bluuebunny/crossref_metadata_2025 huggingface dataset:
Thick Loop Prostatectomy in the Endoscopic Treatment of Benign Prostatic Hyperplasia: Results of a Prospective Randomised Study
Authors: D’Addessi Alessandro , Porreca Angelo , Foschi Nazario , Racioppi Marco
Published: March 2005

Objective: The thick loop is a new device employed for transurethral resection of the prostate (TURP) using the standard resectoscope. The loop is broader and thicker than the standard one, resulting in better hemostasis because of its ability to cut, coagulate and vaporize tissue simultaneously. We evaluated the safety and efficacy of the thick loop device compared with the standard loop. Patients and Methods: 103 patients with symptomatic benign prostatic hyperplasia were randomized to undergo either thick loop (51 patients) or standard loop TURP (52 patients). Patients were considered for surgery with the American Urological Association (AUA) symptom score greater than 7 and a maximum urinary flow rate <15 ml/s. Serum hemoglobin, hematocrit, electrolytes, operative time, prostate resected weight, catheterization time and complications were recorded. Twelve months later, the AUA score, maximum urinary flow rate (Qmax) and postvoiding residual urine volume were evaluated. Results: There were no significant differences between thick and standard loop TURP regarding the operative and catheterization time, prostate resection weight and postoperative levels of hemoglobin, hematocrit and electrolytes. Twelve months after TURP, the AUA score was significantly lower and Qmax greater in the thick loop compared to the standard loop groups. Conclusions: Thick loop TURP is as safe as standard loop TURP with respect to blood loss, operative time and complications. Operating in a virtually bloodless field could allow a more radical TURP and provide an explanation for the better functional results (Qmax and AUA score) obtained by the thick loop resection.
Advantages of Video-Assisted Approach in Detecting Epididymal Anomalies and Treatment of Nonpalpable Testis
Authors: Güvenç B. Haluk , Sözübir Selami , Ekingen Gülşen , Şenel Ufuk
Published: March 2005

In children with a nonpalpable abdominal testis, preoperative localization is very helpful prior to surgical investigation both to reduce the time required and to plan the correct surgical procedure. It is no doubt that laparoscopy is useful in both diagnosis and management of nonpalpable testis. In this study, 15 patients with 17 nonpalpable testes admitted to our clinic in 2 years period were evaluated retrospectively. Ultrasound study was performed in all patients after detailed physical examination. Testicular location, size, and configuration of epididymis were determined by laparoscopy and compared with ultrasound findings. Laparoscopy, in conjunction with ultrasound, permits not only a better localization and anatomy of the testis but is also superior in planning the best choice of management. We believe that the video-assisted inguinal approach is a feasible method in the treatment of nonpalpable testis when compared to pure open surgery.
Fulminant Hepatic Failure Secondary to Metastatic Prostate Cancer
Authors: Boyiadzis Michael , Nam Myung , Dahut William
Published: March 2005

The most common sites of metastatic disease from prostate cancer include the bones, lymph nodes and less commonly the lungs, adrenal glands, brain and kidneys. Acute fulminant hepatic failure secondary to cancer metastasis is rare and has unique clinical presentation. We describe a case of fatal liver failure in a 71-year-old male due to metastases to the liver from a prostatic adenocarcinoma. Thus in patients with metastatic cancer and elevated liver function tests, the possibility of hepatic involvement by the cancer should be considered as a possible cause of hepatic failure.
Change of Proliferation Rate of Corneal Epithelium in the Rabbit with Orthokeratology Lens
Authors: Shin Young Joo , Kim Mee Kum , Wee Won Ryang , Lee Jin Hak , Shin Dong-Bin , Lee Jae Lim , Xu Yong Gen , Choi Si-Whan
Published: March 2005

Objective: To investigate the cell proliferation rate of normal corneal epithelium with extended orthokeratology lens (OKL) wear in comparison with extended rigid gas-permeable (RGP) lens wear. Methods: Twenty-four rabbits were fitted unilaterally with either an OKL or an RGP lens, and the other eye was used as a control. They were injected with 5-bromo-2-deoxyuridine (BrdU) 24 h prior to being sacrificed. The rabbits were sacrificed at 1, 3, 7 and 14 days after lens fitting. The cornea from the superior limbus to the center was taken at 1.0-mm intervals. The BrdU-labeled cells were counted in medium power fields (×200) in each sample using light microscopy. Results: The number of BrdU-labeled cells in the RGP lens group initially increased, but the number decreased in the corneal center and superior limbus by 32 and 8%, respectively, after 14 days. There was no statistically significant change. However, the number of BrdU-labeled cells in the OKL group decreased after 3 days, and the number of BrdU-labeled cells was reduced in the center and superior limbus by 63 and 8%, respectively, after 14 days. The change in proliferation in the corneal center in the OKL-wearing rabbits was statistically significant compared to the control (p < 0.05). Conclusions: Wearing an OKL had a greater effect on the change of the proliferation pattern in the epithelium than wearing an RGP lens, which suggests that the OKL might be less physiologic than the RGP lens is.
Serum Cytokine Receptor Levels in Noninfectious Uveitis
Authors: Torun Necip , Callizo Josep , Orlic Natasa , Scherer Matthias , Hartmann Christian , Pleyer Uwe
Published: March 2005

Purpose: Understanding of the role of cytokines in uveitis may provide new clues to its treatment. Therefore, the purpose of our study was to evaluate systemic cytokine receptor expression in patients with noninfectious uveitis. Method: Serum concentrations of soluble interleukin-2 receptor α (IL-2 s Rα) and soluble tumor necrosis factor receptor-1 (sTNF-R1) were measured in patients with intermediate uveitis (n = 26), posterior uveitis (n = 23) and healthy controls (n = 12) using ELISA. All patients were identified in a consecutive series of 996 uveitis patients who had been diagnosed between 1998 and 2002 and classified according to the recommendations of the International Uveitis Study Group. Inclusion criteria were idiopathic, active intraocular inflammation, uveitis as a primary process and no systemic anti-inflammatory treatment at the time of blood sampling. None of the patients had an underlying systemic disease. Results: Serum concentrations of IL-2 s Rα were significantly increased in patients with posterior (p < 0.005) and intermediate uveitis (p < 0.005) as compared to healthy controls. Similarly, concentrations of sTNF-R1 appeared to be increased in posterior (p < 0.005) and intermediate (p < 0.005) uveitis patients when compared to controls. Conclusions: Our results may suggest that patients with noninfectious uveitis express systemic cytokine receptors such as TNF-R1 and IL-2 Rα, which may have an important role in the immune response of the eye and may lead to new immunomodulatory approaches.
Age-Related Difference in Size of Brain Regions for Song Learning in Adult Male Dark-Eyed Juncos (Junco hyemalis)
Authors: Corbitt Cynthia , Deviche Pierre
Published: March 2005

In seasonally breeding adult male songbirds, the volumes of several song control regions (SCRs) change seasonally in parallel with plasma testosterone (T) levels and decrease following gonadectomy. Testosterone treatment to castrates prevents this decrease, indicating T dependency. During the breeding season, second-year (SY: birds entering their first breeding season) free-ranging male Dark-eyed Juncos (Junco hyemalis) have smaller testes than older (after second-year, ASY: birds entering at least their second breeding season) birds. SY males also have lower plasma T concentrations than ASY males at the beginning of the breeding season. We investigated differences in song structure of the two age groups and the relationship between age differences in gonadal function and SCR sizes. The average number of syllables per song, syllable duration, trill rate, song duration, and variability in song duration were age-independent. Two brain regions that are thought to be involved primarily in song learning and perception were 13 and 18% larger, respectively, in SY than in ASY males, the opposite of what would be expected based solely on reproductive measures (testis mass and cloacal protuberance width). In contrast, the volumes of two regions that directly control song expression did not differ with age. The lack of age-related size differences in regions that are required for song production may indicate that male juncos of all ages have similar brain space requirements for motor production. Where there were size differences, they were restricted to regions primarily controlling vocal behavior acquisition/perception, suggesting that first time breeders need more brain space than experienced breeders to acquire crystallized song and/or acoustically perceive aspects of their environment.
Recombinant human activated protein C upregulates cyclooxygenase-2 expression in endothelial cells via binding to endothelial cell protein C receptor and activation of protease-activated receptor-1
Authors: Horn Sarah , Lang Siegfried , Fukudome Kenji , Nahrup Adriane Schulze , Hoffmann Ursula , Kaden Jens J. , Borggrefe Martin , Haase Karl K. , Huhle Guenter , Brueckmann Martina
Published: March 2005

Prostacyclin (PGI2) has beneficial cytoprotective properties, is a potent inhibitor of platelet aggregation and has been reported to improve microcirculatory blood flow during sepsis. The formation of PGI2 in response to proinflammatory cytokines is catalysed by the inducible cyclooxygenase (COX) isoform COX-2. Recombinant human activated protein C (rhAPC, drotrecogin alfa (activated)) was shown to have multiple biological activities in vitro and to promote resolution of organ dysfunction in septic patients. Whether rhAPC exerts its beneficial effects by modulating prostanoid generation is unknown up to now. It was therefore the aim of the study to examine the in vitro effect of rhAPC on COX-2-mRNA-expression and PGI2 release from human umbilical vein endothelial cells (HUVEC). We found that rhAPC, at supra-therapeutical concentrations (500ng/ml-20μg/ ml), upregulated the amount of COX-2-mRNA in HUVEC at t=3–9h and caused a time- and dose-dependent release of 6-keto PGF1α, the stable hydrolysis product of prostacyclin. RhAPC further increased the stimulating effect of tumor necrosis factor-α (TNF-α) and thrombin on COX-2-mRNA-levels. Transcript levels of cyclooxygenase-1 (COX-1) and prostagland-in I2 synthase, however, were unaffected by the stimulation with rhAPC or thrombin. The upregulatory effect on COX2-mRNA levels was specific for rhAPC since the zymogen protein C in equimolar concentrations had no effect on COX-2-mRNA-levels or 6keto PGF1α-release. Western Blot analysis revealed an increase of COX-2-protein content in HUVEC after treatment with rhAPC. As shown by experiments using monoclonal antibodies against the thrombin receptor PAR-1 (mAb=ATAP2) and against the endothelial protein C receptor (EPCR; mAb=RCR-252), the effect of rhAPC on COX-2-mRNA up-regulation was mediated by binding to the EPCR-receptor and signaling via PAR-1. These results demonstrate that induction of COX-2-expression is an important response of HUVEC to stimulation with rhAPC and may represent a new molecular mechanism, by which rhAPC promotes upregulation of prostanoid production in human endothelium.
Dietary polyphenols and regulation of gelatinase expression and activity
Authors: Dell’Agli Mario , Canavesi Monica , Galli Germana , Bellosta Stefano
Published: March 2005

The interaction of cells with the extracellular matrix (ECM) is critical for the normal development and function of organisms. The matrix metalloproteinases (MMPs) are a family of Zn++ and Ca++ dependent endopeptidases, which are key mediators of ECM remodelling. The turnover and remodelling of ECM must be tightly regulated, since uncontrolled proteolysis would contribute to abnormal development and to the generation of many pathological conditions characterized by either excessive degradation, or lack of degradation of ECM components. In particular, the gelatinases (MMP-2 and –9) are abundantly expressed in various malignant tumors, play an active role in angiogenesis, and may also influence the process of atherosclerotic lesion formation. In recent years, much consideration has been given to the role of diet in preventing degenerative diseases, such as cancer and cardiovascular diseases. Polyphenols are abundant components/micronutrients of the human diet that have been shown in vitro to profoundly affect ECM turnover by regulating gelatinases expression and activity, acting at both the pre- and post-transcriptional level. Therefore, they could have a beneficial effect in many pathological conditions implicated in connective tissue destruction and remodelling associated with degenerative diseases.
Comments on “Turbulence Closure, Steady State, and Collapse into Waves”
Authors: Kantha Lakshmi H.
Published: March 2005

Two-equation models are being increasingly used to model turbulence in geophysical flows. A salient aspect of these flows is the stable gravitational stratification, which implies that turbulent fluctuations can generate internal waves that drain energy from turbulent eddies. This energy is not available for mixing, and therefore this transfer of energy from turbulence to internal waves has strong implications to mixing in the atmospheric boundary layer and the oceanic mixed layer. How to parameterize energy leakage to internal waves in turbulence models has been the subject of many studies, most recently by Baumert and Peters. This comment is an attempt to critique their work and to explore alternative options.
Multiple Impacts of the Built Environment on Public Health: Walkable Places and the Exposure to Air Pollution
Authors: Frank Lawrence D. , Engelke Peter
Published: March 2005

While considerable attention has been paid to the public-health-related impacts of air pollution, relatively little research has been done to understand how other aspects of the built environment impact health. Americans are increasingly sedentary; erstwhile the rate of increase in obesity is alarming. New research suggests that increased auto dependence, and limited opportunities to walk for utilitarian purposes, has contributed to this emerging obesity epidemic. Within sociodemographic strata, land use patterns and transportation investments collectively shape the desire to walk, drive, or to travel via other means. Mixed use and more compact community designs show significant promise for the promotion of physical activity and the reduction of regional air pollution levels. Opportunities exist to increase physical activity and improve regional air quality through more compact development. However, increased compactness, or density, often exacerbates traffic congestion and can increase exposure of harmful emissions within central areas. Therefore, strategies to reduce localized air pollution in existing and developing centers are required to enable larger health benefits from smart growth to be realized.
Dementia Caregiving: The Experiences of Hispanic/Latino Caregivers
Authors: Neary Susan R. , Mahoney Diane Feeney
Published: March 2005

The purpose of this study was to explore the phenomenon of dementia caregiving in an ethnically diverse group of Latino caregivers, with the goal of identifying cultural influences on the caregiving experience. This qualitative, descriptive, cross-sectional study used Leininger’s ethnonursing approach. There were more similarities than differences in this multiethnic sample of Latino caregivers in understanding of dementia symptoms, beliefs about the caregiving role, and in the factors affecting ongoing care. A lack of knowledge about dementia, rather than culturally influenced beliefs, was the major deterrent to recognition of initial symptoms. Participants viewed family-centered home care as a culturally embedded value but were willing to consider placement when home care became impractical. Providers need to understand the ways in which caregivers must negotiate the tension between cultural beliefs and the demands of their individual circumstances.
Cultural Affiliation and Mammography Screening of Chinese Women in an Urban County of Michigan
Authors: Yu Mei-Yu , Wu Tsu-Yin , Mood Darlene W.
Published: March 2005

The aim of this study is to explore the relationship of culturally based attitudes on breast cancer screening behavior of Chinese women currently residing in the United States. This cross-sectional study used a survey instrument that was administered to a consecutive nonprobability sample of 202 Chinese women residing in an urban Michigan county. Mood’s strength of cultural affiliation scale (SCAS) was modified for cultural appropriateness prior to being translated into Chinese, back-translated, and pretested prior to use for this study. Data were analyzed using descriptive, correlational, and multivariate analysis techniques. Statistical analyses revealed that cultural diversity within the Chinese sample was associated with differing health behaviors and that the SCAS had indirect effects, through access to health care, on women’s mammography screening use (R2 = 28.3%). These study’s findings reveal that cultural affiliation and beliefs are related to the breast cancer screening behavior of immigrant Chinese women.
α‐Tocopherol and Endothelial Nitric Oxide Synthesis
Authors: HELLER REGINE , WERNER‐FELMAYER GABRIELE , WERNER ERNST R.
Published: March 2005

Abstract: Nitric oxide (NO), a central regulator of vascular tone and homeostasis, is generated upon activation of endothelial NO synthase (eNOS), which is mediated by an increase of intracellular calcium and/or by eNOS phosphorylation. A reduction of NO bioavailability leads to endothelial dysfunction that has been shown to be improved by α‐tocopherol in certain conditions. The underlying mechanisms, however, are not completely clarified. The present study was performed to investigate whether α‐tocopherol is able to affect endothelial NO synthesis. The formation of NO was measured in human umbilical vein endothelial cells using citrulline (coproduct) and cGMP (product of the NO‐activated soluble guanylate cyclase) as indicator molecules. α‐Tocopherol (10‐200 μM, 24 hr) increased ionomycin‐induced citrulline and cGMP formation in intact cells in a concentration‐dependent manner. In parallel, ionomycin‐stimulated phosphorylation of eNOS at serine 1177, known to support enzyme activation, was increased by α‐tocopherol, suggesting that this was the mechanism responsible for enhanced NO formation. The effect of α‐tocopherol was dependent on its hydrophobic structure because it was mimicked by γ‐tocopherol but not by trolox, a hydrophilic derivative of α‐tocopherol. Coincubation with ascorbic acid (100 μM, 24 hr) amplified the effects of α‐tocopherol on eNOS phosphorylation and NO formation, which is possibly related to the regeneration of oxidized α‐tocopherol by ascorbate. Our data suggest that vasoprotective effects of α‐tocopherol in vivo may be related to an increase of NO formation. The effect of α‐tocopherol seems to be dependent on tissue saturation with ascorbic acid, and both vitamins may act synergistically to provide optimal conditions for endothelial NO formation.
Effect of Vitamin E on Gene Expression Changes in Diet‐Related Carcinogenesis
Authors: LUNEC JOSEPH , HALLIGAN EUGENE , MISTRY NALINI , KARAKOULA KATHERINE
Published: March 2005

Abstract: Colorectal cancer (CRC) is responsible for the second highest associated mortality in Western Europe and the United States. Approximately 95% of CRC is sporadic and believed to involve environmental agents and chronic inflammation as causal elements. Several recent studies have suggested a link with diet, in particular, red meat, dietary fats, and low consumption of vegetables. Lipid peroxidation and arachidonic acid metabolism have specifically been implicated in genotoxicity, tumor initiation, and promotion. We have examined the global gene expression profiles (Affymetrix; HU133A) of differentiated vs. undifferentiated colonocytes (CRL‐1807), with and without vitamin E supplementation, while undergoing a lipid peroxidative stress. Malondialdehyde and hydroxynonenal, generated by heating a mixture of linoleic and linolenic acid, caused DNA adduct formation identified by immunofluoresence. We also observed a decreased ability for vitamin E to upregulate detoxifying enzymes against free‐radical peroxidation, with the exception of mitochondrial superoxide dismutase in undifferentiated cells. However, there was an increased ability in undifferentiated, rather than in differentiated, colonic cells to detect DNA damage, initiate cytostasis, and then effect subsequent DNA repair and apoptosis, in the presence of vitamin E. The expression profile implies less genotoxic stress is experienced in vitamin E‐supplemented colonocytes, particularly undifferentiated cells, and points to a mechanism by which dietary supplementation may prevent genotoxic damage and subsequent carcinogenic events in the colon, by both antioxidant and non‐antioxidant‐related mechanisms.
Antiangiogenic Potency of Vitamin E
Authors: MIYAZAWA TERUO , TSUZUKI TSUYOSHI , NAKAGAWA KIYOTAKA , IGARASHI MIKI
Published: March 2005

Abstract: We investigated the antiangiogenic property and mechanism of vitamin E compounds, with particular emphasis on tocotrienol (T3), a natural analogue of tocopherol (Toc). T3 inhibited both the proliferation and tube formation of bovine aortic endothelial cells, with δ‐T3 appearing to have the highest activity. δ‐T3 also reduced the vascular endothelial growth factor (VEGF)‐stimulated tube formation by human umbilical vein endothelial cells. Moreover, δ‐T3 inhibited the new blood vessel formation on the growing chick embryo chorioallantoic membrane (assay for in vivo angiogenesis). Orally administered T3 suppressed the tumor cell‐induced angiogenesis in the mouse dorsal air sac assay. In contrast with T3, Toc showed very weak inhibition. Based on DNA microarray analysis, antiangiogenic effect of T3 was attributable in part to regulation of intracellular VEGF signaling (phospholipase C‐γ and protein kinase C). Our findings suggest that T3 has potential as a therapeutic dietary supplement for preventing angiogenic disorders.
Effect of Concomitant Consumption of Fish Oil and Vitamin E on Production of Inflammatory Cytokines in Healthy Elderly Humans
Authors: WU DAYONG , HAN SUNG NIM , MEYDANI MOHSEN , MEYDANI SIMIN NIKBIN
Published: March 2005

Abstract: A beneficial effect of fish oil in reducing inflammatory and cardiovascular diseases has been suggested. This effect occurs in part through fish oil's inhibition of synthesis of pro‐inflammatory cytokines. Epidemiologic studies have shown a link between increased intake of vitamin E in diet and reduced risk of cardiovascular disease. Since pro‐inflammatory cytokines have been indicated in pathogenesis of cardiovascular diseases, the current study was designed to determine the effect of concomitant consumption of fish oil and vitamin E on interleukin (IL)‐1β, IL‐6, and tumor necrosis factor (TNF)‐α production by peripheral blood mononuclear cells (PBMCs). Healthy elderly subjects consumed fish oil plus different doses of vitamin E for 3 months. The results indicated that, in general, fish oil inhibited production of pro‐inflammatory cytokines and vitamin E did not interfere with this effect of fish oil; rather its supplementation might further contribute to the fish oil‐induced inhibition of these cytokines, in particular at the 200 mg/d dose.
Superreplication of Options on Several Underlying Assets
Authors: Ekström Erik , Janson Svante , Tysk Johan
Published: March 2005

We investigate the conditions on a hedger, who overestimates the (time- and level-dependent) volatility, to superreplicate a convex claim on several underlying assets. It is shown that the classic Black-Scholes model is the only model, within a large class, for which overestimation of the volatility yields the desired superreplication property. This is in contrast to the one-dimensional case, in which it is known that overestimation of the volatility with any time- and level-dependent model guarantees superreplication of convex claims.
Extinction Probability in A Birth-Death Process with Killing
Authors: Van Doorn Erik A. , Zeifman Alexander I.
Published: March 2005

We study birth-death processes on the nonnegative integers, where {1, 2,…} is an irreducible class and 0 an absorbing state, with the additional feature that a transition to state 0 may occur from any state. We give a condition for absorption (extinction) to be certain and obtain the eventual absorption probabilities when absorption is not certain. We also study the rate of convergence, as t → ∞, of the probability of absorption at time t, and relate it to the common rate of convergence of the transition probabilities that do not involve state 0. Finally, we derive upper and lower bounds for the probability of absorption at time t by applying a technique that involves the logarithmic norm of an appropriately defined operator.
Progenitors resume generating neurons after temporary inhibition of neurogenesis by Notch activation in the mammalian cerebral cortex
Authors: Mizutani Ken-ichi , Saito Tetsuichiro
Published: March 2005

The mammalian cerebral cortex comprises six layers of neurons. Cortical progenitors in the ventricular zone generate neurons specific to each layer through successive cell divisions. Neurons of layer VI are generated at an early stage, whereas later-born neurons occupy progressively upper layers. The underlying molecular mechanisms of neurogenesis, however, are relatively unknown. In this study, we devised a system where the Notch pathway was activated spatiotemporally in the cortex by in vivo electroporation and Cre-mediated DNA recombination. Electroporation at E13.5 transferred DNA to early progenitors that gave rise to neurons of both low and upper layers. Forced expression of a constitutively active form of Notch (caNotch)at E13.5 inhibited progenitors from generating neurons and kept progenitors as proliferating radial glial cells. After subsequent transfection at E15.5 of a Cre expression vector to remove caNotch, double-transfected cells, in which caNotch was excised, migrated into the cortical plate and differentiated into neurons specific to upper layers. Bromodeoxyuridine-labeling experiments showed that the neurons were born after Cre transfection. These results indicate that cortical progenitors that had been temporarily subjected to Notch activation at an early stage generated neurons at later stages, but that the generation of low-layer neurons was skipped. Moreover, the double-transfected cells gave rise to upper-layer neurons, even after their transplantation into the E13.5 brain,indicating that the developmental state of progenitors is not halted by caNotch activity.
Dorsoventral patterning of theXenopuseye: a collaboration of Retinoid, Hedgehog and FGF receptor signaling
Authors: Lupo Giuseppe , Liu Ying , Qiu Rong , Chandraratna Roshantha A. S. , Barsacchi Giuseppina , He Rong-Qiao , Harris William A.
Published: March 2005

In the developing spinal cord and telencephalon, ventral patterning involves the interplay of Hedgehog (Hh), Retinoic Acid (RA) and Fibroblast Growth Factor (FGF) signaling. In the eye, ventral specification involves Hh signaling, but the roles of RA and FGF signaling are less clear. By overexpression assays in Xenopus embryos, we found that both RA and FGF receptor (FGFR) signaling ventralize the eye, by expanding optic stalk and ventral retina, and repressing dorsal retina character. Co-overexpression experiments show that RA and FGFR can collaborate with Hh signaling and reinforce its ventralizing activity. In loss-of-function experiments, a strong eye dorsalization was observed after triple inhibition of Hh, RA and FGFR signaling, while weaker effects were obtained by inhibiting only one or two of these pathways. These results suggest that the ventral regionalization of the eye is specified by interactions of Hh, RA and FGFR signaling. We argue that similar mechanisms might control ventral neural patterning throughout the central nervous system.
Comparison of Conducting Polymer Actuators Based on Polypyrrole Doped with BF4−, PF6−, CF3SO3−, and ClO4−
Authors: Zama Tetsuji , Hara Susumu , Takashima Wataru , Kaneto Keiichi
Published: March 2005

Polypyrrole films prepared from aromatic ester solutions of tetrabutylammonium tetrafluoroborate (TBABF4), tetrabutylammonium hexafluorophosphate (TBAPF6), tetrabutylammonium trifluoromethanesulfonate (TBACF3SO3), and tetrabutylammonium perchlorate (TBAClO4) exhibited large electrochemical strain (11.2–14.0%) and stress (10.6–22.0 MPa) when cycled between −0.9 V and +0.7 V vs Ag/Ag+ at 2 mV s−1 and 10 mV s−1, respectively, in an aqueous NaPF6 solution, amongst which PPy-CF3SO3− solely elongated mechanically by 60–100%. It is therefore more suitable for practical artificial muscle devices. Although polypyrrole actuators doped with ClO4− exhibited moderate strains for a decade, a PPy-ClO4− actuator prepared from an aromatic ester solution has showed large electrochemical strain (11.2–13.5%) and stress (12.3–15.2 MPa). When cycled at 100 mV s−1, polypyrrole actuators exhibited approximately twice as large electrochemical stress as those measured at 10 mV s−1, because the PPy strip was kept in the doped state (the weakest state) for a shorter time, and early breakage did not occur to give a larger electrochemical stress. Polypyrrole actuators might not be very stable when showing the maximum performance, but the electrochemical strain remained almost constant up to 100 cycles under moderate conditions, such as being driven at 0.1 Hz.
Optical Properties of Long-range-ordered, High-density Gold Nanodot Arrays Prepared Using Anodic Porous Alumina
Authors: Matsumoto Futoshi , Ishikawa Masahiro , Nishio Kazuyuki , Masuda Hideki
Published: March 2005

Long-range-ordered, high-density gold (Au) nanodot arrays were prepared by vapor deposition using anodic porous alumina as a mask. The optical properties of such arrays were examined. The effects of highly ordered, high density arrangements of Au nanodots on the optical properties were elucidated by the dependences of the wavelength (λmax) of the absorption maximal on the dot height and the refractive index of the solvent in which the Au nanodot arrays were immersed.
Synthesis and Characterization of Water-Soluble Multi-walled Carbon Nanotubes Functionalized with Polycystine
Authors: Wang Tao , Zhao Guang-Chao , Wei Xian-Wen
Published: March 2005

Water-soluble multi-walled carbon nanotubes (MWNTs) functionalized with polycystine were prepared by solid-state polycondensation reaction under the irradiation of the infrared heat lamp, which were characterized by transmission electron microscope, X-ray powder diffractometer, and FT infrared spectroscopy. Its solubility in water was close to 7 mg/mL and no precipitates were observed after one month. This may opens the way to improve the interactions between MWNTs and polymer by the hydrogen bond, the dispersion of MWNTs in composite and the compatibility of MWNTs with biological systems.
Clinical and Radiographic Effects of Enamel Matrix Derivative in the Treatment of Intrabony Periodontal Defects: A 12‐Month Longitudinal Placebo‐Controlled Clinical Trial in Adult Periodontitis Patients
Authors: Rösing Cassiano K. , Aass Anne M. , Mavropoulos Antonios , Gjermo Per
Published: March 2005

Background: This randomized, double‐masked, placebocontrolled clinical trial evaluated the effect of enamel matrix derivative (EMD) on clinical and radiographic parameters of periodontal intrabony defects.

Methods: A split‐mouth design was used in 16 chronic periodontitis patients who had similar defects (≥6 mm of probing depth). Both groups underwent scaling and root planing and were acid‐etched with EDTA. The test sites received the EMD solution and the controls a placebo. Clinical examinations of all 16 patients and radiographs of 14 patients were available at baseline and 6 and 12 months after surgery. Clinical outcomes included probing depth (PD) and clinical attachment level (CAL); radiographic analysis was performed using computerized linear measurements. Intergroup comparisons were performed by paired samples t test, and over time comparisons were made by general linear model (α = 0.05).

Results: A statistically significant improvement over time for PD and CAL and a decrease of the vertical component of the defect was detected in both groups. Comparisons between groups revealed at baseline a mean ± SD value of CAL of 12.93 ± 2.00 and 13.47 ± 2.93 for test and control groups, respectively. These values decreased to 10.92 ± 1.92 and 11.31 ± 1.86 after 12 months for test and control. No statistically significant differences could be observed between groups. PD displayed similar results from 7.57 ± 1.02 and 7.38 ± 1.16 for test and control groups at baseline to 3.40 ± 1.82 and 2.99 ± 1.07 after 12 months. If the data are divided into smokers and non‐smokers, no differences are observed.

Conclusion: Use of EMD did not result in more improvement in clinical and radiographic parameters compared to the placebo. J Periodontol 2005;76:129‐133.
The 22q11.2 deletion in African‐American patients: An underdiagnosed population?
Authors: McDonald‐McGinn Donna M. , Minugh‐Purvis Nancy , Kirschner Richard E. , Jawad Abbas , Tonnesen Melissa K. , Catanzaro Jason R. , Goldmuntz Elizabeth , Driscoll Deborah , LaRossa Don , Emanuel Beverly S. , Zackai Elaine H.
Published: March 2005

Findings associated with the 22q11.2 deletion often include congenital heart malformations, palatal anomalies, immunodeficiency, hypocalcemia, and developmental delay or learning disabilities. Often the clinical suspicion of the diagnosis in a patient with one or more of these findings is heightened based on the presence of a characteristic facial appearance. In our large cohort of 370 patients with the 22q11.2 deletion, we report the under‐representation of African‐Americans in our group, as well as, the paucity of craniofacial dysmorphism in these patients. We note that the absence of the typical facial features may result in decreased ascertainment in this population and, furthermore, may delay the implementation of palliative care, cognitive remediation, and recurrence risk counseling. We, therefore, suggest that the clinician's threshold of suspicion should be lower in African‐American patients. © 2005 Wiley‐Liss, Inc.
Functional shape of the skull in vertebrates: Which forces determine skull morphology in lower primates and ancestral synapsids?
Authors: Preuschoft Holger , Witzel Ulrich
Published: March 2005

In order to determine the extent to which the shape of the synapsid skull is adapted for resisting the mechanical loads to which it is subjected, block‐ or simple plate‐shaped finite‐element models were constructed and loaded with external muscle and bite forces in locations estimated to resemble points of application of these forces. These 2D or 3D finite‐element models were iteratively loaded and modified by removing elements that experience only low stresses, and the resulting morphologies of the models were compared with fossil skulls of synapsids and the skulls of extant mammals. The results suggest that the stress flows in these unspecific models are very similar to the arrangement of bone material in real skulls. Morphological differences between taxa depend on a few a priori conditions: length and position of the tooth rows in relation to the braincase, arrangement of muscles, position of the orbits, and position of the nasal opening. Given these initial conditions, finite‐element analysis consistently reveals the close similarity between stress flows and real skulls. The major difference between mammal‐like reptiles and primates is the size of the braincase. This difference accounts for most of the morphological divergence. The postorbital bar seems to be a constructional element of the skull, rather than a means to protect the eyes. The skull shapes of higher primates are determined mainly by masticatory forces and less by external forces acting on the head. This study demonstrates the utility of finite‐element modeling for testing hypotheses regarding relationships between form and function in vertebrate skulls. © 2005 Wiley‐Liss, Inc.
Finite element analysis in vertebrate biomechanics
Authors: Ross Callum F.
Published: March 2005

This special issue ofThe Anatomical Recordpresents a series of papers that apply the method of finite element analysis (FEA) to questions in vertebrate biomechanics. These papers are salient examples of the use of FEA to test hypotheses regarding structure‐function relationships in complexly shaped biological objects such as skulls and in areas of the skeleton that are otherwise impervious to study. FEA is also a powerful tool for studying patterns of stress and strain in fossil animals and artificial constructs hypothesized to represent ancestral conditions. FEA has been used deductively, to study patterns of growth and development, and to investigate whether skull shapes can be created from amorphous blocks using an iterative approach of loading and removing elements. Several of the papers address methodological issues, such as the relative importance of loading conditions and material properties for generating an accurate model and the validation of models using in vivo strain data. Continuing improvements in model building techniques will make possible increased application of FEA to study the functional effects of variation in morphology, whether through ontogenetic or phylogenetic transformations. © 2005 Wiley‐Liss, Inc.
Lipidic Membranes Are Potential “Catalysts” in the Ligand Activity of the Multifunctional Pentapeptide Neokyotorphin
Authors: Lopes Sílvia C. D. N. , Fedorov Aleksander , Castanho Miguel A. R. B.
Published: March 2005

Neokyotorphin (NKT) is a multifunctional pentapeptide that is involved in biological functions as diverse as analgesia, antihibernatic regulation and proliferation stimulus of tumour cells. The interaction of neokyotorphin with cell membranes is potentially important to all these multiple biological processes since receptor‐mediated processes are thought to be involved in neokyotorphin action. Sargent and Schwyzer proposed in their “membrane catalysis” model that ligands interact with membrane lipids in order to adopt the necessary conformation for cell receptors. We have used fluorescence techniques to study the depth, orientation and extent of incorporation of NKT with model membrane systems (lipidic vesicles). The roles of lipid charge, membrane phase and sterol presence were investigated. The phenolic ring of tyrosine is located in a shallow position in membranes. The extent of partition is less in gel crystalline membranes than in liquid crystalline membranes. Addition of cholesterol causes a reorientation of the tyrosine ring at the interface of lipidic bilayers. Lipidic membranes meet all the conditions required for acting as potential “catalysts” in the ligand activity of the multifunctional pentapeptide NKT, because they modulate the exposure and orientation of the phenolic ring, which is most likely involved in docking to receptors.
Process Intensification by Miniaturization
Authors: Charpentier J.‐C.
Published: March 2005

The progress of basic research in chemical engineering has led to a better understanding of elementary phenomena, and it is now possible to imagine new operating modes of equipment or design novel equipment based on scientific principles. Process intensification refers to complex technologies that replace large, expensive, energy‐intensive equipment or processes with smaller, less costly, more efficient plants, or plants that combine multiple operations into a single apparatus or into fewer devices.
Design of a New Micromixer for Instant Mixing Based on the Collision of Micro Segments
Authors: Nagasawa H. , Aoki N. , Mae K.
Published: March 2005

A new type of micromixer for rapid mixing was developed based on mixing by both kinetic energy and molecular diffusion of fluids. The rapid mixing was realized by the collision of micro segments, which were divided into several streams in the radial, at the center of the mixer. The excellent performance of the developed micromixer was confirmed by examining the Villermaux/Dushman reaction and the precipitation of polymer particles by phase separation. From these results, it was clarified that the rapid mixing was driven by both the breaking of micro segments under a high shear rate and instant molecular diffusion between micro segments. In addition, the mixer had a high throughput and corresponded to a wide range of flow rate ratios of fluids. Thus, it is expected that the proposed design concept for micro mixing will give us an efficient micro processing route in the future.
Mixing and Organic Chemistry
Authors: Bayer T. , Himmler K.
Published: March 2005

Mixing is an important unit operation in the chemical industry. Beside stirred vessels, other mixing devices like static mixers are commonly used today. Over the past years, however, microtechnology has become increasingly important for the optimization of existing and the development of new processes. Especially in chemical engineering, microstructured mixers and heat exchangers have been used to determine the potential of chemical reactions without mass or heat transfer limitations. A lot of different materials and functions are available for microstructured components. First examples of applying such components on an industrial scale have been published. This article describes the potential of microtechnology for chemical process development and presents examples from research, development and production.
Versatile Gas/Liquid Microreactors for Industry
Authors: Chambers R. D. , Fox M. A. , Holling D. , Nakano T. , Okazoe T. , Sandford G.
Published: March 2005

The design, fabrication, use and scale‐out of versatile, multi‐channel gas/liquid microreactors, which are suitable for both laboratory and industrial syntheses, are described. Direct fluorination reactions of diethyl malonate and Meldrum's acid using the new microreactor technology were studied to demonstrate the viability of the device for carrying out gas/liquid processes, particularly when using potentially hazardous materials.
The Application of Microreactors for Small Scale Organic Synthesis
Authors: Watts P. , Haswell S. J.
Published: March 2005

This review article describes how microreactors are being applied to synthetic organic chemistry within the pharmaceutical industry and how microreactors may improve the efficiency of the drug discovery process. This article explores how miniaturization may revolutionize chemical synthesis and demonstrates that products are generated in higher yield and purity compared to the equivalent bulk reactions, in much shorter periods of time.
Microreactor Technology: A Revolution for the Fine Chemical and Pharmaceutical Industries?
Authors: Roberge D. M. , Ducry L. , Bieler N. , Cretton P. , Zimmermann B.
Published: March 2005

50 % of reactions in the fine chemical/pharmaceutical industry could benefit from a continuous process based mainly on microreactor technology. However, the frequent presence of a solid phase still hinders the widespread application of such a technology as a multi‐purpose solution. For small scale and pilot productions, speed in process R&D, as well as the avoidance of scale‐up issues, are the main drivers. On the other hand, for large scale productions, a gain in yield and safety are the main motivations for the use of micoreactor technology. The gain in yield must be significant in order to cope with the increase in capital expenditure associated with the development of a new technology.
Laminar Flow and Heat Transfer in a Periodic Serpentine Channel
Authors: Rosaguti N. R. , Fletcher D. F. , Haynes B. S.
Published: March 2005

The fully developed laminar flow and heat transfer behavior in periodic serpentine circular‐section channels has been studied using computational fluid dynamics (CFD). The serpentine elements are characterised by their wavelength (2 L), channel diameter (d), and radius of curvature of bends (Rc) and results are reported for (3 < L/d < 12.5, 0.525 < Rc/d < 2.25) and Reynolds numbers up to 200. The flow is characterised by the formation of a single pair of Dean vortices after each bend, these being stronger if the bend is in the same direction as the previous bend. The vortices decay downstream of the bends, but, as the Reynolds number is increased, the flow space is increasingly dominated by these vortices. At higher values of Reynolds number (corresponding to a Dean number of about 150), a second pair of vortices develops. For Re > ∼ 200, the flow becomes unsteady. Constant wall heat flux (H2) and constant wall temperature (T) boundary conditions have been examined for a range of fluid Prandtl number (0.7 < Pr < 100). The formation of Dean vortices produces significant heat transfer enhancement relative to flow in a straight pipe, with the effect being greater at higher values of Pr. Pressure drop is also increased but to a lesser extent. The alignment of the flow with the vorticity in these structures allows significant mixing of the fluid without creating large pressure‐drop penalties. Dean vortices are also found to inhibit flow separation. These results suggest an effective method for enhancement of heat transfer in deep laminar flows.
New Scopes in Process Design using Microstructured Devices
Authors: Kirschneck D. , Kober M. , Marr R.
Published: March 2005

Microreaction technology offers new opportunities, especially for the production of fine and other speciality chemicals. The area of process design, however, has not been widely reported in literature. Therefore, the aim of the current paper is to give an insight into the necessary steps of industrial process design in microchemical engineering.
Multicomponent Domino Processes Based on the Organocatalytic Generation of Conjugated Acetylides: Efficient Synthetic Manifolds for Diversity‐Oriented Molecular Construction
Authors: Tejedor David , González‐Cruz David , Santos‐Expósito Alicia , Marrero‐Tellado Jose Juan , de Armas Pedro , García‐Tellado Fernando
Published: March 2005

The organocatalytic generation of a strong base by the action of a good nucleophile is the base for the in situ catalytic generation of conjugated acetylides in the presence of aldehydes or activated ketones. The method is affordable in a multicomponent, domino format able to generate a chemically diverse set of multifunctionalized adducts that are very well suited for diversity‐oriented molecular construction. The domino process involves a nucleophile as catalyst and a terminal conjugated alkyne (HCCZ) and an aldehyde or activated ketone as building blocks. The chemical outcome of this process changes dramatically as a function of the nucleophile (tertiary amine or phosphine), temperature, stoichiometry, and solvent. These multicomponent domino processes achieve molecular construction with good atom economy and, very importantly, with an exquisite chemo‐differentiating incorporation of identical starting units into the products (nondegenerated chemical output). These properties convert the HCCZ unit into a specific building block for diversity‐oriented molecular construction. Applications to the modular and diversity‐oriented synthesis of relevant heterocycles are discussed. A protocol involving two coupled domino processes linked in a one‐pot manner will be discussed as an efficient synthetic manifold for the modular and diversity‐oriented construction of multisubstituted nitrogen‐containing heterocycles.