 0.1% to 30% in the literature (13, 15, 17, 27, 31, 40, 44, 46, 76, 77, 81, 96, 113, 120, 123, 126, 133, 135). The Colon Cancer Project of the Saint Mary's Hospital in London, a multicentric study of patients submitted to bowel resections revealed a post operative mortality of 22% in patients with dehiscence and 7% for uncomplicated anastomoses. This led to the struggle various authors to achieve better results, regarding techniques and suture materials, such as the number of planes involved, inverted or everted sutures, wound healing and the influence of local and systemic factors, like infections, antibiotics, NSAIDs on sutures. Recently, surgical stapling gained importance among surgeons, due to its technical advantages. However, this is still very controversial and must undergo further investigations (93, 107, 109, 112, 115, 116). So, in order to understand the pathophysiology of the complications and to reduce morbidity and mortality, related to intestinal anastomoses, it is necessary to study the events involved in intestinal healing after resection, as well as the technique, materials used and the factors related to anastomotic failure.

As a contribution to the study of ascites in patients with liver cirrhosis, congestive heart failure and peritoneal carcinomatosis evaluate in serum and ascites the concentrations of alphafetoprotein, carcinoembryonic antigen and fibronectin, they might suggest a diagnosis for the basic pathology. Forty-seven patients were studied, from whom 23 with cirrhosis, 17 peritoneal carcinomatosis and 7 with congestive heart failure. We conclude that: a) none of the tools usually employed in the analysis of ascitic fluid alone can make the base pathological process responsible for producing ascites; b) fibronectins were more useful for differential diagnosis between cirrhosis and carcinomatosis; c) alpha-fetoprotein and carcinoembryonic antigen were not useful for the definition for differential diagnosis.

In the authors' experience, 0.24% of the patients submitted to liver imaging (ultrasound or computerized tomography) have hemangiomas. These are shown as solid nodular lesions, mostly found by chance. Sometimes they do not appear as typical solid vascular lesions. The authors' experience and the literature are discussed. A clear and concise approach to this benign neoplasm is suggested.

In the period of January 1978 to October 1988, 32 Le Veen shunts (LVS) were implanted in 20 patients, out of which 16 were alcoholic cirrhotics and 4 postnecrotic cirrhotics. In the present study, we correlated preoperative laboratory data of these patients with their postoperative evolution, comparing the clinical results of patients who survived more than 30 days (13 patients = 65%) with the results of those who died within the same period (7 patients = 35%). For that matter, 14 laboratory tests were performed in order to measure the serum levels of hematocrit, hemoglobin, urea, creatinine, sodium, potassium, bilirubin, albumin, AST, ALT, alkaline phosphatase, fibrinogen, gamma GT and prothrombin activity. After statistical analysis, we observed that 6 of the 14 tests performed could be considered of prognostic value in the following decreasing order of importance: fibrinogen, alkaline phosphatase, prothrombin activity, urea, gamma GT and bilirubin. We observed that all the 7 patients who died prematurely presented 3 or more of these levels altered, when compared with standard values. Based on these data, we concluded that serum levels of fibrinogen, alkaline phosphatase, urea, gamma GT, bilirubin and activity of prothrombin proved to be important factors in determining the prognosis of immediate survival in cirrhotic patients who underwent LVS implantation. We also concluded that when 3 or more of these factors are altered, the implant of LVS is contraindicated, whatever clinical criteria for indication and contraindication were taken into account.