Structure−Property Relationships in Push−Pull Amino/Cyanovinyl End-Capped Oligothiophenes: Quantum Chemical and Experimental Studies

A series of push-pull chromophores built around thiophene-based pi-conjugating spacers and bearing various types of amino donors and cyanovinyl acceptors have been analyzed by means of UV-vis-NIR, IR, and Raman spectroscopic measurements in the solid state as well as in solution. The intramolecular charge transfer (ICT) of these pi-conjugated systems has also been tested by analyzing the ability of the solute molecules to undergo shifts in their fluorescence emission maxima with increasing solvent polarity. These push-pull oligomers also display an attractive electrochemical behavior since they generate stable species both upon oxidation and reduction. Oxidation mainly involves changes in the electron-rich aminooligothienyl half-part of the molecule and leads to the formation of stable cations. On the other hand, reduction to radical anions and dianions is mainly cyanovinyl-centered but also affects the pi-conjugated electron relay. Density functional theory (DFT) calculations have been carried out to help the assignment of the most relevant electronic and vibrational features and to derive useful information about the molecular structure of these NLO-phores.

Optical, Redox, and NLO Properties of Tricyanovinyl Oligothiophenes: Comparisons between Symmetric and Asymmetric Substitution Patterns

A series of tricyanovinyl (TCV)-substituted oligothiophenes was synthesized and investigated with a number of physical methods including UV/Vis, IR, and Raman spectroscopy, nonlinear optical (NLO) measurements, X-ray diffraction, and cyclic voltammetry. Mono- or disubstituted oligomers were prepared by the reaction of tetracyanoethylene with mono- or dilithiated oligomers. The comparative effects of the symmetric and asymmetric substitutions in the electronic and molecular properties have been addressed. These oligomers display dramatic reductions in both their optical and electrochemical band gaps in comparison with unsubstituted molecules. The analysis of the electronic properties of the molecules was assisted by density functional theory calculations, which are in excellent agreement with the experimental data. TCV substitution influences the energies of the frontier orbitals, especially with respect to the stabilization of LUMO orbitals. X-ray structural characterization of a monosubstituted oligomer exhibits pi-stacking with favorable intermolecular interactions. NLO results agree with the role of the intramolecular charge-transfer feature in the asymmetric samples. These results furthermore exalt the role of conformational flexibility in the disubstituted compounds and reveal an unexpected nonlinear optical activity for symmetric molecules. Regarding the electronic structure, the interpretation of the vibrational data reflects the balanced interplay between aromatic and quinoid forms, finely tuned by the chain length and substitution pattern. The electronic and structural properties are consistent with the semiconducting properties exhibited by these materials in thin film transistors (TFTs).

Cosmetic outcome of breast conservative treatment for early stage breast cancer

PURPOSE

To evaluate the cosmetic outcome of breast conservative therapy and to examine the degree of agreement between the patients' and oncologists' ratings. We also analyze the influence of several factors on cosmesis.

METHODS AND MATERIALS

We retrospectively evaluated 145 patients with primary breast cancer treated by local excision and radiotherapy between January 2000 and May 2001. Cosmetic outcome was evaluated by doctors and patients and was scored as excellent, good, fair or poor.

RESULTS

73% of patients rated cosmesis as excellent or good while the percentage was 71% when rated by radiation oncologists. The degree of cosmesis concordance evaluated by oncologists and patients was low (kappa = 0.3). In our study the variables which significantly influence on the cosmetic outcome were concomitant adjuvant chemotherapy (p = 0.04) and radiation therapy boost, either by electron beam or brachytherapy (p = 0.013).

CONCLUSION

The cosmetic outcome of breast conserving therapy was good. There was a similar rating by the patient and radiation oncologist, but the level of concordance between patients and doctors was low. Factors that significantly influence the cosmesis appear to be concomitant adjuvant chemotherapy and radiation therapy boost.

Uterine sarcomas in breast cancer patients treated with tamoxifen

Tamoxifen (TMX) has been related with the development of uterine sarcomas. Since the first reported case in 1988, 65 TMX-related cases have been referred to. Here we present three new cases of uterine sarcomas in patients with breast cancer treated with TMX and we comment on the outcome of the cases described in the literature. In the past 25 years, 60 uterine sarcomas have been diagnosed and treated in Hospital Clínic. Three patients have previously received TMX 20 mg/day for 3, 5, and 7 years for breast cancer. Uterine sarcoma appeared 5, 5, and 7 years, respectively, after the start of TMX treatment, and all of them had stage I (FIGO) disease. Two patients had a carcinosarcoma and one patient had an adenosarcoma. After treatment, the disease progressed in two patients and the third patient is alive having a follow-up of 42 months. The low incidence of uterine sarcomas makes it difficult to establish a relationship with TMX. Nevertheless, looking at the literature data, 20 mg/day of TMX over 1 year could be enough to develop uterine sarcoma; the sarcoma appears mainly during the first 8 years and seem to behave more aggressively. Although only 65 cases have been reported in the past 14 years, a strict follow-up is necessary in patients with breast cancer receiving TMX therapy.

Efficacy and Safety of Amlodipine

BACKGROUND

This study set out to assess the safety and efficacy of amlodipine in two cohorts of patients who were attended in primary- and specialised-care centres, respectively.

METHODS

Prospective, observational, multicentre pharmacovigilance study including patients aged >18 years who presented with a diagnosis of hypertension (systolic blood pressure [SBP] >or=140 mm Hg and diastolic blood pressure [DBP] >or=90 mm Hg) of >6 months' duration, which was either untreated or uncontrolled, and who were followed up by general practitioners and specialists over a period of 4-6 months.

RESULTS

Of the total of 4277 patients included in the study, 2520 (58.9%) were attended in primary care and 1757 (41.1%) in specialised care. 2982 patients (69.7%) were receiving monotherapy, the rest were receiving combined therapy. Over the course of the study, 308 patients (7.2%) experienced adverse events related to the study drug, mostly mild to moderate in nature. There were 20 serious events, although none was related to the study drug. By the end of the study, 1617 patients (37.8%) had achieved the therapeutic goal (SBP <140 mm Hg and DBP <90 mm Hg), with the greatest degree of control being registered among patients receiving combined therapy compared with monotherapy (38.7% vs 35.7%), and in those treated in a specialised-care setting versus a primary-care setting (43.5% vs 33.8%; p < 0.005).

CONCLUSIONS

Amlodipine was shown to be a well tolerated and effective drug in one in three patients, and achieved the therapeutic goal in a higher proportion of patients at specialised-care centres compared with those in primary care, and in those receiving combined therapy compared with monotherapy.

Mesitylthio-Oligothiophenes in Various Redox States. Molecular and Electronic Views as Offered by Spectroscopy and Theory

A series of alpha,omega-bis(mesitylthio)oligothiophenes of various chain lengths and with different side substitution patterns have been studied in their oxidized states by means of electron absorption and Raman spectroscopies in combination with theory in the framework of the density functional theory. Upon chemical oxidation, stable radical cations, dications, and even radical trications are generated. Longer chain lengths better stabilize higher oxidation states. The tetramer can be easily converted to the dication, and a trication can be obtained for the ethylenedioxy derivative. The alpha,omega-sulfur atoms are actively involved in the formation of the charged species and exert a favorable tuning of their electronic structure. Raman spectra provide experimental evidence of the attainment of quinoidal structures within the conjugated path, initially heteroaromatic, with different extension as a function of the p-doping level.

Anti-inflammatory profile of dehydrocostic acid, a novel sesquiterpene acid with a pharmacophoric conjugated diene

Sesquiterpene acids are natural products that, in contrast with the thoroughly studied sesquiterpene lactones, have received little pharmacological attention. A good source of this class of compounds is Inula viscosa (Asteraceae), a plant with documented anti-inflammatory effects. The present paper gives the results of our investigations on the biochemical mechanisms involved in the anti-inflammatory activity of one such compound, dehydrocostic acid. The most salient findings were that in vitro dehydrocostic acid inhibits leukotriene B(4) production (IC(50)=22 microM), elastase activity (IC(50)=43 microM) and bee venom phospholipase A(2) activity (IC(50)=17 microM). Furthermore, this sesquiterpenoid was effective on some models of acute edema induced by PLA(2) and 12-O-tetradecanoylphorbol 13-acetate (TPA) Comparison of these data with that known for ilicic acid firmly suggests that the presence of a semiplanar ring A is essential for an improved inhibitory activity on inflammatory mediators.

Incisive Structure−Spectroscopic Correlation in Oligothiophenes Functionalized with (±) Inductive/Mesomeric Fluorine Groups: Joint Raman and DFT Study

This paper presents a combined experimental Raman and density functional theory (DFT) study of a series of oligothiophenes with variable pi-core lengths and substituted at the alpha,omega- and beta,beta'-terminal positions with perfluorohexyl, perfluorohexylcarbonyl, perfluoroarene, and cyano groups. The study covers the neutral and the electrochemically oxidized samples. The spectra have been assigned with the help of B3LYP/6-31G** calculations and interpreted by the predictions of effective conjugation coordinate (ECC) theory. Direct relationships between the bond length alternation (BLA) parameters and the Raman wavenumbers of the two most important bands of the spectra have been outlined showing the collective character of their electronic and vibrational properties. It is found that the topology of the thienyl electronic structure is not uniform along the conjugated core with the external rings more aromatic, whereas for the innermost part the pi-electron delocalization is greater and extends with the increment of chain length. Perfluorohexyl substitution finely tunes the electronic properties via negative inductive effects. The beta,beta' isomers exhibit larger conformational distortion, which strongly modifies the mean conjugation length. Oxidation provokes electronic structure quinoidization spreading over the whole system but more marked in the central part of the pi-core. The Raman features associated to quinoidization in the oxidized species have been interpreted in relation to the oligomer core length and the substitution regiochemistry.

Frequency in allergy to proteins of latex in health care workers

OBJECTIVE

The objective of this study is to evaluate allergy prevalence to latex proteins in health care workers at the Laboratory and Surgery Room of Hospital CIMA Chihuahua.

METHODOLOGY AND RESULTS

A thorough clinical chart was recorded for all health care workers studied: hematic biometry, total IgE by ELISA method, specific IgE to latex antigen by ELISA (pharmacy CAP system), cutaneous tests with latex antigen (Aphi de México, Hevea Brasiliensis Biopal Inc. Spoken WA), through scarification, together with histamine and Evans (positive-negative control). The number included is 99 individuals. Specific IgE to latex in 4 cases was positive (4%) and in the cutaneous tests to latex, 24 cases (24%) resulted positive.

CONCLUSIONS

The study reports a prevalence of (4%) when performing the specific IgE to latex and (24%) to the cutaneous test with antigen to total latex. This data allows us to continue evaluating the personnel at risk at the hospital, with better results in the administration of Labor Medicine at this medical institution.

Electronic modulation of dithienothiophene (DTT) as pi-center of D-pi-D chromophores on optical and redox properties: analysis by UV-Vis-NIR and Raman spectroscopies combined with electrochemistry and quantum chemical DFT calculations

In this paper, we study three symmetrical D-pi-D chromophores containing dithieno[3,2-b:2',3'-d]thiophene (DTT) as the pi-center and various donor end moieties, by means of UV-vis-NIR and FT-Raman spectroscopy and in situ spectroelectrochemistry. The compounds display dual redox properties: all exhibited two oxidations and single stable reduction peaks contrarily to the one or two oxidations and none reduction which could be anticipated in view of their chemical structures. We analyze the possible electronic modulation by the pi-conjugated DTT relay in the redox process and electronic coupling between the two electron donor (D) units attached through conjugation to opposite sides of the pi-linker. To this end, the UV-vis-NIR and FT-Raman spectra of the neutral compounds and of the charged species generated upon in situ p- or n-doping have been recorded and interpreted with the help of Density Functional Theory (DFT) calculations. The analysis of the peculiar Raman features of these pi-conjugated chromophores is guided by the formalism of the Effective Conjugation Coordinate (ECC) theory. This research shows that the Raman spectroscopic characterization of this type of D-pi-D structures is a powerful tool to derive information about their pi-conjugational properties in the pristine and doped states.

Prevalence of silent fecal and urinary incontinence in women from the town of Teruel

OBJECTIVES

To study the prevalence of fecal (FI) and urinary incontinence (UI) in women from Teruel (Spain), as well as the clinical conditions associated with these disorders.

METHODS

We studied prospectively women with an age range of 20-64 years who were randomly selected from the population seen in a primary care center because of medical disorders not related to incontinence. Patients with functional or cognitive impairment were excluded. Medical and obstetric antecedents, as well as the type and frequency of incontinence symptoms were collected in a questionnaire.

RESULTS

Out of 115 women, 103 completed the study (mean age: 41+/-12 years range 20-64). UI was present in 34.9% (stress 33%, urge 14%, mixed 47%), FI in 14 (13.6%) (flatus 57%, liquid stools 43%), and 10 (9.7%) displayed both disorders. Age > 42 years and body mass index more or equal of 25 were associated with FI and UI; pregnancy was only associated with UI, but the group of women with more or equal of 2 vaginal deliveries showed a higher frequency of FI (p < 0.05, Chi squared test). In the multivariate analysis, only the presence of UI was associated with FI (OR 6.0; CI 95% 1.7-21). Association of FI and UI was more frequent in women older than 42 years (OR 16.7, CI 95% 1.9-141). No statistical differences were found when smoking, exercise, and type of childbirth were compared between the presence/absence of FI or UI.

CONCLUSIONS

Urinary and fecal incontinence are frequent in women, and the coexistence of both disorders is not uncommon. Age, overweight and parity are associated with the presence of fecal and/or urinary incontinence.

Large Medical Datasets on the Grid

Objective: This paper shows the use of the emerging Grid technology for gathering underused resources that are distributed among a corporate network. The work of these resources is coordinated for facing tasks which are not affordable by the individual usage of each of them.

Methods: This paper shows an application for the projection, using Volume Rendering techniques, of huge medical volumes obtained from CTs and RMIs, adapted to Grid computing.

Results: As a result the article shows the feasibility of the creation of an application based up on Grid technology, which solves problems that cannot be addressed by using common techniques. As an example, the article describes the projection of a huge medical dataset, which exceeds the resources of most common PCs, carried out by taking profit of idle CPU cycles from the computers of an organization.

Conclusions: Grid technology is emerging as a new framework which allows gathering and coordinating resources distributed among a network (LAN or WAN), for addressing problems which cannot be solved through the single use of any of these resources. Medical Imaging is a clear application area for this technology.

The Grid as a healthcare provision tool

OBJECTIVES

This paper presents a survey on HealthGrid technologies, describing the current status of Grid and eHealth and analyzing them in the medium-term future. The objective is to analyze the key points, barriers and driving forces for the take-up of HealthGrids.

METHODS

The article considers the procedures from other Grid disciplines such as high energy physics or biomolecular engineering and discusses the differences with respect to healthcare. It analyzes the status of the basic technology, the needs of the eHealth environment and the successes of current projects in health and other relevant disciplines.

RESULTS

Information and communication technology (ICT) in healthcare is a promising area for the use of the Grid. There are many driving forces that are fostering the application of the secure, pervasive, ubiquitous and transparent access to information and computing resources that Grid technologies can provide. However, there are many barriers that must be solved. Many technical problems that arise in eHealth (standardization of data, federation of databases, content-based knowledge extraction, and management of personal data ...) can be solved with Grid technologies.

CONCLUSIONS

The article presents the development of successful and demonstrative applications as the key for the take-up of HealthGrids, where short-term future medical applications will surely be biocomputing-oriented, and the future of Grid technologies on medical imaging seems promising. Finally, exploitation of HealthGrid is analyzed considering the curve of the adoption of ICT solutions and the definition of business models, which are far more complex than in other e-business technologies such ASP.

Large medical datasets on the Grid

OBJECTIVE

This paper shows the use of the emerging Grid technology for gathering underused resources that are distributed among a corporate network. The work of these resources is coordinated for facing tasks which are not affordable by the individual usage of each of them.

METHODS

This paper shows an application for the projection, using Volume Rendering techniques, of huge medical volumes obtained from CTs and RMIs, adapted to Grid computing.

RESULTS

As a result the article shows the feasibility of the creation of an application based up on Grid technology, which solves problems that cannot be addressed by using common techniques. As an example, the article describes the projection of a huge medical dataset, which exceeds the resources of most common PCs, carried out by taking profit of idle CPU cycles from the computers of an organization.

CONCLUSIONS

Grid technology is emerging as a new framework which allows gathering and coordinating resources distributed among a network (LAN or WAN), for addressing problems which cannot be solved through the single use of any of these resources. Medical Imaging is a clear application area for this technology.

Unstimulated salivary flow rate, pH and buffer capacity of saliva in healthy volunteers

OBJECTIVES

To assess the salivary flow rate, pH, and buffer capacity of healthy volunteers, and their relationships with age, gender, obesity, smoking, and alcohol consumption, and to establish the lower-end value of normal salivary flow (oligosialia).

METHODS

A prospective study was conducted in 159 healthy volunteers (age > 18 years, absence of medical conditions that could decrease salivary flow). Unstimulated whole saliva was collected during ten minutes, and salivary flow rate (ml/min), pH, and bicarbonate concentration (mmol/l) were measured using a Radiometer ABL 520. The 5 percentile of salivary flow rate and bicarbonate concentration was considered the lower limit of normality.

RESULTS

Median salivary flow rate was 0.48 ml/min (range: 0.1-2 ml/min). Age younger than 44 years was associated with higher flow rates (OR 2.10). Compared with women, men presented a higher flow rate (OR 3.19) and buffer capacity (OR 2.81). Bicarbonate concentration correlated with salivary flow rate. The lower-end values of normal flow rate and bicarbonate concentration were 0.15 ml/min and 1.800 mmol/l, respectively. The presence of obesity, smoking, and alcohol consumption did not influence salivary parameters.

CONCLUSIONS

In healthy volunteers, salivary flow rate depends on age and gender, and correlates with buffer capacity. Obesity, smoking, and alcohol use do not influence salivary secretion.

Vibrational and Quantum-Chemical Study of Nonlinear Optical Chromophores Containing Dithienothiophene as the Electron Relay

A series of nonlinear optical (NLO) donor-acceptor (D-A) chromophores containing a fused terthiophene, namely dithienothiophene (DTT), as the electron relay, the same donor group, and acceptors of various strengths, has been investigated by means of infrared and Raman spectroscopies, both in the solid state as well as in a variety of solvents, to evaluate the effectiveness of the intramolecular charge transfer from the electron-donor to the electron-acceptor end groups. The Raman spectral profiles of these NLO-phores measured from their dilute solutions have been found to be rather similar to those of the corresponding solids, and thus their intramolecular charge transfer (ICT) shows very little dependence on the solvent polarity. The experimental results obtained for the DTT-containing NLO-phore with a 4-(N,N-dibutylamino)styryl end group as the donor and a 2,2-dicyanoethen-1-yl end group as the acceptor differ from those previously obtained for two parent "push-pull" chromophores with the same D-A pair but built-up around either a bis(3,4-ethylenedioxythienyl) (BEDOT) or a bithienyl (BT) electron relay. Vibrational spectroscopy shows that DTT is significantly more efficient as an electron relay than BT (which has the same number of conjugated C=C bonds) or BEDOT (which can be viewed as a rigidified version of BT on account of noncovalent intramolecular interactions between heteroatoms of adjacent rings). Density functional theory (DFT) calculations have also been performed on these NLO-phores to assign their main electronic and vibrational features and to obtain information about their structures. An additional merit of these molecular materials was revealed by the infrared spectra of the DTT-based NLO-phores recorded at different temperatures. Thus, spectra recorded between -170 and 150 degrees C did not show any substantial change, indicating that the materials have a high thermal stability, which is of significance for their use as active components in optoelectronic devices.

Spectroscopic and Theoretical Study of the Molecular and Electronic Structures of a Terthiophene-Based Quinodimethane

The UV/Vis, infrared absorption, and Raman scattering spectra of 3',4'-dibutyl-5,5"-bis(dicyanomethylene)-5,5"-dihydro-2,2':5',2"-terthiophene have been analyzed with the aid of density functional theory calculations. The compound exhibits a quinoid structure in its ground electronic state and presents an intramolecular charge transfer from the terthiophene moiety to the C(CN)2 groups. The molecular system therefore consists of an electron-deficient terthiophene backbone end-capped with electron-rich C(CN)2 groups. The molecule is characterized by a strong absorption in the red, due to the HOMO-->LUMO pi-pi* electronic transition of the terthiophene backbone that shifts hypsochromically on passing from the solid state to solution and with the polarity of the solvent. The analysis of the vibrational spectra confirms the structural conclusions and supports the existence of an intramolecular charge transfer. Vibrational spectra in several solvents and as a function of temperature have also been studied. Significant frequency upshifts of the vibrations involved in the pi-electron-conjugated pathway have been noticed upon solution in polar solvents and with the lowering of the temperature. Finally, we propose a quinoid molecule as a reliable structural and electronic model for dication species in doped oligothiophenes or for bipolaron charged defects in doped polythiophene.