bluuebunny/crossref_metadata_2025 huggingface dataset:
Screening of autosomal gene deletions in patients with hypogonadotropic hypogonadism using multiplex ligation‐dependent probe amplification: detection of a hemizygosis for the fibroblast growth factor receptor 1
Authors: Trarbach Ericka Barbosa , Teles Milena Gurgel , Costa Elaine Maria Frade , Abreu Ana Paula , Garmes Heraldo Mendes , Guerra Gil , Baptista Maria Tereza Matias , De Castro Margaret , Mendonca Berenice Bilharinho , Latronico Ana Claudia
Published: May 2009

Objective  Congenital hypogonadotropic hypogonadism with anosmia (Kallmann syndrome) or with normal sense of smell is a heterogeneous genetic disorder caused by defects in the synthesis, secretion and action of gonadotrophin‐releasing hormone (GnRH). Mutations involving autosomal genes have been identified in approximately 30% of all cases of hypogonadotropic hypogonadism. However, most studies that screened patients with hypogonadotropic hypogonadism for gene mutations did not include gene dosage methodologies. Therefore, it remains to be determined whether patients without detected point mutation carried a heterozygous deletion of one or more exons.

Measurements  We used the multiplex ligation‐dependent probe amplification (MLPA) assay to evaluate the potential contribution of heterozygous deletions of FGFR1, GnRH1, GnRHR, GPR54 and NELF genes in the aetiology of GnRH deficiency.

Patients  We studied a mutation‐negative cohort of 135 patients, 80 with Kallmann syndrome and 55 with normosmic hypogonadotropic hypogonadism.

Results  One large heterozygous deletion involving all FGFR1 exons was identified in a female patient with sporadic normosmic hypogonadotropic hypogonadism and mild dimorphisms as ogival palate and cavus foot. FGFR1 hemizygosity was confirmed by gene dosage with comparative multiplex and real‐time PCRs.

Conclusions  FGFR1 or other autosomal gene deletion is a possible but very rare event and does not account for a significant number of sporadic or inherited cases of isolated GnRH deficiency.
Seed banks cause elevated generation times and effective population sizes of Arabidopsis thaliana in northern Europe
Authors: LUNDEMO SVERRE , FALAHATI‐ANBARAN MOHSEN , STENØIEN HANS K.
Published: May 2009

It is commonly found that effective population sizes of natural populations are much smaller than census sizes of plants and animals. However, theoretical studies have shown that factors rarely investigated empirically, like seed banks in plants and diapause in animals, may have profound influence on effective sizes. Here we investigate whether the presence of seed banks can explain the relatively high genetic variability observed in northern European Arabidopsis thaliana populations with small census sizes. We have genotyped three above‐ and below‐ ground cohorts in 27 Norwegian populations using single nucleotide polymorphism markers. Although the populations varied extensively in levels of variability within and between cohorts, standard genetic population measures were comparable to those obtained in previous studies on above‐ground cohorts using microsatellite markers. Estimated effective population sizes are larger for total populations (containing both seed bank and above‐ground cohorts for 1 year) compared to each of the cohorts considered separately. Using a conservative approach, we find that the effective sizes are larger than census sizes of local populations, and that the effective generation time is higher than 1 year (3–4 years, on average), making A. thaliana a perennial semelparous plant at many northern European localities.
Longevity of inoculum production by Diplodia pinea on red pine cones
Authors: Munck I. A. , Stanosz G. R.
Published: May 2009

In summer of 2004, pycnidia of Diplodia pinea were observed on cones of Pinus resinosa that had matured and opened during previous years, but had been retained in canopies of trees at a mature red pine plantation in southern Wisconsin. Surveys during the winter and early summer of three consecutive years (2005–2007) to determine incidence and abundance of D. pinea conidia on cones of different ages in this stand. Cones from each age class consistently bore pycnidia with conidia of D. pinea. Although cones collected in June of the year after their maturation tended to yield more D. pinea conidia than older cones, large numbers of conidia were obtained from cones even 3 years after maturation. Perennial availability of inoculum due to persistence of D. pinea on cones of several ages in the overstory or in adjacent stands should be considered when regenerating red pine in areas where this pathogen is known to be present.
Translating nociceptor sensitivity: the role of axonal protein synthesis in nociceptor physiology
Authors: Price Theodore J. , Géranton Sandrine M.
Published: May 2009

The increased sensitivity of peripheral pain‐sensing neurons, or nociceptors, is a major cause of the sensation of pain that follows injury. This plasticity is thought to contribute to the maintenance of chronic pain states. Although we have a broad knowledge of the factors that stimulate changes in nociceptor sensitivity, the cellular mechanisms that underlie this plasticity are still poorly understood; however, they are likely to involve changes in gene expression required for the phenotypic and functional changes seen in nociceptive neurons after injury. While the regulation of gene expression at the transcriptional level has been studied extensively, the regulation of protein synthesis, which is also a tightly controlled process, has only recently received more attention. Despite the established role of protein synthesis in the plasticity of neuronal cell bodies and dendrites, little attention has been paid to the role of translation control in mature undamaged axons. In this regard, several recent studies have demonstrated that the control of protein synthesis within the axonal compartment is crucial for the normal function and regulation of sensitivity of nociceptors. Pathways and proteins regulating this process, such as the mammalian target of rapamycin signaling cascade and the fragile X mental retardation protein, have recently been identified. We review here recent evidence for the regulation of protein synthesis within a nociceptor’s axonal compartment and its contribution to this neuron’s plasticity. We believe that an increased understanding of this process will lead to the identification of novel targets for the treatment of chronic pain.
Quality of life in group homes and older persons’ homes
Authors: Higgins Laura , Mansell Jim
Published: May 2009

Accessible summary

We wanted to know whether when you get old is it better to live in older people’s homes or a home just for people with intellectual disabilities. To know this could help people choose where they want to live when they get old.

We learnt:

 People who lived in intellectual disability homes did more activities in the home than people who lived in older people’s homes.

 People who lived in intellectual disability homes went out of the home more than people who lived in older people’s homes.

 Where people live when they get older makes a difference to their lives.

Older people with intellectual disabilities sometimes live in older people’s homes rather than homes for people with intellectual disabilities. Little is known about their quality of life in these homes. A non‐equivalent comparison group design was used to compare the quality of life of 59 people in three groups; older people without an intellectual disability living in older people’s homes (n = 20), older people with an intellectual disability living in older people’s homes (n = 19) and older people with an intellectual disability living in intellectual disability homes (n = 20). Data were collected on participant characteristics, adaptive behaviour and three aspects of quality of life; community involvement, participation in domestic living and choice making. The three groups were comparable in terms of gender, ethnicity and additional impairments but the older people without an intellectual disability were older and had more adaptive skills than the other groups. Older people with an intellectual disability experienced better quality of life outcomes in terms of participation in meaningful activity and community access when they lived in intellectual disability homes compared with older people’s homes. It was not possible to achieve reliability on the measure of choice‐making. This study provides some evidence to suggest that older people with an intellectual disability may be best served in intellectual disability homes rather than older people homes and that it is an area of research which needs further exploration.
Lines of action and stabilizing potential of the shoulder musculature
Authors: Ackland David C. , Pandy Marcus G.
Published: May 2009

The objective of the present study was to measure the lines of action of 18 major muscles and muscle sub‐regions crossing the glenohumeral joint of the human shoulder, and to compute the potential contribution of these muscles to joint shear and compression during scapular‐plane abduction and sagittal‐plane flexion. The stabilizing potential of a muscle was found by assessing its contribution to superior/inferior and anterior/posterior joint shear in the scapular and transverse planes, respectively. A muscle with stabilizing potential was oriented to apply more compression than shear at the glenohumeral joint, whereas a muscle with destabilizing potential was oriented to apply more shear. Significant differences in lines of action and stabilizing capacities were measured across sub‐regions of the deltoid and rotator cuff in both planes of elevation (P < 0.05), and substantial differences were observed in the pectoralis major and latissimus dorsi. The results showed that, during abduction and flexion, the rotator cuff muscle sub‐regions were more favourably aligned to stabilize the glenohumeral joint in the transverse plane than in the scapular plane and that, overall, the anterior supraspinatus was most favourably oriented to apply glenohumeral joint compression. The superior pectoralis major and inferior latissimus dorsi were the chief potential scapular‐plane destabilizers, demonstrating the most significant capacity to impart superior and inferior shear to the glenohumeral joint, respectively. The middle and anterior deltoid were also significant potential contributors to superior shear, opposing the combined destabilizing inferior shear potential of the latissimus dorsi and inferior subscapularis. As potential stabilizers, the posterior deltoid and subscapularis had posteriorly‐directed muscle lines of action, whereas the teres minor and infraspinatus had anteriorly‐directed lines of action. Knowledge of the lines of action and stabilizing potential of individual sub‐regions of the shoulder musculature may assist clinicians in identifying muscle‐related joint instabilities, assist surgeons in planning tendon reconstructive surgery, aid in the development of rehabilitation procedures designed to improve joint stability, and facilitate development and validation of biomechanical computer models of the shoulder complex.
Increase of retinal vessel width in ocular hypertensives with timolol therapy
Authors: Schwartz Bernard , Takamoto Takenori , Lavin Philip
Published: May 2009

Abstract. Purpose: The purpose of this study was to determine whether timolol drops compared to placebo drops had a significant effect on retinal vessel width in ocular hypertensives.

Methods: Thirty‐seven ocular hypertensives were randomly assigned to receive placebo or 0.5% timolol drops to both eyes for 18 to 24 months in a double masked clinical trial. Measurements of ocular pressure and retinal vessel width by computerized image analysis from fundus photographs were made at about 3 month intervals for 18 to 24 months of follow‐up.

Results: None of the subjects developed visual field loss when tested with the Goldmann perimeter by kinetic and static means at six month intervals. Subjects treated with the placebo showed no change in ocular pressure and a significant decrease in retinal vessel width over time especially in the right eye. Subjects treated with timolol had an increase in retinal vessel width compared to the placebo group significant especially for the superior temporal vein. Multivariate analyses indicated that the increase of retinal vessel width was not associated mainly with the ocular pressure on treatment or decrease in ocular pressure on treatment.

Conclusion: Timolol treatment was associated with an increase of retinal vessel width. The effect of timolol appears to be related primarily to mechanisms other than the decrease in ocular pressure.
Retinal dystrophies and genetic counselling
Authors: Jay M. , Evans K.
Published: May 2009

ABSTRACT Increased patient demand is leading to a corresponding increase in the need for informed genetic counselling in ophthalmic practice which requires refined diagnosis, and a detailed knowledge of molecular genetics. Accurate assessment of risk and visual potential in prospective children is becoming available for a range of retinal dystrophies allowing for more educated decisions to be made by parents.
The Walker‐Warburg or a new syndrome?
Authors: Baraitser Michael , Dossetor Jonathan , Slaney Sarah , Green Andrew
Published: May 2009

ABSTRACT We present a patient with retinal dysplasia and cerebral dysgenesis, and discuss the relationship of this condition to the Walker‐Warburg syndrome.
Norrie‐Warburg syndrome: Two novel mutations in patients with classical clinical phenotype
Authors: Gal Andreas , Veske Andres , Jojart György , Grammatico Barbara , Huber Bernd , Gu Sumin , del Porto Giuseppe , Senyi Katalin
Published: May 2009

ABSTRACT Norrie‐Warburg syndrome (NWS) is a rare X‐linked disorder characterized by blindness, which is invariable, deafness and mental disturbances, which are present occasionally. We describe here two novel mutations, a missense mutation (C126S) and a 1‐base pair insertion (insT466/T467), together with a recurrent mutation (M1V), found in patients presenting with the classical clinical phenotype of NWS. All three mutations are likely to result in prominent structural changes of the norrin protein.
Results of treatment of amblyopia with a screening program for early detection
Authors: Lennerstrand Gunnar , Rydberg Agneta
Published: May 2009

ABSTRACT The Swedish program for early intervention in children with visual dysfunction, was evaluated with respect to the results of treatment of amblyopia. One hundred and seventy‐two amblyopic children were examined before and at 6, 12 and 18 months after the beginning of treatment. The mean visual acuity of the amblyopic eye was 0.76 and the mean ratio of visual acuity between the two eyes was 0.75 or better in all types of amblyopia. Children with strabismic amblyopia showed slightly poorer treatment results than the other types, in spite of the fact that their amblyopia had been detected earlier than the others. The results attest to the importance of careful screening of monocular visual acuity in all children, which in Sweden occurs at 4 years of age. This provides a good basis for detection and treatment of amblyopia. Only one child in the group had a visual acuity at 0.2 and may therefore be at risk for visual handicap if the better eye should be lost later in life.
Color doppler imaging and plasma levels of endothelin‐1 in low‐tension glaucoma
Authors: Cellini M. , Possati G. L. , Profazio V. , Sbrocca M. , Caramazza N. , Caramazza R.
Published: May 2009

Endothelin‐1 (ET‐1) is a potent vasoconstrictor peptide produced by vascular endothelin cells. There are reports in the literature that ET‐1 plasma levels are raised in low tension glaucoma (LTG). ET‐1 plasma concentration and Color Doppler Imaging (CDI) evaluation in ophthalmic and posterior ciliary arteries were measured in 15 LTG patients and in 15 healthy subjects. The blood flow index recorded for the ophthalmic artery in normal subjects was a PSV of 36.646±6.611 cm/sec with RI of 0.717±0.019 while in the LTG patients it was 32.961±3.045 cm/sec (p<0.003) with RI of 0.789±0.018 (p<0.001).

For the posterior ciliary arteries in the same two groups, we obtained a PSV of 13.878±4.149 cm/sec vs 8.720±1.645 cm/sec (p<0.001) and an RI of 0.679±0.039 vs 0.722±0.024 (p< 0.001).

The plasma ET‐1 level in normal subjects was 1.720±0.174 pg while in LTG patients it was 2.947±0.217 pg (p<0.001).

On the basis of our experience, we think that GON and the visual field damage found in LTG can be attributed to an alteration in the endothelial self‐regulating sections and consequent vascular insufficiency, particularly pronounced in the posterior ciliary arteries which, since it is these that provide the blood supply to the optic nerve head, leads to irreversible functional damage.
Diagnostic and prognostic indices in primary open angle glaucoma: A color doppler study
Authors: Cristini G. , Cellini M.
Published: May 2009

The authors compute a diagnostic (Di) and a prognostic (Pi) index in primary open angle glaucoma. Four groups of patients were studied. Group A consisted of subjects under 50 years of age, group B of subjects over 50 years of age, group C of patients with normal tension glaucoma and group D with high tension glaucoma. All patients underwent color doppler imaging of the ophthalmic, posterior ciliary and choroid arteries. The Di of the choroid vessels were 0.967±0.011 (gp. A), 1.112±0.010 (gp. B), 1.506±0.008 (gp.C) and 2.891±0.083 (gp. D). The Pi of the posterior ciliary arteries were 22.700±1.160 (gp. A), 20.000±0.943 (gp. B), 15.100±0.568 (gp. C) and 12.100±0.083 (gp. D). Confirmation of these data might validate them as a tool for preventing the evolution of glaucomatous optic neuropathy.
Ocular haemodynamics in some subgroups of normal pressure glaucoma
Authors: Galassi F. , Sodi A. , Rossi M. G. , Ucci F. , De Saint Pierre F.
Published: May 2009

The authors studied, by means of Color Doppler Imaging, a group of Normal Pressure Glaucoma subjects. They found some haemodynamic abnormalities in them which differed in the various subgroups. It would seem that, for each NPG subgroup, there are specific physiopathological and clinical features.
Trans‐scleral krypton laser cyclophotocoagulation: Our experience of its use on patients with neovascular glaucoma
Authors: Di Staso S. , Genitti G. , Verolino M. , Sepe M. , Scupola A. , Balestrazzi E.
Published: May 2009

Trans‐scleral cyclophotocoagulation is an efficacious method in neovascular glaucoma (NVG) treatment. We have used it with krypton laser on 12 eyes of 12 patients affected by NVG with algetic symptoms. Six months after treatment, intraocular pressure was down enough for the pain to disappear. Executional simplicity and the possibility of modulating the intensity of the treatment are grounds for the encouragement of the technique's use in NVG.
The influence of diabetes mellitus on primary open angle glaucoma perimetry
Authors: Zucca I. , Tanda A. , Piras V. , Mulas S. , Mureddu E. , Lecis F. , Sulis R. , Palmas M. C. , Fossarello M. , Serra A.
Published: May 2009

We have carried out a study into retinal sensitivity alterations in the course of primary open angle glaucoma to see if their appearance and evolution might be influenced by concomitant diabetes mellitus. The visual field examination (Perimeter Octopus 500 EZ, programme G1) indicated prevalent sensitivity defects in the superior hemifield, both in glaucoma only subjects and in those with diabetes as well. As to the inferior hemifield, a greater, statistically significant, retinal sensitivity defect was found in the inferior temporal quadrant of the left eye in the group of diabetics.
Induced acute ocular hypertension: mode of retinal cell degeneration
Authors: Pescosolido N. , Del Bianco G. , De Feo G. , Madia F. , Risuleo G. , Scarsella G.
Published: May 2009

The effects of experimental hypertension on retinal cells were studied. Evaluation was made of IOP levels and degree of cell damage by cytochemical and DNA analysis, and degeneration modes: necrosis and apoptosis.
The nerve fibre layer in ocular hypertention. Preliminary results
Authors: Marraffa M. , Perfetti S. , Morbio R. , Bonomi L.
Published: May 2009

A group of healthy subjects (IOP < 22 mmHg) and a simple ocular hypertension group (IOP≥22 mmHg) were examined with a view to checking if there were any differences between their nerve fibre layers. Results indicate thinner fibres in the ocular hypertensives significantly correlative with pressure increase. Among the two groups, some corresponding fibre thicknesses were found.
Effects of brimonidine 0.2% on blue‐yellow perimetry of glaucomatous patients
Authors: Mastropasqua L. , Ciancaglini M. , Carpineto P. , Zuppardi E. , Falconio G. , Gallenga P. E.
Published: May 2009

A cross‐over double‐blind study was performed to evaluate the effect of acute administration of brimonidine on the blue‐yellow perimetry. Thirty patients with primary open‐angle glaucoma were admitted. After brimonidine administration, IOP and pupil diameter showed a significant reduction (p<0.01) without modification in systolic and diastolic blood pressure. Blue‐on‐yellow perimetry showed a significant reduction in CPSD from 3.81 ±1.60 to 2.71 ±1.92 (p<0.05). This result suggests that brimonidine improves ocular perfusion via a reduction of IOP.
Sympathetic use of latanoprost 0.005% in 30 eyes
Authors: Montrone F. , Macinagrossa G. , Tenerelli F.
Published: May 2009

In this study, the authors report their experience with latanoprost after a year's treatment of patients with various forms of glaucoma at various stages of progression. The new drug was associated also with different beta‐blockers. The case file reported includes 30 eyes of 18 patients treated with latanoprost once a day in the evening. Follow‐up varied from 6 months to 1 year. Except for 2 patients (3 eyes) receiving only latanoprost therapy, all the others received latanoprost in association with their on‐going therapy.

Results are equivalent to those described in the literature. The authors also consider the results in two groups; chronic simple glaucoma and other forms of glaucoma. From their own experience and from what is reported in the literature, the authors conclude by stressing the pressure reducing efficacy of this drug.
Fatty acid use in glaucomatous optic neuropathy treatment
Authors: Cellini M. , Caramazza N. , Mangiafico P. , Possati G. L. , Caramazza R.
Published: May 2009

The authors have studied the efficacy of an association of DHA, vitamin E and vitamin B complex (TROFINERV) in glaucomatous patients.

The parameters evaluated were computerized visual field (CVF) and retinal contrast sensitivity (RCS).

Thirty chronic simple glaucoma patients in good tensional compensation with local therapy were given TROFINERV oral therapy. The results show significant differences after 90 days of treatment both in the perimetric indices (MD, SF, CPSD; p<0.05) and in the RCS frequency values (p<0.05).

In the light of the results obtained, the authors consider the use of such association to be a useful support in glaucomatous patient therapy for preventing or delaying the progress of damage.
Early predictors of antisocial developmental pathways among boys and girls
Authors: Pitzer M. , Esser G. , Schmidt M. H. , Laucht M.
Published: May 2009

Objective:  We investigated in a high‐risk sample the differential impact of biological and psychosocial risk factors on antisocial behaviour pathways.

Method:  One hundred and thirty‐eight boys and 155 girls born at differing degrees of obstetric and psychosocial risk were examined from birth until adolescence. Childhood temperament was assessed by a highly‐structured parent‐interview and standardized behavioural observations, adolescent temperament was measured by self‐report. Neurodevelopmental variables were assessed by age‐specific developmental tests. Emotional and behaviour problems were measured at the ages of 8 and 15 by the Achenbach scales.

Results:  In both genders, psychosocial adversity and early self‐control temperament were strongly associated with early‐onset persistent (EOP) antisocial behaviour. Psychosocial adversity and more severe externalizing problems differentiated the EOP from childhood‐limited (CL) pathway. In girls, adolescent‐onset (AO) antisocial behaviour was strongly associated with novelty seeking at 15 years.

Conclusion:  Our findings emphasize the need for early support and intervention in psychosocially disadvantaged families.
How to Make the Japanese Public Pension System Reliable and Workable
Authors: TAKAYAMA Noriyuki , KITAMURA Yukinobu
Published: May 2009

This paper has two objectives. The first is to identify current problems in Japan's pension administration. The chief problem is a weak governance structure. In particular, the current governance structure ignores the role of pension participants. A rigorous division and clear assignment of responsibilities to each of the pension participants, the Social Insurance Agency, and the Ministry of Health, Labor and Welfare is urgently needed. Given rapid demographic change, the second objective is to consider the case for full tax financing of the National Basic Pension. It is estimated that the net burden would vary across different cohorts, but we demonstrate that the net burden can be smoothed across different cohorts. This result is quite different from that in the 2008 Interim Report of the Japanese National Council on Social Security.
Testing a passive tracking index for monitoring the endangered Ethiopian wolf
Authors: EVANGELISTA Paul , ENGEMAN Richard , TALLENTS Lucy
Published: May 2009

The endangered Ethiopian wolf is considered the rarest canid in Africa. The species faces many threats and is particularly vulnerable to diseases such as rabies. A simple, low‐technology means to monitor populations would greatly facilitate conservation efforts, through early detection of population changes and behavior, and signaling a need for intervention. We tested a passive tracking index methodology, which has been a valuable tool for indexing canids and other species around the world. The method uses counts of track intrusions into plots placed in the animals' routes of travel as the basis for calculating an index. Unlike for other species, for which the placement of tracking plots on dirt roads has been extremely successful, we found in our first trial that this approach did not adequately intersect the wolves' activity patterns. The low vegetation associated with Afro‐alpine habitats offered little benefit for the wolves to travel roads. However, in our second trial among molerat colonies, a focus of wolf foraging activity, we found plot placement on molerat mounds was efficient for collecting Ethiopian wolf plot intrusions for index calculations. This plot placement method coupled with the passive tracking index calculations might offer resource managers a cost efficient tool that requires minimal equipment to monitor Ethiopian wolf populations on the Sanetti Plateau and other Afro‐alpine habitats. Plot placement on roads in other Ethiopian wolf habitats where cross‐country travel is more difficult might still be a viable means to collect track data, but would require further testing.
Executive Selection—What's Right … and What's Wrong
Authors: Hollenbeck George P.
Published: May 2009

Although recent reviews of executive selection have catalogued much that we as industrial–organizational (I–O) psychologists are doing right in our research and practice, we are confronted with the facts that executive selection decisions are often, if not usually, wrong and that I–O psychologists seldom have a place at the table when these decisions are made. This article suggests that in our thinking we have failed to differentiate executive selection from selection at lower levels and that we have applied the wrong models. Our hope for the future lies not in job analyses, developing new tests, meta-analyses, or seeking psychometric validity, but in viewing executive selection as a judgment and decision-making problem. With the right focus, applying our considerable methodological skills should enable us to contribute toward making better judgments. When we have a better mousetrap, organizations (if not the world) will beat a path to our door.
Everybody Talks About Organizational Justice, But Nobody Does Anything About It
Authors: Greenberg Jerald
Published: May 2009

Most organizational justice studies focus primarily on theoretical issues and identify implications for practice only in passing. I advocate moving to the next step by testing such implications in theory-based studies that implement and assess the impact of interventions designed to promote organizational justice. Research that promotes organizational justice promises to benefit both organizations and their employees, and may be considered morally appropriate. Although usually not considered in this connection, theory-based application studies also promise to shed light on the theories from which they are derived. Despite these benefits, there are several reasons why such investigations are conducted only rarely. First, because managers tend to be unaware of justice-related problems, they are unlikely to accede to researchers’ requests to address them in research. Second, many researchers erroneously believe that studies assessing ways of improving conditions in organizations lack scientific objectivity. Third, scholarly values favor research that addresses theoretical issues and that eschew practical applications. Finally, the challenges of conducting intervention studies are inclined to be formidable, and these may deter researchers from undertaking such efforts.
Quantitative study on socioeconomic determinants of life expectancy in Beijing, China
Authors: Lei Haichao , Li Liqiu , Liu Xiuying , Mao Ayan
Published: May 2009

Objective To explore the socioeconomic factors associated with life expectancy in Beijing, and to predict future trends.

Methods The linear stepwise regression model was used to construct the relationship between life expectancy and socioeconomic factors.

Results The model showed that there were four factors associated with life expectancy in Beijing. Floor space available per rural resident (P = 0.000) and GDP per capita (P = 0.022) correlated positively with life expectancy, while the rural population proportion (P = 0.010) and illiteracy rate (P = 0.001) correlated negatively with life expectancy.

Conclusion There is a close relationship between life expectancy and socioeconomic factors. The constructed model can be used as a rapid tool to project life expectancy in Beijing. It is possible to improve life expectancy continuously with sustained development of socioeconomic conditions in Beijing, China.
Determination of Composition of Cellulose and Lignin Mixtures Using Thermogravimetric Analysis
Authors: Singh Kaushlendra , Risse Mark , Das K. C. , Worley John
Published: May 2009

The proportional composition of cellulose, hemicellulose, lignin, and minerals in a biomass plays a significant role in the proportion of pyrolysis products (bio-oil, char, and gases). Traditionally, the composition of biomass is chemically determined, which is a time consuming process. This paper presents the results of a preliminary investigation of a method using thermogravimetric analysis for predicting the fraction of cellulose and lignin in lignin-cellulose mixtures. The concept is based on a newly developed theory of pyrolytic unit thermographs (PUTs). The PUT is a thermograph showing rate of change in biomass weight with respect to temperature for a unit weight loss. These PUTs were used as input for two predictive mathematical procedures that minimize noise to predict the fractional composition in unknown lignin-cellulose mixtures. The first model used linear correlations between cellulose/lignin content and peak decomposition rate while the second method used a system of linear equations. Results showed that both models predicted the composition of lignin-cellulose mixture within 7–18% of measured value. The promising results of this preliminary study will certainly motivate further refinement of this method through advanced research.
Gravity Influence of Convective Boiling Stability in a Minichannel
Authors: Brutin David , Tadrist Loune`s
Published: May 2009

We previously evidenced the influence of confinement and inlet conditions on convective boiling stability in a minichannel. The experiments were realized based on an upward n-pentane two-phase flow. Here, we present results of convective boiling in a minichannel for several minichannel orientations which can be modified from the horizontal (heating surface on the top) through the vertical (previous situation already studied of upward flow) to the horizontal (heating surface on the bottom). We present the results obtained for the same heat flux provided to the minichannel (QW = 92 kW.m−2), the same range of inlet mass velocity (73 to 2300 Kg.m−2.s−1) for 5 different minichannel’s orientations: −90°, −45°, 0°, 45° and +90°. The consequences on the minichannel total pressure drop, fluid-wall temperature, and two-phase flow stability are discussed.
Novel Fabrication and Testing of a Bubble-Powered Micropump
Authors: Jung Jung-Yeul , Kwak Ho-Young
Published: May 2009

A bubble-powered micropump was fabricated and tested in this study. The micropump consists of a pair of nozzle-diffuser flow controller and a pumping chamber. The two-parallel micro line heaters were fabricated to be embedded in the silicon dioxide layer above a silicon wafer which serves as a base plate for the micropump. The pumping chamber, the pair of nozzle-diffuser unit and microchannels including the liquid inlet and outlet port were fabricated by etching through another silicon wafer. A glass wafer having two holes of inlet and outlet ports of liquid serve as upper plate of the pump. The sequential photographs of bubble nucleation, growth and collapse were visualized by CCD camera. Clearly liquid flow through the nozzle during the period of bubble growth and slight back flow of liquid at the initial period collapsing can be seen. The mass flow rate was found to be dependent on the duty ratio and the operation frequency. The mass flow rate decreases as the duty ratio increases in the micropump with either circular or square pumping chamber.
Modeling of Two-Phase Flow Instabilities in Microchannels
Authors: Chavan Niranjan S. , Bhattacharya A. , Iyer Kannan
Published: May 2009

This paper addresses a non-dimensional analytical stability model aimed at predicting the occurrence of flow instabilities at micro-scale. In this context, linear stability model using homogenous flow was considered. Towards that, a linear stability model was developed using perturbation method. A characteristic equation (the response of pressure drop to a hypothetical perturbation in inlet velocity) obtained in this analysis, is shown to be a function of sub-cooling number, Zuber number, Froude number, friction number and inlet and outlet restriction coefficients. Then, a neutral dynamic stability curve is obtained using D-Partition approach. Similarly, static or excursive stability curve is also obtained from the characteristic equation. The derived analytical form for static and dynamic instability threshold is represented in the form of simplified correlations. The experimental data reported by other researchers agree well with these correlations. From the results, it is amply clear that for all practical purposes, two-phase cooling will be unstable. The question to be answered in future is, therefore, whether the oscillations that accompany can be tolerated from the application viewpoint.
An Integrated PDMS Microfluidic Device for Dielectrophoretic Separation of Malignant Cells
Authors: Kanagasabapathi Thirukumaran T. , Dalton Colin , Kaler Karan V. I. S.
Published: May 2009

Dielectrophoresis (DEP) has been successfully applied and demonstrated to provide novel and non-invasive means for characterizing, manipulating, trapping, separating and isolating microscopic sized particles, including biological cells. In this article, we report on the design, fabrication and performance of a novel, low cost, integrated Poly(dimethylsiloxane) (PDMS)/DEP microfluidic device capable of controlled manipulation of microscopic sized cells and particles that can be simultaneously utilized both for DEP spectral analysis and cell sorting. We have prototyped microfluidic channels, with DEP microelectrodes incorporated within PDMS channels. Previously, we have evaluated the operation and performance of a prototype device using various dielectric and biological particles, including yeast cells and polystyrene latex beads. In this paper, we report initial experimental observations on malignant cancerous cells. Non-viable cells, due to positive DEP, were attracted to the planar electrodes at frequencies between 200–600 kHz and were clearly repelled from the electrodes, due to negative DEP, at frequencies above 10 MHz.
Steady-State and Transient Performance of a Miniature Loop Heat Pipe
Authors: Chen Yuming , Groll Manfred , Mertz Rainer , Maydanik Yu. F. , Vershinin S. V.
Published: May 2009

A series of tests have been carried out with a miniature loop heat pipe (mLHP), which has been developed for consumer electronics cooling, for horizontal and four vertical orientations under different sink temperatures. The mLHP has a cylindrical evaporator of 5 mm outer diameter and 29 mm length. The steady-state operating characteristics are similar for different orientations except for the orientation where the evaporator is above the compensation chamber. At an evaporator temperature of 75 °C, an evaporator heat load up to 70 W can be reached with thermal resistance of about 0.2 °C/W. The transient behavior of the mLHP is studied in detail. In general, the mLHP can be started up with very low power input (5 W). Big temperature oscillations in the liquid line were found in many cases, however, the temperature oscillations in the evaporator are minimum. The orientations greatly influence the operating characteristics of the mLHP. At least for the horizontal orientation, the overall performance of the tested mLHP is satisfying.
Falling Film Evaporation of Pure Refrigerant HCFC123 in a Vertical Rectangular Minichannel Consisting of Offset Strip Fins
Authors: Ohara Junichi , Koyama Shigeru , Kuwahara Ken
Published: May 2009

In the present study, the characteristics of heat transfer and flow patterns are experimentally investigated on the falling film evaporation of pure refrigerant HCFC123 in a vertical rectangular minichannel consisting of offset strop fins. The refrigerant liquid is supplied to the channel through 37 holes of a distributor. The liquid flowing down vertically is heated electrically from the rear wall of the channel and evaporated. To observe the flow patterns during the evaporation process directly, a transparent vinyl chloride resin plate is placed as the front wall. The experimental parameters are as follows: the mass velocity G = 28∼70 kg/(m2s), the heat flux q = 20∼50 kW/m2 and the pressure P≈ 100 kPa. It is clarified that the heat transfer coefficient α depends on G and q in the region of vapor quality x ≥ 0.3 while there is little influence of G and q in the region x ≤ 0.3. From the direct observation using a high speed video camera and a digital still camera, flow patterns are classified into five typical ones: plane liquid film, wavy liquid film, liquid film accompanied with dry patch, liquid film accompanied with dripping and liquid film accompanied with mist. Then the relation between heat transfer and flow pattern is clarified. The results of heat transfer characteristics are also compared with some previous correlation equations.
Micro Particle Imaging Velocimetry Measurements in High Aspect Ratio Passive Microfluidic Components
Authors: Chiarot Paul , Sullivan Pierre , Ben Mrad Ridha
Published: May 2009

In this work, micro particle imaging velocimetry (micro-PIV) was performed on the fundamental components of a micro total analysis system. Specifically, high aspect ratio passive valves and mixers were designed, fabricated, and characterized. The components were built using Micralyne Protolyne technology on a glass substrate and operated at reasonably achievable pressures. The flows through the components were analyzed both qualitatively and quantitatively with the goal of developing a more complete understanding of internal device performance. Using the results of the micro-PIV developed velocity fields it was found that the high aspect ratio passive valves are able to perform at reasonably achievable pressures. However, it was determined that the high aspect ratio passive mixers offer limited performance enhancements because of the low Reynolds number flows. The results of this work contribute to the understanding of passive component operation and address some of the challenges associated with developing completely integrated micro total analysis systems that use passive devices.
Numerical Study of the Effect of Inlet Constriction on Bubble Growth During Flow Boiling in Microchannels
Authors: Mukherjee Abhijit , Kandlikar Satish G.
Published: May 2009

Flow boiling through microchannels is characterized by nucleation of vapor bubbles on the channel walls and their rapid growth as they fill the entire channel cross-section. In parallel microchannels connected through a common header, formation of vapor bubbles often results in flow maldistribution that leads to reversed flow in certain channels. The reversed flow is detrimental to the heat transfer and leads to early CHF condition. One way of eliminating the reversed flow is to incorporate flow restrictions at the channel inlet. In the present numerical study, a nucleating vapor bubble placed near the restricted end of a microchannel is numerically simulated. The complete Navier-Stokes equations along with continuity and energy equations are solved using the SIMPLER method. The liquid-vapor interface is captured using the level set technique. The results show that with no restriction the bubble moves towards the nearest channel outlet, whereas in the presence of a restriction, the bubble moves towards the distant but unrestricted end. It is proposed that channels with increasing cross-sectional area may be used to promote unidirectional growth of the vapor plugs and prevent reversed flow.
A New Monolithic Electrokinetic Pump With Bubble-Less Design
Authors: Wang Ping , Chen Zilin , Chang Hsueh-Chia
Published: May 2009

An electrokinetic micro-pump fabricated by a sol-gel process has been designed which can be used as a robust fluid-driving unit on a chip-scale analytical system. An overall monolithic silica matrix with morphology of micron-scaled through pores was formed within 100-μm inner diameter fused silica capillary. This pump utilizes electroosmotic flow to propel liquid solution with no moving parts. The Nafion® house design in the cathode chamber separates the electrolytic bubble interference from flow channels. The maximum flow rate and maximum pressure generated by the pump are 3.0 μL/min and 3.5 atm, respectively, at 6 kV. The flow rate can be controlled in the range 200 nL-3.0 μL/min by adjusting applied electric filed. As the monolith is silica-based, this pump can be used for a variety of fluids, especially for organic solvents such as acetonitrile and methanol, without swelling and shrinking problems. These results indicate that the pump can provide sufficient pressure and flow for micro-total-analysis systems (μTAS).
Development of an Automatic Electrokinetically-Controlled Microfluidic Immunoassay for the Detection of Helicobacter Pylori
Authors: Gao Yali , Hu Guoqing , Lin Frank Y. H. , Sherman Philip M. , Li Dongqing
Published: May 2009

A novel automatic electrokinetically-controlled immunoassay lab-on-a-chip was developed in this paper. The microchip was made of poly(dimethylsiloxane) (PDMS)/glass using photolithography and replica molding. The immunoassay technique using anti-Helicobacter pylori antibody was applied to detect H. pylori protein antigens. Rhodamine-labeled secondary antibody was employed for signal generation. Experiments were first conducted on a straight microchannel to prove the feasibility of an electrokinetically-driven immunoassay. The detection limit for the coating antigen was found to be 1 ng/μL. Automatic electrokinetically-controlled immunoassay experiments were further carried out on a microchannel network. Numerical simulation and experimental studies were combined for the first time to demonstrate an integrated, electrokinetically-controlled immunoassay lab-on-a-chip. The electrokinetically driven, time-dependent reagent delivery processes were simulated using finite element method (FEM). Fully automatic on-chip experiments were accomplished by sequentially changing the applied electric field. It was found that the lab-on-a-chip can realize much shorter assay time, reduced reagent consumptions and automation while the detection limit is better than the conventional colorimetric immunoassay.
Effects of Dissolved Air on Subcooled Flow Boiling of a Dielectric Coolant in a Microchannel Heat Sink
Authors: Chen Tailian , Garimella Suresh V.
Published: May 2009

The effects of dissolved air in the dielectric liquid FC-77 on flow boiling in a microchannel heat sink containing 10 parallel channels, each 500 μm wide and 2.5 mm deep, were experimentally investigated. Experiments were conducted before and after degassing, at three flow rates in the range of 30 to 50 ml/min. The dissolved air resulted in a significant reduction in wall temperature at which bubbles were first observed in the microchannels. Analysis of the results suggests that the bubbles observed initially in the undegassed liquid were most likely air bubbles. Once the boiling process is initiated, the wall temperature continues to increase for the undegassed liquid, while it remains relatively unchanged in the case of the degassed liquid. Prior to the inception of boiling in the degassed liquid, the heat transfer coefficients with the undegassed liquid were 300–500% higher than for degassed liquid, depending on the flow rate. The heat transfer coefficients for both cases reach similar values at high heat fluxes (over 120 kW/m2) once the boiling process with the degassed liquid was well established. The boiling process induced a significant increase in pressure drop relative to single-phase flow; the pressure drop for undegassed liquid was measured to be higher than for degassed liquid once the boiling process became well established in both cases. Flow instabilities were induced by the boiling process, and the magnitude of the instability was quantified using the standard deviation of the measured pressure drop at a given heat flux. It was found that the magnitude of flow instability increased with increasing heat flux in both the undegassed and degassed liquids, with greater flow instability noted in the undegassed liquid.
Bubble Characteristics During Boiling in Microchannels
Authors: Liu Jiang-Tao , Tian Yong , Peng Xiao-Feng
Published: May 2009

A series of visualized experiments were conducted to investigate the boiling nucleation and bubble dynamics restricted within parallel microchannels on a silicon chip. The cross-section of each channel was 100 μm (W) × 100 μm (H). A high-speed CCD camera (up to 8,000 fps) was employed together with a microscope to record the boiling process. Under the present experimental conditions, the incipience of boiling was captured. The rates of bubble growth were measured at various flow and heating conditions. The interaction between vapor bubbles, vapor-liquid interface, and solid wall, was analyzed.