Alternative CNDOL Fockians for fast and accurate description of molecular exciton properties.

CNDOL is an a priori, approximate Fockian for molecular wave functions. In this study, we employ several modes of singly excited configuration interaction (CIS) to model molecular excitation properties by using four combinations of the one electron operator terms. Those options are compared to the experimental and theoretical data for a carefully selected set of molecules. The resulting excitons are represented by CIS wave functions that encompass all valence electrons in the system for each excited state energy. The Coulomb-exchange term associated to the calculated excitation energies is rationalized to evaluate theoretical exciton binding energies. This property is shown to be useful for discriminating the charge donation ability of molecular and supermolecular systems. Multielectronic 3D maps of exciton formal charges are showcased, demonstrating the applicability of these approximate wave functions for modeling properties of large molecules and clusters at nanoscales. This modeling proves useful in designing molecular photovoltaic devices. Our methodology holds potential applications in systematic evaluations of such systems and the development of fundamental artificial intelligence databases for predicting related properties.

p53 protein accumulation predicts malignant progression in Barrett's metaplasia: a prospective study of 275 patients.

AIMS: The purpose of this study was to determine prospectively whether p53 protein accumulation in biopsies of Barrett's metaplasia (BM) is a predictor of malignant progression, without relying on dysplasia grading. METHODS AND RESULTS: Sections of formalin-fixed paraffin-embedded tissue from the initial biopsies of 275 patients with BM, who had no high-grade dysplasia (HGD) or oesophageal adenocarcinoma (EAC), were stained for p53 by immunohistochemistry. The mean follow-up was 41 months. p53-positive biopsies were divided into four groups: scattered positive cells, multifocal scattered positive cells, aggregates of positive cells, and multifocal aggregates of positive cells. Kaplan-Meier analysis with the log-rank test was used to determine the rate of progression to HGD/EAC. Of the 275 patients, 227 had initial biopsies that were completely negative for p53, and, of these, one (0.4%) progressed to HGD/EAC; none of 24 (0%) patients with scattered positive cells and none of four (0%) of patients with multifocal scattered positive cells progressed. In contrast, five of 16 (31.25%) patients with aggregates of positive cells and three of four (75%) of those with multifocal aggregates of positive cells progressed to HGD/EAC. Kaplan-Meier analysis with log-rank statistics showed the difference in progression rate between the five groups to be highly significant (P < 0.0001). CONCLUSIONS: We conclude that p53 protein accumulation, detected by immunohistochemistry in aggregates of cells, is a significant predictor of malignant progression in patients with BM.

Thermomechanical characterisation data of 30 g/m2 and 150 g/m2 cured unidirectional carbon/epoxy tape prepreg TP 402/T700S.

With the aim to calculate through the Classical Laminate Theory the most reliable stress value generated in the 90° layer of cross-ply laminates tested under fatigue loading [1], the mechanical and thermal properties were measured for a novel composite material TP402/T700S 12K/35% using two different unidirectional tape prepregs, 30 and 150 g/m2. 0° unidirectional (UD-0), 90° unidirectional (UD-90), ±45°, 10° off-axis and samples for thermal properties measurements were manufactured in an autoclave. Tensile and thermal tests were performed in an Instron 4482 and in an oven, respectively, using strain gauges for all of them. Data collected was analysed following technical standards. The values of the mechanical properties, i.e., elastic and shear stiffness and strength, and the coefficients of thermal expansion (CTEs), α 1 and α 2 , were calculated also obtaining the corresponding statistics.

A study of the reproducibility and reliability of the musculo-articular stiffness of the ankle joint.

The objective of this work was to evaluate the reproducibility, reliability and usefulness of the musculo-articular stiffness (MAS) of the ankle joint, measuring it by the free vibration technique. Seventeen (nine males and eight females) healthy university students were included in the study. Force (f), MAS (k) and unitary MAS (ku) (defined as the ratio between the value of stiffness k obtained in the test (absolute terms) and the value of force (f)) were obtained. A test-retest protocol was designed and performed on the same day to determine the short-term reproducibility of f, k and ku. Short-term reproducibility of k and ku on 1 day in absolute terms (< 7% Coefficient of Variation (CV)) and relative reproducibility (Intraclass Correlation Coefficient (ICC) and Pearson ≥ 0.97) for both feet were obtained. The reliability of k and ku in absolute terms (< 9% CV) and in relative terms (ICC and Pearson ≥0.93) based on repeating the protocol for 1 week was analysed for both feet. To analyse the usefulness, the Effect Size (ES) ratio = "Trivial" for all variables (for 1 day and 1 week) and the Smallest Worthwhile Change (SWC) ratio (Typical Error (TE)< SWC) = "GOOD" for k and ku (1 day and 1 week) were considered. The Minimal Difference needed to be considered "real" (MD) for ku ≅ 3.5% (1 day); ku≅ 8.5% (1 week) (p < 0.05) was obtained. The statistical analysis carried out displayed the high reproducibility, reliability and usefulness of the MAS test, which was more consistent with ku than k. Therefore, the unitary stiffness (ku) proven to be representative of the mechanical response of the ankle joint obtained by free vibration techniques, which allows comparison between different subjects.

Diverticula and Diverticulitis: Time for a Reappraisal.

Colonic diverticula are very common and may be associated with symptoms or complicated by diverticulitis and its associated problems. Many of the traditional concepts relating to the pathophysiology, prevention, and management of these entities have been questioned recently based on findings from high-quality prospective studies. Although dietary fiber may protect against symptoms and complications, its impact on the formation of diverticula may be limited. It is now evident that the risk for an episode of diverticulitis in an individual with diverticula is lower than previously thought. Furthermore, the necessity for antibiotic use in uncomplicated diverticulitis has been questioned and serious doubt cast upon the belief that surgery should be performed when a second attack occurs. Although data are far from conclusive, there is some evidence to suggest that diverticulosis may be associated with chronic abdominal symptoms, with or without underlying chronic inflammatory changes in the involved segment of the colon. In addition, colonoscopy is not routinely required after an attack of acute uncomplicated diverticulitis, as the risk of cancer in this population is not much higher than in the general population.

Evaluation of the stiffnesses of the Achilles tendon and soleus from the apparent stiffness of the triceps surae.

The triceps surae plays an important role in the performance of many sports. Although the apparent average mechanical properties of the triceps surae may be a satisfactory parameter for estimating the training level of an athlete, a knowledge of the mechanical properties of the individual constituents of the triceps surae (in particular the Achilles tendon and soleus) permits a more detailed and in-depth control of the effects of training from more physically based parameters. The objective of this work is therefore the estimation of the individual viscoelastic properties (stiffness and viscosity) of soleus and Achilles tendon from the apparent properties of the triceps surae obtained by free vibration techniques. Different procedures have been developed and discussed, showing a high degree of robustness in the predictions. The results obtained for a non-oriented set of subjects present a high level of variability, depending on the training conditions and anthropometric features, although the corresponding average values compare well with data previously reported in the literature, particularly those associated with the tendon stiffness.

Gastric carcinoids in patients with hypergastrinemia.

BACKGROUND: Hypergastrinemia in patients with pernicious anemia is a major regulator contributing to enterochromaffin-cell hyperplasia and, ultimately, to gastric carcinoids. STUDY DESIGN: Between 1990 and 2003, we studied 8 women and 10 men with pernicious anemia and gastric carcinoids; their mean age was 50 years. Serum gastrin levels ranged from 740 to 4,000 pg/mL (mean 1,000 pg/mL). Six patients underwent antrectomy, four total gastrectomy, and eight endoscopic resection or biopsy. During the same period, 22 patients with Zollinger-Ellison tumors and hypergastrinemia (20 men and 2 women, mean age 49 years) had no gastric carcinoids, but 1 of 7 patients with Zollinger-Ellison and multiple endocrine neoplasia (MEN1) tumors had hypergastrinemia and gastric carcinoids. RESULTS: Mean followup for pernicious anemia patients was 6 years after antrectomy and 1 to 10 years after endoscopic resection or biopsy. Tumor regression was observed in one patient after antrectomy and one patient after biopsy. There were no deaths in this group in spite of lymph node metastasis in two patients. The patient with Zollinger-Ellison and MEN1 syndrome has been followed 3 years after diagnosis and 2 years after total gastrectomy. CONCLUSIONS: Gastric carcinoids are indolent tumors occurring with increasing frequency in patients with pernicious anemia. Antrectomy or biopsy and observation are preferred methods of treatment. Total gastrectomy is reserved for patients with extensive tumor involvement of the gastric wall or for emergency bleeding.

Rectal duplication cyst in an adult: the laparoscopic approach.

BACKGROUND: Rectal duplication cyst (RDC) is a rare congenital anomaly representing 1% to 8% of all intestinal duplications. The case presented here is the first report of the laparoscopic resection of an RDC. METHODS: We report the case of a 49-year-old white woman in whom a retrorectal cystic mass measuring 5 x 5.3 x 6 cm was diagnosed. The mass was completely resected by means of laparoscopic techniques. RESULTS: Pathologic findings revealed a cystic structure partially lined with squamous as well as respiratory- and gastrointestinal-type epithelium. Muscularis propria was identified in the outer portions of the wall of the specimen. No atypia or malignancy was identified. The overall findings were consistent with an RDC. CONCLUSIONS: Laparoscopic resection constitutes an excellent and patient-friendly approach to the management of large adult cystic duplication of the rectum.

A critical study on the experimental determination of stiffness and viscosity of the human triceps surae by free vibration methods.

Muscles and tendons play an important role in human performance. Their mechanical behaviour can be described by analytical/numerical models including springs and dampers. Free vibration techniques are a widely used approach to the in vivo determination of stiffness and viscosity of muscle-tendon complexes involved in sport movements. By considering the data reported in the literature, it appears that the visco-elastic properties of the triceps surae muscle-tendon complexes are independent of the modality in which free vibration is induced as well as they do not depend on the composition of the population of subjects submitted to the experiments. This research will critically discuss this important aspect focussing in particular on two studies documented in the literature. For this purpose, two equipments will be developed to reproduce literature experiments under the assumption that the oscillating part of the body behaves as a single-degree-of-freedom system: The governing degree of freedom is associated with the vertical displacement of the lower leg or with the rotation of the foot around the ankle articulation. Unlike literature, measurements are now conducted on the same population of subjects in order to draw more general conclusions on the real equivalence of results and validity of the mechanical properties determined experimentally. Free vibration tests are accurately simulated by analytical models describing the response of each vibrating system. It is found that if the two measurement protocols are applied to the same population of individuals as it is done in this study, values of visco-elastic properties of muscle-tendon complexes extracted from experimental data are significantly different, the differences presenting a convincing consistency. This result is in contrast with the literature and confirms the need to evaluate results of free vibration techniques by taking homogeneous bases of comparison.

The significance of "indefinite for dysplasia" grading in Barrett metaplasia.

CONTEXT: For a confident diagnosis of dysplasia in Barrett metaplasia, the epithelial atypia should also involve the surface epithelium. However, pathologists are often faced with biopsies where the crypts show dysplasia, but the surface epithelium is either uninvolved or unevaluable. We previously grouped these cases with indefinite for dysplasia (IND). OBJECTIVE: To determine the clinical significance of IND grading in Barrett metaplasia. DESIGN: All biopsies from 276 prospectively followed patients with Barrett metaplasia, who did not have high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC) on initial biopsy, were graded as negative for dysplasia, IND, low-grade dysplasia (LGD), HGD, and EAC. Biopsies with multifocal IND or LGD were graded as INDM or LGDM, respectively. RESULTS: Only 3 of 193 patients (2%) with an initial diagnosis of negative for dysplasia and only 1 of 48 patients (2%) diagnosed with IND progressed to HGD or EAC. By contrast, 1 of 7 patients (14%) with INDM, 2 of 21 (10%) with LGD, and 1 of 7 (14%) with LGDM progressed to HGD or EAC. There was no significant difference in progression rate between patients with an initial diagnosis of negative for dysplasia and those diagnosed IND nor were there significant differences among patients with initial diagnoses of INDM, LGD, or LGDM. Kaplan-Meier analysis showed that patients with INDM, LGD, or LGDM on initial biopsy (group 1) were more likely to progress to HGD or EAC than were those patients who were diagnosed negative for dysplasia or IND (group 2; log-rank test, P < .001). CONCLUSIONS: Multifocal IND in an esophageal biopsy from a patient with Barrett metaplasia has the same clinical implication as LGD.

Utility of removable esophageal covered self-expanding metal stents for leak and fistula management.

BACKGROUND: Esophageal or gastric leakage from anastomotic wound dehiscence, perforation, staple line dehiscence, or trauma can be a devastating event. Traditional therapy has often consisted of either surgical repair for rapidly diagnosed leaks or diversion for more complicated cases, commonly associated with a delayed diagnosis. This study summarizes our experience treating leaks or fistulas with novel, covered self-expanding metal stents (cSEMS). The primary objective of this study was to determine the efficacy and safety of covered self-expanding metal stents when used to treat complicated leaks and fistulas. METHODS: Over 15 months, 25 patients with esophageal or gastric leaks were evaluated for stenting as primary treatment. A prospective database was used to collect data. Stents were placed endoscopically, with contrast evaluation used for leak evaluation. Patients who did not improve clinically after stenting or whose leak could not be sealed underwent operative management. RESULTS: During a mean follow-up of 15 months, 23 of the 25 patients with esophageal or gastric leaks during a 15-month period were managed with endoscopic stenting as primary treatment. Healing occurred in patients who were stented for anastomotic leakage after gastric bypass or sleeve gastrectomy (n = 10). One patient with three esophageal iatrogenic perforations healed with stenting. Eight patients successfully avoided esophageal diversion and healed with stenting and adjunctive therapy. Two of the 4 patients with tracheoesophageal fistulas sealed with the assistance of a new pexy technique to prevent stent migration; 1 additional patient had this same technique used to successfully heal an upper esophageal perforation. CONCLUSIONS: Esophageal leaks and fistulas can be effectively managed with cSEMS as a primary modality. The potential benefits of esophageal stenting are healing without diversion or reconstruction and early return to an oral diet.

Beta-blocker treatment of stable heart failure in primary care.

INTRODUCTION AND OBJECTIVES: Beta-blocker treatment of stable heart failure in primary care. The objective was to evaluate the feasibility and tolerability of uptitrating beta-blockers in patients with stable systolic heart failure seen in primary care. METHODS: Before and after intervention study. The study was conducted in two primary care centers in Barcelona, Spain. Consecutive samples of patients with systolic heart failure who had not received previous beta-blocker treatment were recruited between April 2004 and April 2006. Treatment was started with the lowest dose of bisoprolol or carvedilol and the dose was doubled every two weeks in the absence of contraindications. Patients were followed up for 6 months. RESULTS: The study included 88 patients (76.1% male, 23,9% female, mean age 64.88 years). Of these, 57.1% were treated with bisoprolol and 42.9% with carvedilol. Overall, 75.0% reached the target dose, 21.7% tolerated a dose lower than the target dose, and 3.3% had the beta-blocker withdrawn (due to bradycardia in 1.1%, syncope in 1.1%, and stroke in 1.1%). Adverse events were experienced by 70.4%, the majority of which (57.95%) were resolved without changing treatment. The most common were nausea (42.04%), asthenia (35.22%), and increased dyspnea (17.04%). There were significant improvements in functional class and ejection fraction. CONCLUSIONS: The majority of adverse events were mild. Treatment was withdrawn in only a few patients and most reached the recommended target dose. Appropriately trained primary care physicians can uptitrate beta-blockers in heart failure patients without undue concern.

Goblet cell mimickers in esophageal biopsies are not associated with an increased risk for dysplasia.

CONTEXT: Identification of intestinal-type goblet cells (ITGCs) in hematoxylin-eosin-stained sections of esophageal biopsies is essential for the diagnosis of Barrett metaplasia. However, we have seen cases diagnosed as Barrett metaplasia based solely on cells that pose morphologic similarity to ITGCs on hematoxylin-eosin staining or stain positive with Alcian blue. OBJECTIVE: To determine the clinical significance of goblet cell mimickers. DESIGN: Initial biopsies from 78 patients with original diagnosis of Barrett metaplasia negative for dysplasia and a mean follow-up of 72 months were reviewed and reclassified into 3 categories: (1) ITGCs, (2) goblet cell mimickers, or (3) neither. Sections from available paraffin blocks were stained with Alcian blue at pH 2.5. The presence of the different types of cells and positive Alcian blue staining were correlated with each other and evaluated for their significance as predictors of progression to dysplasia. RESULTS: Goblet cell mimickers were present in 35 cases and were associated with ITGCs in the same biopsy in 23 (66%) of these cases. Intestinal-type goblet cells were present in 56 cases, and the remaining 10 cases, although called Barrett on the original report, did not show either ITGCs or goblet cell mimickers. Only the presence of ITGCs was associated with significant risk for dysplasia (P = .008). Positive Alcian blue staining was not associated with a significant risk for dysplasia. CONCLUSIONS: Our results indicate that the diagnosis of Barrett metaplasia should be rendered with confidence only when ITGCs are identified on routine hematoxylin-eosin-stained sections.

Atividade residual de herbicidas usados na soja sobre o girassol cultivado em sucessão / Bioactivity of herbicides used to soybean on sunflower crop in succession

O girassol é uma oleaginosa de destaque entre as culturas utilizadas em sucessão à soja na região dos cerrados. No entanto, poucas informações referentes aos efeitos da atividade residual de herbicidas aplicados na soja sobre o desenvolvimento e rendimento do girassol são conhecidas. Visando avaliar a atividade residual de herbicidas, aplicados em pré e pós-emergência na cultura da soja sobre o girassol cultivado em sucessão, foram conduzidos ensaios em campo e em casa de vegetação. No ensaio de campo, foram empregados nove tratamentos (doses em kg de i.a. ha-1): imazaquin (0,161), diclosulam (0,035), sulfentrazone (0,600) e flumioxazin (0,050), em aplicações de pré-emergência, e chlorimuron-ethyl (0,015), imazethapyr (0,060), imazethapyr (0,100) e fomesafen (0,250), aplicados em pós-emergência da soja, mais uma testemunha (sem herbicida). Um bioensaio foi conduzido em casa de vegetação com as amostras de solo dos tratamentos coletadas em seis épocas distintas (0, 35, 70, 105, 140 e 200 dias após a aplicação). Os resultados permitem concluir que o imazethapyr (0,100kg ha-1) e o diclosulam (0,035kg ha-1) causam redução no rendimento do girassol. A sensibilidade ao diclosulam perdura durante todo o cultivo do girassol.

The sunflower is a oilseed crop kind of prominence before the cultures used in succession in the Brazil. However, little information concerning the effects of residual activity of herbicides on the crop in this region are known. The aim of this study was to evaluate the residual activity of herbicides in weed management in pre and post-emergence soybean and evaluate its effects on sunflower crop in succession. In field experiments we adopted the randomized block design with four replications, being appointed nine treatments (kg of i.a. ha-1): imazaquin (0.161), diclosulan (0.035), sulfentrazone (0.600) and flumioxazin (0.050) in pre emergence applications, and chlorimuron-ethyl (0.015), imazethapyr (0.060), imazethapyr (0.100) and fomesafen (0.250) applied post emergence soybean and a control without herbicide. One bioassay was differentiated by the treatments contained in each treatment and soil samples collected at six different times (0, 35, 70, 105, 140 and 200 days after application); evaluated the dry matter accumulation of sunflower plants as a function of time of sample collection. The results showed that: imazethapyr (0.1kg ha-1) and diclosulan (0.035kg ha-1) caused a reduction in sunflower yield. Sensitivity to diclosulan continued throughout the interval evaluation of the range of bioassay.

Selectivity of preemergence herbicide treatments for cotton crop / Seletividade de herbicidas aplicados em pre-emergencia na cultura do algodoeiro

The use of preemergence herbicides in cotton crop is one of the main tools in weed control. However, little is known about the effects of different herbicide tank mixtures on this crop. Therefore, this work was aimed at evaluating the selectivity of herbicides applied isolated or in mixtures to cotton at preemergence. Herbicide treatments included alachlor, s-metolachlor, diuron, prometryn, trifluralin, oxyfluorfen, alachlor+diuron, alachlor+prometryn, s-metolachlor+diuron, s-metolachlor+prometryn, oxyfluorfen+diuron, oxyfluorfen+prometryn, trifluralin+diuron, trifluralin+prometryn, trifluralin+oxyfluorfen. Herbicide treatments did not affect cotton stand. Oxyfluorfen, isolated or in mixture with diuron, prometryn, and trifluralin caused more significant crop injuries than all the other herbicide treatments. However, only oxyfluorfen+diuron, and trifluralin+oxyfluorfen decreased crop yield, and are regarded as presenting lower selectivity to cotton, cv. Delta-Opal.

O uso de herbicidas em pré-emergência da cultura do algodoeiro é uma das principais ferramentas no controle de plantas daninhas. Entretanto, pouco se conhece sobre os efeitos de misturas em tanque de diferentes produtos nessa cultura. Dessa forma, este trabalho teve por objetivo avaliar a seletividade de herbicidas aplicados em préemergência, isolados ou em misturas, na cultura do algodão. Os tratamentos testados foram compostos dos seguintes herbicidas e suas respectivas doses (g a.i. ha-1): alachlor (1440), S-metolachlor (768), diuron (1500), prometryn (1500), trifluralin (1800), and oxyfluorfen (192) aplicados isoladamente, e em mistura formando os seguintes tratamentos: alachlor+diuron (1440+1500), alachlor+prometryn (1440+1500), S-metolachlor+diuron (768+1500), Smetolachlor+prometryn (768+1500), oxyfluorfen+diuron (192+1500), oxyfluorfen+prometryn (192+1500), trifluralin+diuron (1800+1500), trifluralin+prometryn (1800+1500), e trifluralin+oxyfluorfen (1800+192). O experimento foi conduzido por meio de testemunhas duplas. Foram realizadas avaliações relacionadas à fitointoxicação visual, altura de planta, número de maçãs e produção de algodão em caroço. Os tratamentos herbicidas não influenciaram o estande da cultura do algodoeiro. O herbicida oxyfluorfen isolado ou em mistura com diuron, prometryn e trifluralin proporcionaram maior fitointoxicação à cultura em relação aos demais tratamentos. Entretanto, somente oxyfluorfen + diuron e trifluralin + oxyfluorfen apresentaram rendimento inferior à testemunha, sendo considerados, portanto, de baixa seletividade para o cultivar Delta-Opal.