bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hitting bacteria at the heart of the central dogma: sequence-specific inhibition
Authors: Rasmussen Louise Carøe Vohlander , Sperling-Petersen Hans Uffe , Mortensen Kim Kusk 
Published: August 2007

Abstract
An important objective in developing new drugs is the achievement of high specificity to maximize curing effect and minimize side-effects, and high specificity is an integral part of the antisense approach. The antisense techniques have been extensively developed from the application of simple long, regular antisense RNA (asRNA) molecules to highly modified versions conferring resistance to nucleases, stability of hybrid formation and other beneficial characteristics, though still preserving the specificity of the original nucleic acids. These new and improved second- and third-generation antisense molecules have shown promising results. The first antisense drug has been approved and more are in clinical trials. However, these antisense drugs are mainly designed for the treatment of different human cancers and other human diseases. Applying antisense gene silencing and exploiting RNA interference (RNAi) are highly developed approaches in many eukaryotic systems. But in bacteria RNAi is absent, and gene silencing by antisense compounds is not nearly as well developed, despite its great potential and the intriguing possibility of applying antisense molecules in the fight against multiresistant bacteria. Recent breakthrough and current status on the development of antisense gene silencing in bacteria including especially phosphorothioate oligonucleotides (PS-ODNs), peptide nucleic acids (PNAs) and phosphorodiamidate morpholino oligomers (PMOs) will be presented in this review.
Effects of steroidal and nonsteroidal aromatase inhibitors on markers of bone turnover in healthy postmenopausal women
Authors: Goss Paul E , Hadji Peyman , Subar Milayna , Abreu Paula , Thomsen Torben , Banke-Bochita Jose 
Published: August 2007

Abstract
Introduction
In contrast to nonsteroidal aromatase inhibitors, the steroidal aromatase inactivator exemestane does not have detrimental effects on bone in animal models. This study was designed to compare the effects of exemestane with the nonsteroidal aromatase inhibitors anastrozole and letrozole on serum and urine levels of biomarkers of bone turnover in healthy postmenopausal women.

Methods
Changes in the concentrations of bone-turnover markers, estrogens, and lipids were assessed after daily administration of exemestane (25 mg), letrozole (2.5 mg), anastrozole (1 mg), or placebo for 24 weeks in healthy postmenopausal women. The primary end point was the percentage change from baseline in bone-turnover-marker levels at week 24. The baseline-adjusted area under the curve (AUC) for weeks 0–12 and 0–24 was calculated to evaluate changes in bone turnover over time, rather than at discrete time points.

Results
Seventy-four (88%) of 84 randomized subjects were evaluable for bone-marker assays. Reductions in plasma estrogen levels and increases in bone-resorption markers were comparable for each aromatase inhibitor. Uniquely, exemestane consistently increased the percentage change from baseline in the level of serum procollagen type I N-terminal propeptide (PINP), a marker of bone formation, at week 24. In the active-treatment groups, the baseline-adjusted AUC at weeks 0–12 and 0–24 for PINP was significantly greater for exemestane than the other aromatase inhibitors.

Conclusion
Exemestane increased serum levels of the bone-formation marker PINP after 24 weeks, suggesting a specific bone-formation effect related to its androgenic structure. Potential effects on cortical bone and reduced fracture risk must be verified in a comparative clinical trial.
Prevalence of Symptomatic Androgen Deficiency in Men
Authors: Araujo Andre B. , Esche Gretchen R. , Kupelian Varant , O’Donnell Amy B. , Travison Thomas G. , Williams Rachel E. , Clark Richard V. , McKinlay John B. 
Published: August 2007

Abstract
Context: Despite recognition that androgen deficiency in men should be defined according to biochemical and clinical criteria, most prevalence estimates are based on low testosterone levels alone.
Objective: The objective of this study was to examine the association between symptoms of androgen deficiency and low total and calculated free testosterone levels and estimate the prevalence of symptomatic androgen deficiency in men.
Design: This study was a population-based, observational survey.
Participants: A total of 1475 Black, Hispanic, and white men, between the ages of 30–79 yr, with complete data on testosterone, SHBG, and symptoms of androgen deficiency, and who are not taking medications that impact sex steroid levels were randomly selected from the Boston Area Community Health Survey.
Outcome: Outcomes were measured as symptomatic androgen deficiency, defined as low total (&lt;300 ng/dl) and free (&lt;5 ng/dl) testosterone plus presence of low libido, erectile dysfunction, osteoporosis or fracture, or two or more of following symptoms: sleep disturbance, depressed mood, lethargy, or diminished physical performance.
Results: Mean age of the sample was 47.3 ± 12.5 yr. Approximately 24% of subjects had total testosterone less than 300 ng/dl, and 11% of subjects had free testosterone less than 5 ng/dl. Prevalence of symptoms were as follows: low libido (12%), erectile dysfunction (16%), osteoporosis/fracture (1%), and two or more of the nonspecific symptoms (20%). Low testosterone levels were associated with symptoms, but many men with low testosterone levels were asymptomatic (e.g. in men 50+ yr, 47.6%). Crude prevalence of symptomatic androgen deficiency was 5.6% (95% confidence interval: 3.6%, 8.6%), and was not significantly related to race and ethnic group. Prevalence was low in men less than 70 yr (3.1–7.0%) and increased markedly with age to 18.4% among 70 yr olds. Projection of these estimates to the year 2025 suggests that there will be as many as 6.5 million American men ages 30–79 yr with symptomatic androgen deficiency, an increase of 38% from 2000 population estimates.
Conclusions: Prevalence of symptomatic androgen deficiency in men 30 and 79 yr of age is 5.6% and increases substantially with age. The aging of the U.S. male population will cause a large increase in the burden of symptomatic androgen deficiency. Future work should address the clinical significance of low testosterone levels in asymptomatic men.
Sorption-Analytic, Microcalorimetric and ab Initio Study of Ion-Exchange Equilibria Involving Mg2+ and Ca2+ Cations on Clinoptilolite
Authors: Tarasevich Yuri I. , Polyakov Valeri E. , Krysenko Dmytro O. , Aksenenko Eugene V. 
Published: August 2007

The exchange equilibrium between Mg2+ and Ca2+ ions and the corresponding microcalorimetric ion-exchange heats were studied on two clinoptilolite (Cli) samples. Using the experimental values of the ion-exchange constants (free energies) and heats (enthalpies), reliable estimates of the entropy were obtained for the direct (Mg2+-Ca2+-Cli) and inverse ion-exchange reactions. It was shown that the sign (negative or positive) of the ion-exchange free energy in the case under study was determined essentially by the entropy constituent of the ion-exchange process. The selectivity of clinoptilolite towards Ca2+ cations rather than to Mg2+ cations was demonstrated. The ab initio calculations undertaken confirmed the experimental results and provided structural information concerning the localisation of ions in the crystalline environment. In particular, it was shown that the 10-membered structural clinoptilolite rings provide favourable positions for hydrated Ca2+ cations. The energy gain of the system arising from the Ca2+-Mg-Cli exchange was -E = 8.0–3.4 kJ/mol depending on the localisation sites for the Ca2+ cations; these values are in acceptable quantitative agreement with experimental data for the exchange enthalpy variation –ΔH = (7.3-8.4) kJ/(g equiv). Data were obtained for the energetics of interaction of Ca2+ and Mg2+ ions with water molecules located in the first and second hydration spheres.
Study of the ZDDP Antiwear Tribofilm Formed on the DLC Coating Using AFM and XPS Techniques
Authors: Haque T. , Morina A. , Neville A. , Kapadia R. , Arrowsmith S. 
Published: August 2007

Abstract
To meet the challenge of the increasing demand of fuel economy, in recent years low friction nonferrous coatings such as diamond-like carbon (DLC) coatings have become very popular for automotive tribo-components. The interaction of lubricant additives, which are designed for ferrous surfaces, with nonferrous coatings is an important issue for the automotive and lubricant industries. The aim of this paper is to establish a link between the evolution of antiwear zinc dialkyl dithiophosphate (ZDDP) tribofilm and the tribological performance of a DLC coating under boundary lubrication conditions. Experiments were performed in a pin-on-plate reciprocating tribotester to produce the tribofilm. Atomic force microscopy (AFM) was used to record high resolution topographical images of the ZDDP films while chemical analysis of the ZDDP tribofilms was performed using X-ray photoelectron spectroscopy (XPS). Results in this study show that the ZDDP tribofilm consists of short chain zinc pyrophosphate (Zn2P2O7) and zinc metaphosphate (ZnOP2O5), and it is formed along the raised portion of the initial marks of the DLC surface.
Fate of atrazine in a grassed phytoremediation system
Authors: Henderson Keri L. , Belden Jason B. , Coats Joel R. 
Published: August 2007

Abstract
Atrazine is a well-known contaminant of surface waters and has been implicated in point-source pollution at agrochemical dealerships in the Midwest. Although the fate of atrazine has been well documented in soil and water, little is known about the fate of this contaminant and its metabolites within a grassed system. In the present study, [U-ring-14C]atrazine was added to soil in closed systems to determine the fate of the parent compound and its metabolites in soil, including degradation and movement into plants and air. Soil was treated with 25 mg/kg [14C]labeled atrazine and allowed to age for 5 d. Four systems then were amended with a mixture of prairie grasses, and the remaining four chambers were maintained as unvegetated controls. Dissipation and distribution of parent compound and metabolites were recorded for 21 d. Plant uptake of [14C]residue was less than 0.5% of applied radioactivity. Approximately 2% of total applied [14C]atrazine was mineralized to [14C]CO2, with no differences between vegetated and unvegetated systems. Mass balance recoveries were 76% for grassed systems and 77.5% for unvegetated controls. Approximately 40% of applied radioactivity remained bound to the soil following extraction. The most prevalent extractable compound detected in the soil was the parent, atrazine; major metabolites in soil were deethylatrazine (DEA) and didealkylatrazine (DDA). Leaf tissue contained concentrations of atrazine and key metabolites, i.e., DEA, DDA, and deisopropylatrazine (DIA), above those allowed in forage grasses by the U.S. Environmental Protection Agency; another key metabolite, hydroxyatrazine, was the most prevalent compound identified in both leaf and root tissue.
Laboratory culturing and selection for increased resistance to cadmium reduce genetic variation in the least killifish,Heterandria formosa
Authors: Athrey N.R. Giridhar , Leberg Paul L. , Klerks Paul L. 
Published: August 2007

AbstractPopulations exposed to environmental contaminants can undergo intense selection pressures, which in turn can lead to a loss of genetic variation. We assessed this loss of genetic variation in the least killifish Heterandria formosa for laboratory populations that had undergone eight generations of selection for an increased resistance to cadmium. Using microsatellite markers, we compared genetic variation between three selection and three control laboratory populations and between these laboratory populations and the source population. Heterozygosity was lower in each selection population than it was in its paired control population, with this difference being statistically significant in two of the three comparisons. This is evidence that adaptation to environmental contaminants can result in an overall loss of genetic variation. Furthermore, the laboratory populations had much lower heterozygosity than did the source population. The latter loss of genetic variation, probably a result of random drift, did not prevent the laboratory populations from showing a strong response to the selection for cadmium resistance. The loss of genetic variation resulting from maintaining populations in the laboratory demonstrates that it is important to maintain a large population size for such populations and that the potential for loss of genetic variation in laboratory populations is taken into consideration in ecotoxicology when extrapolating from laboratory to natural populations.
An algal toxicity database of organic toxicants derived by a closed-system technique
Authors: Tsai Kuo-Pei , Chen Chung-Yuan 
Published: August 2007

Abstract
The current study presents the toxicity data of 90 organic compounds with various modes of actions to Pseudokirchneriella subcapitata. The assessment was conducted using a closed-system technique, and a biomass-type end point based on the cell density was employed. The above toxicity data were compared with test results from ciliate (Tetrahymena pyriformis), water flea (Daphnia magna), fish (Pimephales promelas), and luminescent bacteria (Photobacterium phosphoreum). Satisfactory correlation relationships between toxicity data from algae and other aquatic organisms were found (r2 = 0.66-0.82). Pseudokirchneriella subcapitata revealed considerably higher sensitivity to organic toxicants compared with other organisms. Benzenes, aldehydes, and alkanes also were highly selective to the test alga. In addition, the results show that conventional algal batch tests tend to underestimate the toxicity of organic compounds, except in the case of 4-chlorophenol. Toxicity observed from the closed-system test is approximately 2- to 380-fold higher than that estimated by conventional batch tests. Such a phenomenon can be found in nearly all organic compounds, regardless of the chemical's Henry's law constant. In the risk assessment of chemicals, following the European Union's practice, approximately 30% (7 of 23) of the cases may result in a more strict classification when the batch test is replaced by the closed-system test. More effort therefore is needed to revise the algal toxicity database using the closed-system test method.
Chemical reactivation and aging kinetics of organophosphorus-inhibited cholinesterases from two earthworm species
Authors: Rodríguez-Castellanos Laura , Sanchez-Hernandez Juan C. 
Published: August 2007

Abstract
An in vitro study was conducted to evaluate the ability of pyridine-2-aldoxime methochloride (2-PAM) to recover organophosphorus (OP)-inhibited cholinesterase (ChE) activity of two earthworm species (Eisenia fetida and Lumbricus terrestris). After inhibition of ChE activity by OP pesticides, an alkyl group may be released from the OP-ChE complex. This reaction is termed aging, and the esterase cannot be reactivated either spontaneously or by the action of reactivating agents, such as 2-PAM. We also examined the aging kinetics of OP-inhibited ChE activity to evaluate the suitability of 2-PAM reactivation methodology for field monitoring. A 2-PAM concentration of 5 × 10−4 M was enough to reactivate the OP-inhibited ChE activity after 60 min of incubation at 25°C. Chemical reactivation kinetics followed an exponential rise to a maximum of 70 to 80% of normal enzyme activity when ChEs were inhibited with methyl paraoxon or dichlorvos and up to 60% for the chlorpyrifos-inhibited ChE of E. fetida. The aging rates (ka) of the inhibited ChEs were strongly affected by the OP type, and these rates decreased for both earthworm species in the following order: Methyl paraoxon (ka = 0.023–0.033/h) &gt; dichlorvos (ka = 0.008–0.009/h) &gt; chlorpyrifos oxon (ka = 0.003–0.006/h). In particular, chlorpyrifos-inhibited ChE activity of L. terrestris aged slowly (median aging time, 190 h), which means that chemical reactivation of esterase activity with 2-PAM seems feasible one week after exposure to OP pesticides. We conclude that reactivation of earthworm ChE activity by treatment with 2-PAM is a complementary and specific methodology for assessing exposure to OP pesticides.
Early Treatment to Correct Class III Relations with or without Face Masks
Authors: Godt Arnim , Zeyher Claudia , Schatz-Maier Dorothee , Göz Gernot 
Published: August 2007

Abstract
Objective: To determine what therapeutic effects can be expected in the case of early treatment of Class III relations with removable appliances with or without face masks.
Materials and Methods: Records available at the university clinic of Tübingen for 41 patients who had undergone early treatment because of prognathic abnormalities were retrospectively evaluated. Lateral cephalograms taken and casts obtained at baseline and at the end of early treatment were included in the analysis. Two treatment strategies were compared. The first group included removable functional orthopedic appliances only (FOA group), while the second group was treated with removable appliances and with face masks mounted on a cemented maxillary expansion appliance (face mask group).
Results: Positive changes were achieved in both groups for overjet (FOA group: +1.3 mm; face mask group: +2.2 mm) and Wits values (FOA group: +0.4 mm; face mask group: 1.7 mm). Moreover, a change in mean ANB values was achieved in the face mask group (+0.9°). The FOA group exhibited a reduction in mandibular angles. Changes in maxillary inclination with reduced inclination angles led to increases in overjet and overbite. The face mask group showed dorsal rotation of the mandible with reduced SNB values (−0.8°).
Conclusion: Early treatment of prognathism is a meaningful option, as demonstrated by the dentoskeletal (and hence functional) improvements observed in the present study.
Effect of Acidulated Phosphate Fluoride and Casein Phosphopeptide–Amorphous Calcium Phosphate Application on Shear Bond Strength of Orthodontic Brackets
Authors: Keçik Defne , Çehreli Sevi Burçak , Şar Çağla , Ünver Bahtiyar 
Published: August 2007

AbstractObjective: To evaluate the effect of a recently introduced prophylactic agent, casein phosphopeptide–amorphous calcium phosphate (CPP-ACP), on shear bond strength of brackets and compare it with the effect of acidulated phosphate fluoride (APF).Materials and Methods: Forty-eight freshly extracted mandibular bovine incisors were used. Teeth were randomly divided into four groups (n = 12) as follows: group 1 served as control, and no pretreatment was performed on the enamel; group 2, enamel was treated with 1.23% APF and CPP-ACP, respectively; group 3, enamel was treated with CPP-ACP; and group 4, enamel was treated with 1.23% APF for 4 minutes. In all groups, brackets were bonded using a conventional acid-etch and bond system (Transbond XT, 3M Unitek, Monrovia, Calif). Bonded specimens were first stored in deionized water at 37°C for 24 hours, subjected to thermal cycling for 1000 cycles, and further stored in distilled water for 6 weeks before debonding procedures. After debonding, teeth and brackets were examined under a stereomicroscope at 10× magnification for any adhesive remaining, in accordance with the modified adhesive remnant index.Results: The shear bond strengths of all experimental groups were significantly higher than that of the control group (P &lt; .01). There was no significant difference between the shear bond strengths of the experimental groups (P &gt; .05).Conclusion: The use of CPP-ACP either alone or combined with APF could be considered as an alternative prophylactic application in orthodontic practice since it did not compromise bracket bond strength.
Efficacy of temozolomide or dacarbazine in combination with an anthracycline for rescue chemotherapy in dogs with lymphoma
Authors: Dervisis Nikolaos G. , Dominguez Pedro A. , Sarbu Luminita , Newman Rebecca G. , Cadile Casey D. , Swanson Christine N. , Kitchell Barbara E. 
Published: August 2007

Abstract
Objective—To compare results of treatment with temozolomide or dacarbazine, in combination with an anthracycline, in dogs with relapsed or refractory lymphoma.
Design—Nonrandomized, controlled clinical trial.
Animals—63 dogs with relapsed or refractory lymphoma.
Procedures—Chemotherapy was administered in 21-day cycles. A combination of temozolomide and an anthracycline (doxorubicin or dactinomycin) was administered to 21 dogs and a combination of dacarbazine and an anthracycline was administered to 42 dogs. Efficacy and toxicoses were assessed.
Results—Thirteen of the 18 (72%) dogs treated with the temozolomide-anthracycline combination and 25 of the 35 (71%) dogs treated with the dacarbazine-anthracycline combination had a complete or partial response. Median duration of response to rescue chemotherapy was 40 days (range, 0 to 217 days) for dogs in the temozolomide group and 50 days (range, 0 to 587 days) for dogs in the dacarbazine group. The incidence of high-grade hematologic toxicoses was significantly higher among dogs in the dacarbazine group than among dogs in the temozolomide group, but the incidence of gastrointestinal tract toxicoses was not significantly different between groups. There were no significant differences between groups in regard to proportion of dogs with a complete or partial response, duration of response to rescue chemotherapy, survival time following rescue chemotherapy, or overall survival time.
Conclusions and Clinical Relevance—Both combinations had promise in the treatment of dogs with relapsed or refractory lymphoma, although administration of temozolomide was more convenient than administration of dacarbazine and caused fewer hematologic toxicoses.
Online identification of Hammerstein systems with B‐spline networks
Authors: Wang Yanjiao , Liu Yiting , Chen Jiehao , Tang Shihua , Deng Muqing 
Published: March 2024

SummaryNonlinear systems widely exist in real‐word applications and the research for these systems has enjoyed a long and fruitful history, including the system identification community. However, the modeling for nonlinear systems is often quite challenging and still remains many unresolved questions. This article considers the online identification issue of Hammerstein systems, whose nonlinear static function is modeled by a B‐spline network. First, the identification model of the studied system is constructed using the bilinear parameter decomposition model. Second, the online recursive algorithms are proposed to find the estimates using the moving data window and the particle swarm optimization procedure, and show that these estimates converge to their true values with a low computational burden. Numerical examples are also given to test the effectiveness of the proposed algorithms.