A structured jet explains the extreme GRB 221009A

Long-duration gamma-ray bursts (GRBs) are powerful cosmic explosions, signaling the death of massive stars. Among them, GRB 221009A is by far the brightest burst ever observed. Because of its enormous energy (E_iso ≈ 10⁵⁵ erg) and proximity (z ≈ 0.15), GRB 221009A is an exceptionally rare event that pushes the limits of our theories. We present multiwavelength observations covering the first 3 months of its afterglow evolution. The x-ray brightness decays as a power law with slope ≈t^-1.66, which is not consistent with standard predictions for jetted emission. We attribute this behavior to a shallow energy profile of the relativistic jet. A similar trend is observed in other energetic GRBs, suggesting that the most extreme explosions may be powered by structured jets launched by a common central engine.

Different effects on right ventricular function in different etiology of secondary tricuspid regurgitation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Science and Technology, Excutive Yuan, Taiwan

Background

Tricuspid regurgitation (TR) is traditionally classified as primary or secondary TR. The effects of TR on right ventricular (RV) function were not consistent. We hypothesized that secondary TR is not a unique group, sophisticated sub-grouping can be useful for studying effects of TR on RV function.

Methods

207 consecutive patients identified as significant TR (moderate and severe) by echocardiography were recruited. Standard measurements for right heart were done according to guideline. Lateral tricuspid annulus systolic tissue velocity (S’) and RV fractional area change (FAC) were used for RV function. We classified these patients into primary TR and 6 subgroups of secondary TR according to a new systemic approach.

Results

Mean age of subjects was 71.2 ± 14.7 years, and there were 84 (40.6%) male. There were 29 (14%) primary TR. Secondary TR was further classified into 6 groups included 18 (8.7%) pacemaker related, 81 (39.1 %) left heart diseases, 6 (2.9%) congenital heart diseases, 3 (1.4%) RV myopathy, 27 (13.0%) pulmonary hypertension, and 43 (20.8%) idiopathic TR. Among 4 major groups (congenital heart disease and RV myopathy were not included in analysis due to low numbers) of secondary TR, S’ was significant higher in idiopathic TR and RV FAC were higher in pacemaker related and idiopathic TR. RV dysfunction was defined as FAC < 35%. RV dysfunction presented mostly in pulmonary hypertension related TR and leastly in idiopathic TR (59.3% vs. 14%, p <0.001). Multivariate analysis using idiopathic TR as reference and controlled TR maximal velocity, RV end-diastolic area, right atrial area, and severity of TR, left heart disease related TR had higher risk of RV dysfunction (OR 4.178, 95% CI 1.490-11.703, p = 0.007).

Conclusions

Effects of TR on RV function were different among different subgroups of secondary TR. Left heart disease related TR had highest risk for RV dysfunction. Secondary TR should not be regarded as a single disease.

Characteristics of idiopathic tricuspid regurgitation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Science and Technology, Executive Yuan, Taiwan

Background

Tricuspid regurgitation (TR) were traditionally classified as primary and secondary TR. Recently a new category of TR was developed and named as idiopathic TR. However, diagnosis and characteristics of idiopathic TR were not consisted. We tried to identify idiopathic TR by a new systemic approach and studied its characteristics.

Methods

207 consecutive patients (mean age 71.2 ± 14.7 years, 40.6% male) identified as significant TR (moderate and severe) by echocardiography were recruited. We classified TR by a new systemic approach. The classification process started from identified primary TR, then pacemaker related TR, left heart disease related TR, congenital heart related TR, right ventricular (RV) myopathy, pulmonary hypertension and, finally idiopathic TR step by step.

Results

There were 29 (14%) primary TR, 18 (8.7%) pacemaker related, 81 (39.1 %) left heart diseases, 6 (2.9%) congenital heart diseases, 3 (1.4%) RV myopathy, 27 (13%) pulmonary hypertension, and 43 (20.8%) idiopathic TR. Mean age of idiopathic TR was 72.9 ± 11.4 years and 39.5% was male which were not different from other groups. Atrial fibrillation was presented highest in patients with pacemaker related TR (77.8%) and left heart disease (55.6%), lowest in primary TR (24.1%) and pulmonary HT (25.9%), and modest in idiopathic TR (44.2%). Among the echocardiographic characteristics of right heart measurements, idiopathic TR had lowest TR maximal velocity (3.0 ± 0.3 m/s), pulmonary (41.2 ± 8.7 mmHg) and right atrium pressure (5.3 ± 0.3 mmHg; all p <0.001). Idiopathic TR had smallest RV wall thickness (4.5 ± 1.4 mm; p = 0.008), tricuspid annulus diameter (3.2 ± 0.7 cm; p = 0.001), and right atrial area (18.9 ± 8.4 cm2; p <0.001). RV function represented as tricuspid annulus velocity S’ (12.8 ± 3.3 cm/s; p = 0.011) and RV fractional area change FAC (42.6 ± 16.0 %; p <0.001) were best in idiopathic TR. RV dysfunction (FAC < 35%) was lowest (14%) in idiopathic TR.

Conclusions

Idiopathic TR had better RV function then other types of TR. Idiopathic TR can be regarded as a unique disease category in studying TR.

Constraints on Lorentz Invariance Violation from HAWC Observations of Gamma Rays above 100 TeV

Because of the high energies and long distances to the sources, astrophysical observations provide a unique opportunity to test possible signatures of Lorentz invariance violation (LIV). Superluminal LIV enables the decay of photons at high energy. The high altitude water Cherenkov (HAWC) observatory is among the most sensitive gamma-ray instruments currently operating above 10 TeV. HAWC finds evidence of 100 TeV photon emission from at least four astrophysical sources. These observations exclude, for the strongest of the limits set, the LIV energy scale to 2.2×10^{31}  eV, over 1800 times the Planck energy and an improvement of 1 to 2 orders of magnitude over previous limits.

Multiple Galactic Sources with Emission Above 56 TeV Detected by HAWC

We present the first catalog of gamma-ray sources emitting above 56 and 100 TeV with data from the High Altitude Water Cherenkov Observatory, a wide field-of-view observatory capable of detecting gamma rays up to a few hundred TeV. Nine sources are observed above 56 TeV, all of which are likely galactic in origin. Three sources continue emitting past 100 TeV, making this the highest-energy gamma-ray source catalog to date. We report the integral flux of each of these objects. We also report spectra for three highest-energy sources and discuss the possibility that they are PeVatrons.

P1771 Gender differences of the blood pressure effects on early changes of left ventricle mechanics in untreated hypertension

Background

Left ventricular (LV) diastolic dyssynchrony and global and layer-specific strain can be used for evaluation of early myocardial changes in hypertension. We tried to investigate the gender differences in these early changes in untreated uncomplicated hypertension.

Methods

This study included 43 consecutive patients (mean age 51.3 ±12.5 years, 56% men) with newly diagnosed hypertension from an out-patient clinic. All subjects were free of complications including renal dysfunction, LV hypertrophy, and diabetes. Comprehensive transthoracic echocardiography (E9, GE, USA) was conducted before treatment of hypertension. Diastolic and systolic parameters were measured by two-dimension (2D), Doppler, tissue Doppler imaging and 2D speckle tracking echocardiography (STE). The time-to-peak early diastolic myocardial annulus velocity (Te) at 6 LV segments from apical-4-chamber, apical-2-chamber and apical-3-chamber views were measured with reference to the QRS complex. The time to peak early diastolic strain rate (TDSr), global longitudinal strain (GLS), layer-specific longitudinal strain included sub-epicardial strain (EpiLS) and sub-endocardial strain (EndLS) were measured from 18 LV segments by STE. Diastolic dyssynchrony parameters were defined as the standard deviation (SD) of Te of all LV segments (Te-SD), SD of TDSr of 18 LV segments (TDSr-SD), and the maximal difference between any two TDSr of the 18 LV segments (MaxD-TDSr).

Results

There were no differences between men (56%) and women (44%) regarding age, initial blood pressure, hypertension duration, LV mass index, LV ejection fraction, and early mitral velocity to average early annulus velocity ratio. Regarding diastolic dyssynchrony parameters, men were significantly higher than women including Te-SD (22.3 ± 13.8 vs. 14.7 ± 4.2 ms; p = 0.016), TDSrSD (46.0 ± 13.3 vs. 35.3 ± 11.4 ±ms; p = 0.008), and MaxD-TDSr (162.0 ± 40.3 vs. 128.1 ± 50.7 ms; p = 0.019). Men also had worse GLS (-17.6 ± 1.9 vs. -19.5 ± 2.5 %; p = 0.007), EpiLS (-15.1 ± 1.7 vs. -17.0 ± 2.3, p = 0.003), and EndLS (-20.5 ± 2.2 vs. -22.4 ± 2.8 %; p = 0.018) than women. After multivariate analysis controlling age, systolic blood pressure, and LV mass index, TeSD (p = 0.039), TDSrSD (p = 0.018), MaxD-TDSr (p = 0.035) were still significantly higher than women. GLS (p = 0.046), and EpiLS (p = 0.025) were still worse in men.

Conclusion

In the same age, blood pressure, hypertension duration and LV mass index, men have more diastolic dyssynchrony and worse myocardial strain in untreated hypertension.

Publisher Correction: Very-high-energy particle acceleration powered by the jets of the microquasar SS 433

In this Letter, owing to a production error, the penultimate version of the PDF was published. The HTML version was always correct. The PDF has been corrected online.

Preservation of fruit and vegetable discards with sodium metabisulfite

Two series of experiments were performed to investigate the aerobic preservation of fruit and vegetable discards (FVD) using sodium metabisulfite (SMB). In Exp. 1, metabisulfite was applied at 0, 2, 4, 6, and 8 g/kg FVD for 0, 3, 6, 9, and 12 d. Metabisulfite treatment at 6 and 8 g/kg FVD was highly effective in controlling putrefaction and preserving the nutrient components for 6 and 9 d, respectively. In the pilot-scale experiment (Exp. 2), SMB was applied at 0 and 8 g/kg FVD in a 600-L bucket for 0, 6, and 9 d in an outdoor environment. The SMB treatment was highly effective in maintaining the integrity and freshness of FVD, suppressing microbial proliferation, and preserving the nutrient constituents. Under the conditions of this study, SMB effectively preserved FVD in an aerobic environment, enabling their more efficient long-term recycling through livestock feed or development of value-added products.

Extended gamma-ray sources around pulsars constrain the origin of the positron flux at Earth

The unexpectedly high flux of cosmic-ray positrons detected at Earth may originate from nearby astrophysical sources, dark matter, or unknown processes of cosmic-ray secondary production. We report the detection, using the High-Altitude Water Cherenkov Observatory (HAWC), of extended tera-electron volt gamma-ray emission coincident with the locations of two nearby middle-aged pulsars (Geminga and PSR B0656+14). The HAWC observations demonstrate that these pulsars are indeed local sources of accelerated leptons, but the measured tera-electron volt emission profile constrains the diffusion of particles away from these sources to be much slower than previously assumed. We demonstrate that the leptons emitted by these objects are therefore unlikely to be the origin of the excess positrons, which may have a more exotic origin.

Cortical abnormalities in bipolar disorder: an MRI analysis of 6503 individuals from the ENIGMA Bipolar Disorder Working Group

Despite decades of research, the pathophysiology of bipolar disorder (BD) is still not well understood. Structural brain differences have been associated with BD, but results from neuroimaging studies have been inconsistent. To address this, we performed the largest study to date of cortical gray matter thickness and surface area measures from brain magnetic resonance imaging scans of 6503 individuals including 1837 unrelated adults with BD and 2582 unrelated healthy controls for group differences while also examining the effects of commonly prescribed medications, age of illness onset, history of psychosis, mood state, age and sex differences on cortical regions. In BD, cortical gray matter was thinner in frontal, temporal and parietal regions of both brain hemispheres. BD had the strongest effects on left pars opercularis (Cohen's d=-0.293; P=1.71 × 10^-21), left fusiform gyrus (d=-0.288; P=8.25 × 10^-21) and left rostral middle frontal cortex (d=-0.276; P=2.99 × 10^-19). Longer duration of illness (after accounting for age at the time of scanning) was associated with reduced cortical thickness in frontal, medial parietal and occipital regions. We found that several commonly prescribed medications, including lithium, antiepileptic and antipsychotic treatment showed significant associations with cortical thickness and surface area, even after accounting for patients who received multiple medications. We found evidence of reduced cortical surface area associated with a history of psychosis but no associations with mood state at the time of scanning. Our analysis revealed previously undetected associations and provides an extensive analysis of potential confounding variables in neuroimaging studies of BD.

Effective acute care handover to GP: optimising the structure to improve discharge documentation

Time and resource constraints have often led to the use of assessment records as discharge communications from acute and emergency departments. However, whether this addresses the primary care needs has not been demonstrated. This study examined the optimal structure that can impart key discharge information effectively using feedback from general practitioners (GP). We implemented an electronic assessment template that focused on the most relevant headings. Prespecified process measures were examined and qualitative thematic analysis of free-text comments from GP surveys were conducted to optimise the document. Our findings suggest that the structure of a discharge summary can influence the quality of information, users' compliance and readers' perceptions of the length of the letter.

Dynamic Internet-Mediated Team-Based Case Management of High-Frequency Emergency Department Users

Introduction

We assessed whether a strategy using dynamic, internet-mediated, team-based case management could reduce the number of subsequent emergency department (ED) visits by frequent ED users.

Methods

Patients who attended the ED three or more times within 72 hours in June 2010 were identified. These cases were divided into the pain management or chronic disease group according to their chief complaint. Patients were assessed by expert panels, and initial care plans were developed and posted on an internal website. Thereafter, each emergency physician could follow or adjust the care plans dynamically via the internal website according to the patient's condition and use the website to communicate results. Care plans were revised by the team according to the patient's clinical situation as it changed. Patient ED visits over the subsequent six months were monitored.

Results

Fourteen cases were enrolled in the study, seven in each group. The mean number of visits per patient per month in the pain management and chronic disease groups decreased from 14.9 to 5.79 (p=0.031) and 6.1 to 2.9 (p<0.001) visits per month after the intervention, respectively. The overall mean number of visits per patient per month decreased from 10.5 to 4.36 (p=0.004), a decrease of 6.14 visits (58.27%).

Conclusions

Dynamic internet-mediated team-based case management may help to reduce subsequent visits in patients who frequently visit the ED. (Hong Kong j.emerg.med. 2014;21:161-166)

Neural correlates of affective and non-affective cognition in obsessive compulsive disorder: A meta-analysis of functional imaging studies

Obsessive compulsive disorder (OCD) is characterized by intrusive thoughts and repetitive ritualistic behaviors and has been associated with diverse functional brain abnormalities. We sought to synthesize current evidence from functional magnetic resonance imaging (fMRI) studies and examine their alignment to pathogenetic models of OCD. Following systematic review, we identified 54 task-fMRI studies published in the last decade comparing adults with OCD (n=1186) to healthy adults (n=1159) using tasks of affective and non-affective cognition. We used voxel-based quantitative meta-analytic methods to combine primary data on anatomical coordinates of case-control differences, separately for affective and non-affective tasks. We found that functional abnormalities in OCD cluster within cortico-striatal thalamic circuits. Within these circuits, the abnormalities identified showed significant dependence on the affective or non-affective nature of the tasks employed as circuit probes. In studies using affective tasks, patients overactivated regions involved in salience, arousal and habitual responding (anterior cingulate cortex, insula, caudate head and putamen) and underactivated regions implicated in cognitive and behavioral control (medial prefrontal cortex, posterior caudate). In studies using non-affective cognitive tasks, patients overactivated regions involved in self-referential processing (precuneus, posterior cingulate cortex) and underactivated subcortical regions that support goal-directed cognition and motor control (pallidum, ventral anterior thalamus, posterior caudate). The overall pattern suggests that OCD-related brain dysfunction involves increased affective and self-referential processing, enhanced habitual responding and blunted cognitive control.

Arterial Embolism Occurring During Percutaneous Thrombectomy of Dialysis Graft

PURPOSE

To evaluate the incidence, management methods and follow-up results of arterial embolism during percutaneous thrombectomy of hemodialysis grafts.

MATERIALS AND METHODS

After Institutional Review Board approval, the radiologic database of our department for percutaneous thrombectomy procedure in hemodialysis access was retrospectively reviewed. Between 1998 and June 2014, 2975 percutaneous thrombectomy procedures using thromboaspiration technique were performed in 1524 patients with thrombosed hemodialysis grafts. After thrombectomy, angioplasty was performed for significant stenoses. The incidence of arterial embolism was analyzed according to the location/shape of the arteriovenous graft. Percutaneous management methods of arterial embolism and long-term follow-up results by fistulography were also evaluated.

RESULTS

Arterial embolism was documented by angiography in 117 cases (3.9%). Of these, three were symptomatic and subsided after embolectomy. The incidence was significantly correlated with the location/shape of the graft (p = 0.001). Arterial emboli were retrieved using occlusion balloon/Fogarty balloon (n = 58), guiding catheter-assisted aspiration (n = 36), sheath-assisted aspiration (n = 2) and back-bleeding technique (n = 3). Others were observed without intervention (n = 17) or surgically removed (n = 1). Arterial emboli were completely retrieved in 86 cases and partially retrieved in 13 cases. Ulnar artery rupture occurred in one case due to over-inflation of the occlusion balloon. Follow-up fistulography performed in 60 patients among whom 99 percutaneous embolectomies were done revealed arterial stenosis/occlusion in 7 and residual emboli in one patient. In observed patients without intervention, follow-up documented complete resolution of the emboli without arterial stenosis in 9 patients.

CONCLUSION

Radiologically perceivable arterial embolism is uncommon during percutaneous thrombectomy of thrombosed dialysis grafts. The majority of the emboli can be retrieved by percutaneous techniques, but may induce arterial damage in some patients. Clinical observation can be another option for patients without ischemic symptoms.

Amelioration of the Behavioral Phenotype in Genetically Ataxic Mice through Bilateral Intracerebellar Grafting of Fetal Purkinje Cells

We have previously applied neural grafting to “Purkinje cell degeneration” mutant mice (gene symbol pcd, mouse chromosome 13), a model of recessively inherited cerebello-olivary atrophy, to create appropriate interactions between wild-type and mutant cells in elucidating gene effects on the involved neuron populations and to address issues of the structural integration of donor Purkinje cells into the disrupted cerebellar loop. Behaviorally, pcd homozygotes manifest ataxic signs beginning at 3-4 wk of age. The functional effects of cerebellar transplants on motor performance have long remained an open question. The aim of the present study was to determine the recovery of motor responses in pcd mutants in a battery of behavioral tasks after bilateral transplantation of cerebellar cell suspensions (prepared from wild-type mice) into the parenchyma of the deep cerebellar nuclei of the hosts, according to a protocol that emphasizes the reconstruction of the missing inhibitory cortico-nuclear projection. With this approach, the denervated deep nuclei of the host receive a new Purkinje axonal innervation; further, most transplanted Purkinje cells end up occupying cortical localities anyway and display a correct dendritic tree orientation toward the pia. Motor coordination and fatigue resistance were assessed in a rotarod treadmill apparatus, a behavioral paradigm useful in studying various brain abiotrophies and treatments, including developmental perturbations of the cerebellar cytoarchitecture. Locomotor activity was quantified by the number of squares mice crossed as they moved about in an open-field matrix. Grafted pcd mice performed significantly better than sham-operated mutants in both of these tasks. Moreover, graft-recipient mice were able to sustain their abdomen above the floor on their limbs during movement, contrasting to the typical lowered, widened stance of sham-operated pcd mutants. These findings clearly demonstrate that bilateral transplants of fetal Purkinje cells have functional effects on motor performance in the pcd model of hereditary cerebellar ataxia.

Comparison of electric field strength and spatial distribution of electroconvulsive therapy and magnetic seizure therapy in a realistic human head model

BACKGROUND

This study examines the strength and spatial distribution of the electric field induced in the brain by electroconvulsive therapy (ECT) and magnetic seizure therapy (MST).

METHODS

The electric field induced by standard (bilateral, right unilateral, and bifrontal) and experimental (focal electrically administered seizure therapy and frontomedial) ECT electrode configurations as well as a circular MST coil configuration was simulated in an anatomically realistic finite element model of the human head. Maps of the electric field strength relative to an estimated neural activation threshold were used to evaluate the stimulation strength and focality in specific brain regions of interest for these ECT and MST paradigms and various stimulus current amplitudes.

RESULTS

The standard ECT configurations and current amplitude of 800-900mA produced the strongest overall stimulation with median of 1.8-2.9 times neural activation threshold and more than 94% of the brain volume stimulated at suprathreshold level. All standard ECT electrode placements exposed the hippocampi to suprathreshold electric field, although there were differences across modalities with bilateral and right unilateral producing respectively the strongest and weakest hippocampal stimulation. MST stimulation is up to 9 times weaker compared to conventional ECT, resulting in direct activation of only 21% of the brain. Reducing the stimulus current amplitude can make ECT as focal as MST.

CONCLUSIONS

The relative differences in electric field strength may be a contributing factor for the cognitive sparing observed with right unilateral compared to bilateral ECT, and MST compared to right unilateral ECT. These simulations could help understand the mechanisms of seizure therapies and develop interventions with superior risk/benefit ratio.

Effect of the Film-Growth Defects on the Magnetic Microstructure of Epitaxial FePt Thin Film

Effect of the columnar grain boundaries on the perpendicular magnetic domain structure of epitaxial L10 FePt (001) thin film has been studied using electron holography. The analysis of stray fields shows that both the continuous and columnar epitaxial films of L10 FePt (001) consist of perpendicular magnetic domain walls. In the columnar epitaxial film, however, the perpendicular domain walls tend to be confined to columnar grain boundaries, because columnar boundaries act as pinning sites for the domain walls. The domain wall pinning by columnar grain boundaries leads to a significant hysteresis effect in the perpendicular magnetization of L10 FePt epitaxial films.

Microporous Ti implant compact coated with hydroxyapatite produced by electro-discharge-sintering and electrostatic-spray-deposition

A single pulse of 1.5 kJ/0.7 g of atomized spherical Ti powder from 300 μF capacitor was applied to produce the porous-surfaced Ti implant compact by electro-discharge-sintering (EDS). A solid core surrounded by porous layer was self-consolidated by a discharge in the middle of the compact in 122 μsec. Average pore size, porosity, and compressive yield strength of EDS Ti compact were estimated to be about 68.2 μm, 25.5%, and 266.4 MPa, respectively. Coatings with hydroxyapatite (HAp) on the Ti compact were conducted by electrostatic-spray-deposition (ESD) method. As-deposited HAp coating was in the form of porous structure and consisted of HAp particles which were uniformly distributed on the Ti porous structure. By heat-treatment at 700 degrees C, HAp particles were agglomerated each other and melted to form a highly smooth and homogeneous HAp thin film consisted of equiaxed nano-scaled grains. Porous-surfaced Ti implant compacts coated with highly crystalline apatite phase were successfully obtained by using the EDS and ESD techniques.

Calcium and vitamin D intake maintained from preovariectomy independently affect calcium metabolism and bone properties in Sprague Dawley rats

The interaction of habitual Ca and vitamin D intake from preovariectomy to 4 months postovariectomy on bone and Ca metabolism was assessed. Higher Ca intake suppressed net bone turnover, and both nutrients independently benefitted trabecular structure. Habitual intake of adequate Ca and ~50 nmol/L vitamin D status is most beneficial.

INTRODUCTION

Dietary strategies to benefit bone are typically tested prior to or after menopause but not through menopause transition. We investigated the interaction of Ca and vitamin D status on Ca absorption, bone remodeling, Ca kinetics, and bone strength as rats transitioned through estrogen deficiency.

METHODS

Sprague Dawley rats were randomized at 8 weeks to 0.2 or 1.0 % Ca and 50, 100, or 1,000 IU (1.25, 2.5, or 25 μg) vitamin D/kg diet (2 × 3 factorial design) and ovariectomized at 12 weeks. Urinary (45)Ca excretion from deep-labeled bone was used to assess net bone turnover weekly. Ca kinetics was performed between 25 and 28 weeks. Rats were killed at 29 weeks. Femoral and tibiae structure (by μCT), dynamic histomorphometry, and bone Ca content were assessed.

RESULTS

Mean 25(OH)D for rats on the 50, 100, 1,000 IU vitamin D/kg diet were 32, 54, and 175 nmol/L, respectively. Higher Ca intake ameliorated net bone turnover, reduced fractional Ca absorption and bone resorption, and increased net Ca absorption. Tibial and femoral trabecular structures were enhanced independently by higher Ca and vitamin D intake. Tibial bone width and fracture resistance were enhanced by higher vitamin D intake. Dynamic histomorphometry in the tibia was not affected by either nutrient. A Ca × vitamin D interaction existed in femur length, tibial Ca content, and mass of the soft tissue/extracellular fluid compartment.

CONCLUSIONS

Adequate Ca intake and serum 25(OH)D level of 50 nmol/L provided the most benefit for bone health, mostly through independent effects of Ca and vitamin D.

Remodeling of rabbit abdominal aorta and Cx43 gap junctions after stent placement: effect of balloon injury plus cholesterol-enriched diet

AIM

To examine the effect of stenting and cholesterol-enriched diet (CED) on vascular remodeling, including the expression of connexin43 (Cx43) gap junctions in smooth muscle cells (SMC).

METHODS

Rabbits abdominal aortae were either implanted stent made of 316 stainless steel (group 1) or denuded followed by stent placement 28 days later (groups 2 and 3). Animals were given normal chow except those of group 3, which were fed CED after the denudation. Eight weeks later, the development of neointima and the expression of connexin43 (Cx43) were examined. In parallel, human aortic SMC were grown on 316 stainless steel or treated with C-reactive protein (CRP) followed by analysis of Cx43.

RESULTS

The results showed that, serum CRP levels became transiently elevated after denudation and stent implantation. For the stented aortic segments, the dimensions of neointima were group 3 > group 2 > group 1 (P<0.05). In groups 1 and 2, Cx43 gap junctions are less in amount in neointima of the stented segment, compared to the unstented upstream neointima or medial layer (all P<0.01). In culture experiments, Cx43 in SMC grown on stent material was up-regulated in growth medium but down-regulated in differentiation medium, and CRP did not affect Cx43 expression.

CONCLUSION

Vascular remodeling post stent implantation varied according to the presence of balloon injury, CED, or both. Cx43 expression in SMC is altered after exposure to stent and the regulation depended on the milieu.

Simple isotopic method using oral stable or radioactive tracers for estimating fractional calcium absorption in adult women

We extended a simple oral method for estimating fractional calcium absorption determined by double isotopic methods using radioactive or stable isotope across wide age of adult women. Fractional calcium absorption can be estimated by using either a radioactive or stable oral isotope across the entire age spectrum of adult women.

INTRODUCTION

A method for estimating fractional calcium absorption using a single serum collection following a single oral radioactive isotopic tracer has been validated against a classical double isotopic tracer ratio method in adults. Our goal was to extend this simplified method to include use of stable isotopes and a broad age range.

METHODS

We used our database of 56 observations from 26 white adult women aged 19-67 years receiving either radioactive or stable isotopes. Reference values for fractional calcium absorption were determined from 24-h double isotopic ratios in serum and urine and from full kinetic modeling.

RESULTS

Equations for estimating fractional calcium absorption were developed from isotopic enrichment in serum and urine from an oral tracer and measures of body size using the multiple linear regression analysis. Equations using a 4- to 6-h sample following an oral dose of either a stable or radioactive isotope corrected for body size were highly correlated with the reference values for fractional calcium absorption across different aged populations (r > 0.8, p < 0.001).

CONCLUSION

Fractional calcium absorption can be estimated by a single oral tracer method using either radioactive or stable calcium isotopes across the entire age spectrum in healthy white adult women.

A pilot study of brain activation in children with trichotillomania during a visual-tactile symptom provocation task: a functional magnetic resonance imaging study

OBJECTIVES

In order to reveal the etiology and pathophysiology of trichotillomania (TTM), it is necessary to investigate which brain regions are involved in TTM, but limited knowledge exists regarding the neurobiology of TTM and the available functional neuroimaging studies of TTM are little. The purpose of the present study was to investigate the specific brain regions involved in the pathophysiology of TTM with symptom provocation task using functional magnetic resonance imaging (fMRI) for children and adolescents with TTM.

METHODS

Pediatric subjects who met the DSM-IV TR criteria for TTM (n=9) and age-, sex-, handedness-, IQ matched healthy controls (HC) (n=10), ages 9 to 17 years, were recruited for two fMRI experiments; symptom provocation of Visual Only (VO) and Visual and Tactile (VT). They were scanned while viewing two alternating blocks of symptom provocation (S) and neutral (N) movies.

RESULTS

Random effects between-group analysis revealed significant activation in left temporal cortex(including middle and superior temporal gyrus), dorsal posterior cingulate gyrus, and putamen for the contrast S>N in TTM subjects versus HC subjects during the VO session. And TTM subjects demonstrated higher activity in the precuneus and dorsal posterior cingulate gyrus to the contrast S>N during the VT session.

CONCLUSIONS

This study provided an objective whole-brain-based analysis that directed researchers to areas that were abnormal in TTM. Using the symptom provocation tasks, we found significant differences in regional brain function between pediatric TTM and HC subjects. However, in the face of modest statistical power, our preliminary findings in TTM need to be replicated in a larger sample. As the functional neuroanatomic circuits involved in TTM remain largely unexplored, future functional neuroimaging studies using other various paradigms may help investigate the neuroanatomic abnormalities of TTM.

3-D diffusion tensor MRI anisotropy content-adaptive finite element head model generation for bioelectromagnetic imaging

Realistic finite element (FE) head models have been successfully applied to bioelectromagnetic problems due to a realistic representation of arbitrary head geometry with inclusion of anisotropic material properties. In this paper, we propose a new automatic FE mesh generation scheme to generate a diffusion tensor MRI (DT-MRI) white matter anisotropy content-adaptive FE head model. We term this kind of mesh as wMesh. With this meshing technique, the anisotropic electrical conductivities derived from DT-MRIs can be best incorporated into the model. The influence of the white matter anisotropy on the EEG forward solutions has been studied via our wMesh head models. The scalp potentials computed from the anisotropic wMesh models against those of the isotropic models have been compared. The results describe that there are substantial changes in the scalp electrical potentials between the isotropic and anisotropic models, indicating that the inclusion of the white matter anisotropy is critical for accurate computation of E/MEG forward and inverse solutions. This fully automatic anisotropy-adaptive wMesh meshing scheme could be useful for modeling of individual-specific FE head models with better incorporation of the white matter anisotropic property towards bioelectromagnetic imaging.

A new Kondo antiferromagnet Ce(Ni(0.25)In(1.75))

We find that Ce(Ni(0.25)In(1.75)) crystallizes in the hexagonal AlB(2)-type structure with lattice parameters a = 0.4850(5) nm and c = 0.3908(5) nm. Magnetic susceptibility, electrical resistivity and low-temperature specific heat data reveal that the bulk phase transition at 3.7 ± 0.2 K in Ce(Ni(0.25)In(1.75)) is to an antiferromagnetic state. The magnetic contribution to the resistivity ρ(mag) of Ce(Ni(0.25)In(1.75)) increases as ln(T) when temperature is lowered from room temperature and reaches a plateau at 9 K, followed by a rapid decrease around 4 K. These results associated with a reduction of the Ce magnetic moment and of the magnetic entropy at T(N) suggest that Ce(Ni(0.25)In(1.75)) could be a Kondo antiferromagnet. The Kondo temperature is estimated to be of order 6 K.

Extraordinary transmittance in three dimensional crater, pyramid, and hole-array structures prepared through reversal imprinting of metal films

We used a reversal imprinting-in-metal (RIM) process to fabricate various three-dimensional (3D) metal structures under low pressure. Molds featuring different shapes were used to pattern various subwavelength metal structures, including pyramidal, hole-array, and crater-like structures. Refractive index matching and cavity effects both enhanced the degree of transmission of these structured metal films. The crater-like structure appears to be a promising material because of the unique properties imparted by the elongated and gradually tapering spacing of its cavities. From both near-field simulations and experimentally obtained optical spectra, we found that the cavity effect in the crater-like structure led to significantly enhanced transmission of the optical intensity. Thus, this RIM process allows the ready fabrication of various two- and three-dimensional metallic structures for use in surface plasmon-based devices.

The Severe Cognitive Impairment Rating Scale--an instrument for the assessment of cognition in moderate to severe dementia patients

BACKGROUND/AIMS

This study aimed to develop a brief, reliable and valid test for cognitive function of severely demented patients.

METHODS

We constructed the Severe Cognitive Impairment Rating Scale, which consisted of 11 items covering memory, language, visuospatial function, frontal function and orientation, and investigated its reliability and validity on 267 subjects [normal: 65, very mild Alzheimer's disease (AD): 42, mild AD: 58, moderate AD: 36, severe AD: 44, profound AD: 22].

RESULTS

The internal consistency obtained by Cronbach's coefficient alpha was 0.93. The interrater reliability and test-retest reliability in the moderately to severely impaired subjects with an MMSE score of <or=14 was 0.99 (p < 0.001) and 0.90 (p < 0.001), respectively. It showed significant correlation with Severe MMSE (r = 0.96, p < 0.01), MMSE (r = 0.86, p < 0.01) and Clinical Dementia Rating (r = -0.83, p < 0.01). It was robust to both the floor effect in the severe/profound stage of AD and the ceiling effect in the mild/moderate stage of AD. Exploratory factor analysis yielded 2 factors (automatic informational processing and controlled informational processing) accounting for 73.5% of the total variance.

CONCLUSIONS

The Severe Cognitive Impairment Rating Scale is a valid and reliable test for evaluating the cognitive function of advanced AD patients.

Continuous and discrete stable processes

The one-sided Lévy-stable probability densities and the discrete-stable distributions form a doubly stochastic Poisson transform pair. This relationship facilitates the formulation of a class of continuous-stable stochastic processes.

Extraction and localization of alpha activity of the brain in EEG and fMRI using constrained ICA

In order to extract only the alpha activity related EEG signals of the brain, we have applied constrained Independent Component Analysis (cICA), a new extension of ICA in which some a priori knowledge of alpha activity is utilized to extract desired components. Its performance has been compared to that of conventional band-pass filtering via the scalp power maps of alpha activity. The preliminary results show that cICA-extracted alpha signals produce the alpha power maps which spatially match the activated regions of the brain mapped using fMRI more closely than those from the band-pass filtered alpha EEG signals. The use of cICA might provide a more effective means of extracting EEG alpha activity of the brain.

Methods and evaluations of MRI content-adaptive finite element mesh generation for bioelectromagnetic problems

In studying bioelectromagnetic problems, finite element analysis (FEA) offers several advantages over conventional methods such as the boundary element method. It allows truly volumetric analysis and incorporation of material properties such as anisotropic conductivity. For FEA, mesh generation is the first critical requirement and there exist many different approaches. However, conventional approaches offered by commercial packages and various algorithms do not generate content-adaptive meshes (cMeshes), resulting in numerous nodes and elements in modelling the conducting domain, and thereby increasing computational load and demand. In this work, we present efficient content-adaptive mesh generation schemes for complex biological volumes of MR images. The presented methodology is fully automatic and generates FE meshes that are adaptive to the geometrical contents of MR images, allowing optimal representation of conducting domain for FEA. We have also evaluated the effect of cMeshes on FEA in three dimensions by comparing the forward solutions from various cMesh head models to the solutions from the reference FE head model in which fine and equidistant FEs constitute the model. The results show that there is a significant gain in computation time with minor loss in numerical accuracy. We believe that cMeshes should be useful in the FEA of bioelectromagnetic problems.

The shape control of ZnO based nanostructures

Tetrapod-shape ZnO nanostructures are formed on Si substrates by vapor phase transportation method. The effects of two important growth parameters, growth temperature and VI/II ratio, are investigated. The growth temperature is varied in the range from 600 degrees C to 900 degrees C to control the vapor pressure of group II-element and the formation process of nanostructures. VI/II ratio was changed by adjusting the flux of carrier gas which affects indirectly the supplying rate of group VI-element. From the scanning electron microscopy (SEM), systematic variation of shape including cluster, rod, wire and tetrapod was observed. ZnO tetrapods, formed at 800 degrees C under the carrier gas flux of 0.5 cc/mm2 min, show considerably uniform shape with 100 nm thick and 1-1.5 microm long legs. Also stoichiometric composition (O/Zn - 1) was observed without any second phase structures. While, the decrease of growth temperature and the increase of carrier gas flux, results in the irregular shaped nanostructures with non-stoichiometric composition. The excellent luminescence properties, strong excitonic UV emission at 3.25 eV without deep level emission, indicate that the high crystalline quality tetrapod structures can be formed at the optimized growth conditions.

REVERSIBLE ACTIVATION FOR GERMINATION AND SUBSEQUENT CHANGES IN BACTERIAL SPORES

Lee, W. H. (University of Illinois, Urbana) and Z. John Ordal. Reversible activation for germination and subsequent changes in bacterial spores. J. Bacteriol. 85:207-217. 1963.-It was possible to isolate refractile spores of Bacillus megaterium, from a calcium dipicolinate germination solution, that were activated and would germinate spontaneously in distilled water. Some of the characteristics of the initial phases of bacterial spore germination were determined by studying these unstable activated spores. Activated spores of B. megaterium were resistant to stains and possessed a heat resistance intermediate between that of dormant and of germinated spores. The spontaneous germination of activated spores was inhibited by copper, iron, silver, or mercury salts, saturated o-phenanthroline, or solutions having a low pH value, but not by many common inhibitors. These inhibitions could be partially or completely reversed by the addition of sodium dipicolinate. The activated spores could be deactivated and made similar to dormant spores by treatment with acid. Analyses of the exudates from the variously treated spore suspensions revealed that whatever inhibited the germination of activated spores also inhibited the release of spore material. The composition of the germination exudates was different than that of extracts of dormant spores. Although heavy suspensions of activated spores gradually became swollen and dark when suspended in solutions of o-phenanthroline or at pH 4, the materials released resembled those found in extracts of dormant spores rather than those of normal germination exudates.

Limbs Anthropometry of Singleton Chinese Newborns of 28–42 Weeks’ Gestation

Abnormalities of limbs are important features of some syndromes recognizable at birth. The purpose of this study was to establish normal standards of limbs including arm length, arm circumference, upper arm length, lower arm length, leg length, thigh circumference, upper leg length, and lower leg length. 10,226 infants (5,422 males, 4,804 females) with gestation 28-42 weeks from 12 hospitals were included. The LMS method using maximum penalized likelihood was used to perform model fitting of the anthropometric centiles for these parameters. This study provided the first set of references for the limbs of the infants by gestation and gender. Racial differences were found when comparing with other populations. The parameters are useful for evaluation of morphologic disorders involving the limbs.

Trunk anthropometry of Hong Kong Chinese infants

BACKGROUND

Disturbed growth of the trunk may result in abnormal sternocostal relationship and a variety of pectus deformities.

AIMS

The purposes of this study were to establish norms of trunk anthropometry for dysmorphology identification in the newborns and to evaluate chest circumference as a predictor for low birth weight for outborn infants where weighing scales were unavailable.

STUDY DESIGN AND SUBJECTS

A total of 10,339 Chinese infants (5478 males, 4861 females) with gestation 24-42 weeks from 12 hospitals were included. The anthropometric measurements analyzed included chest circumference, inter-nipple distance, sternal length and abdominal circumference.

OUTCOME MEASURES

The LMS method using maximum penalized likelihood was used to perform model fitting of the anthropometric centiles for these physical parameters.

RESULTS

References tables of the four physical parameters for newborns were constructed. Chest circumference showed the highest correlation with birth weight (male: r = 0.866, female: r = 0.883). The cut-off points for chest circumference of 295 (male) and 299 mm (female) were the best predictor for low birth weight. There were also racial differences in these parameters. When compared with French infants, Chinese newborns had smaller chest circumference.

CONCLUSION

These physical parameters provide useful references and aid dysmorphology diagnosis in newborns of ethnic Chinese origin.

Molecular models of the procoagulant factor VIIIa-factor IXa complex

BACKGROUND

Formation of the intrinsic tenase complex is an essential event in the procoagulant reactions that lead to clot formation. The tenase complex is formed when the activated serine protease, Factor IXa (FIXa), and its cofactor Factor VIIIa (FVIIIa) assemble on a phospholipid surface to proteolytically convert the zymogen Factor X (FX) into its active form FXa. The physiological relevance of the tenase complex is evident in hemophilia A or B patients who present with bleeding disorders.

OBJECTIVES

The purpose of this study was to establish three-dimensional (3D) models of the FVIIIa-FIXa complex.

METHODS

First, we built two new theoretical models of FVIIIa via homology modeling, inter-domain docking and loop simulation algorithms as well as a model for FIXa. This was followed by pseudo-Brownian protein-protein docking in internal coordinates with the ICM (Internal Coordinates Mechanics) program between the two FVIIIa and the FIXa structures.

RESULTS

Ten representative models of this complex are presented based on agreements with known experimental data and according to structural criteria.

CONCLUSIONS

These novel 3D models will help guide future site directed mutagenesis aimed at improving the functionality of FVIIIa and/or FIXa and will contribute to a better understanding of the role of this macromolecular complex in the blood coagulation cascade.

Normative Data of Penile Length for Term Chinese Newborns

Careful examination and assessment of penile length in the newborn is important because micropenis is associated with hypothalamic disorders. This prospective cross-sectional study was designed to establish the norm of penile length for term Hong Kong Chinese newborns. 4,628 full-term healthy male newborns were enrolled in the study. Penile length was measured from pubic ramus to the tip of the glans penis by placing the end of a straight edge ruler against the pubic ramus. A gestation-associated graph of 3rd, 10th, 25th, 50th, 75th, 90th and 97th centiles for the penile length was created. The penile length was significantly correlated with gestational age, birth weight and body length. When compared with published data for other populations, Hong Kong newborns have significantly shorter penile length. The norm of the penile length is useful in diagnostic and therapeutics for the ethnic Chinese male newborns.

Fetal growth velocities in Hong Kong Chinese infants

Few studies have investigated the velocities of fetal growth. The aim of the present study was to determine the pattern of 'fetal' growth velocities in a Chinese population. The gestation-specific measurements of the body weight, body length and head circumference in a representative sample of 5,045 male and 4,484 female newborns delivered between 26 and 42 weeks of gestation at 12 hospitals in Hong Kong were obtained. Peak growth velocity occurred before 30 weeks of gestation for head circumference, at week 30 for length and at week 30 for weight. When compared with data obtained from a French population, a significant difference in the growth velocity for body weight was observed below 32 weeks between French and Chinese infants, suggesting an ethnic difference in fetal growth of this parameter.

Role of NADP+-dependent isocitrate dehydrogenase (NADP+-ICDH) on cellular defence against oxidative injury by gamma-rays

PURPOSE

To investigate the regulation of NADPH-producing isocitrate dehydrogenase (ICDH) in cytosol (IDPc) and mitochondria (IDPm) upon gamma-ray irradiation, and the roles of IDPc and IDPm in the protection against cellular damage induced by gamma-ray irradiation.

MATERIALS AND METHODS

Changes of IDPc and IDPm proteins upon gamma-ray irradiation to NIH3T3 cells were analysed by immunoblotting. To increase or decrease the expression of IDPc or IDPm, NIH3T3 cells were stably transfected with mouse IDPc or IDPm cDNA in either the sense or the antisense direction. The transfected cells with either increased or decreased IDPc or IDPm were exposed to gamma-rays, and the levels of reactive oxygen species generation, protein oxidation and lipid peroxidation were measured.

RESULTS

Both IDPc and IDPm activities were induced by gamma-ray in NIH3T3 cells. Cells with decreased expression of IDPc or IDPm had elevated reactive oxygen species generation, lipid peroxidation and protein oxidation. Conversely, overproduction of IDPc or IDPm protein partially protected the cells from oxidative damage induced by gamma-ray irradiation.

CONCLUSIONS

The protective role of IDPc and IDPm against gamma-ray-induced cellular damage can be attributed to elevated NADPH, reducing equivalents needed for recycling reduced glutathione in the cytosol and mitochondria. Thus, a primary biological function of the ICDHs may be production of NADPH, which is a prerequisite for some cellular defence systems against oxidative damage.

Analysis of genes responding to ultraviolet B irradiation of HaCaT keratinocytes using a cDNA microarray

BACKGROUND

Ultraviolet (UV) B irradiation causes many important biological changes in skin, which lead to pathophysiological alterations of the homeostatic environment.

OBJECTIVES

To gain more insight into the molecular events provoked by UVB irradiation, we performed cDNA microarray analysis.

METHODS

Immortalized HaCaT keratinocytes were irradiated with a high cytotoxic dose of UVB (50 mJ cm(-2)), and total RNA was isolated. Fluorescently labelled probes were prepared by reverse transcription and were hybridized with cDNA microarray slides made using 840 cDNA clones.

RESULTS

Time-course cDNA microarray analysis revealed the global gene expression profile after UVB exposure. Of 840 genes tested, 192 genes showed changes in their expression levels at one or more of four time points. The genes were clustered into four groups according to their expression patterns in a self-organizing maps analysis. Classification of these genes into nine functional categories revealed that UVB irradiation affected several biological processes. The genes that were first upregulated and then returned to normal levels included several genes related to the inhibition of cell growth and the proteasome pathway. Conversely, the expressions of many genes involved in the cytoskeleton, signal transduction, metabolism and transcription were first downregulated or unchanged and then upregulated later, reflecting the recovery of UVB-damaged cellular activities.

CONCLUSIONS

These results demonstrate the complexity of the transcriptional profile of the UVB response, and provide a basis for the global characterization of UV-regulated gene expression.

Immunomodulating Effects of CKBM on the Cytokine Production in Peripheral Blood Mononuclear Cells (PBMCs) from Healthy Volunteers

The current study investigated the immunomodulating effect of CKBM on cytokine induction in peripheral blood mononuclear cells (PBMCs) isolated from 20 healthy volunteers. Cytometric Bead Analysis (CBA) was used to study IL-2, IL-4, IL-6, IL-10, TNF-alpha and IFN-gamma. TNF-alpha and IL-6 were significantly increased in a CKBM dose- and time-dependent manner. Flow cytometry analysis showed an increased intracellular staining of IL-6 but not of TNF-alpha in CKBM treated PBMCs. In addition, MTT cell cytotoxicity assay showed that CKBM concentrations below 5% did not significantly affect the metabolic activities of PBMCs. The current study indicated that CKBM may modulate the immune response by inducing the secretions of TNF-alpha and IL-6, which are cytokine mediators of innate immunity and inflammation preparing or "priming" the body to combat diseases.

Heterogeneity detector: finding heterogeneous positions in Phred/Phrap assemblies

A modification to Phred and program to detect heterogeneous positions, which is particularly useful in the identification of mutations and other abnormalities in Phred/Phrap genome assemblies.

AVAILABILITY

The package is made available at http://glscompute.gis.a-star.edu.sg/~charlie/DHetero.html

A rare cause of intestinal perforation in an extreme low birth weight infant--gastrointestinal mucormycosis: a case report

We report an extreme low birth weight infant with gastrointestinal mucormycosis (GM) mimicking necrotizing enterocolitis on day 15 of age. Emergency laparotomy confirmed ileal perforations. Subsequently, tissue histology confirmed GM. This is the most premature infant who survived after GM and is the third reported neonatal survivor in English literature.

Maternal diclofenac sodium ingestion and severe neonatal pulmonary hypertension

We describe a case of severe pulmonary hypertension and transient right-sided hypertrophic cardiomyopathy in a neonate, caused by premature closure of ductus arteriosus after short-term maternal use of diclofenac sodium (Voltaren). In view of this associated complication, diclofenac sodium should be avoided during pregnancy. In addition, maternal diclofenac sodium ingestion should be suspected if a newborn develops severe pulmonary hypertension and/or right-sided hypertrophic cardiomyoptathy with closed ductus arteriosus.

Ammonium nitrogen removal from slurry-type swine wastewater by pretreatment using struvite crystallization for nitrogen control of anaerobic digestion

Precipitation of ammonium together with phosphate and magnesium is a possible alternative for lowering the nitrogen content of wastewater. In this study we examine the removal of ammonium nitrogen and phosphorus from slurry-type swine wastewater containing high concentrations of nutrients by the addition of phosphoric acid along with either calcium oxide or magnesium oxide, which leads to the crystallization of insoluble salts such as hydroxyapatite and struvite. The struvite crystallization method showed a high capacity for the removal of nitrogen when magnesium oxide and phosphoric acid were used as the magnesium and phosphate sources, respectively. When it was applied to swine wastewater containing a high concentration of nitrogen, the injection molar ratio of Mg2+:NH4+:PO4(3-) that gave maximum ammonium nitrogen removal was 3.0:1.0:1.5.

Updated gestational age specific birth weight, crown-heel length, and head circumference of Chinese newborns

OBJECTIVE

To construct gestation specific standards of birth weight, crown-heel length, and head circumference of Chinese infants.

DESIGN

A prospective cross sectional population study.

METHODS

The birth weight, crown-heel length, and head circumference were prospectively measured using standard equipment in newborns delivered at 24-42 weeks gestation in the maternity units of 10 public hospitals and two private hospitals in Hong Kong. The findings were used to construct gestation specific standards of these variables. The LMS method using maximum penalised likelihood was used to perform model fitting. The results were compared with those obtained from a cohort of infants born in the same locality between 1982 and 1986.

RESULTS

From October 1998 to September 2000, a total of 10 032 infants were measured, representing 9.6% of the total deliveries in Hong Kong during that period. An extra 307 infants with gestation < or = 35 weeks were recruited from October 2000 to June 2001. Each of the three variables showed a normal distribution at each gestational week. Gestation specific reference standards for each variable were constructed for male and female infants separately. Comparison with the 1982-1986 cohort showed a significant secular trend to increased birth weight. The trend was small, but significant, for crown-heel length and head circumference.

CONCLUSION

These growth standards will provide useful references for the care of newborns of ethnic Chinese origin. These standards, especially that for birth weight, should be updated regularly.

A double-blind, randomised- placebo, controlled, parallel group, multicentre, flexible-dose escalation study to assess the efficacy and safety of sildenafil administered as required to male outpatients with erectile dysfunction in Korea

The efficacy and safety of sildenafil was evaluated in a randomiSed, double-blind, placebo-controlled, flexible-dose study in Korean men aged 28-78 y with erectile dysfunction (ED) of broad-spectrum aetiology and more than 6 months duration. A total of 133 patients were randomised at six centres in Korea to receive either sildenafil (50 mg initially, increased if necessary to l00 mg or decreased to 25 mg depending on efficacy and tolerance) (n=66) or matching placebo (n=67) taken on an 'as needed' basis l h prior to anticipated sexual activity for a period of 8 weeks. At the end of this time, the primary efficacy variables relating to the achievement and maintenance of erections sufficient for sexual intercourse, and the secondary efficacy variables, which included: (1) the five separate domains of sexual functioning of the International Index of Erectile Function (IIEF) scale, (2) the percentage of successful intercourse attempts, and (3) a global assessment of erections, were all statistically significantly improved by sildenafil in comparison with placebo (P&<0.0001). Treatment-related adverse events occurred in 56.1% of patients receiving sildenafil and 20.9% receiving placebo. The most common adverse events with sildenafil were vasodilatation (flushing), headache and abnormalities in colour vision (31.8, 22.7 and 6.1% of patients, respectively), and most were mild in nature. The efficacy and safety of sildenafil in this population of Korean men appears similar to that reported in other studies in western populations.

Polyhydroxyalkanoate (PHA) production from waste

PHA (polyhydroxyalkanoate) production was attempted with SBRs from food waste. Seed microbes were collected from a sewage treatment plant with a biological nutrient removal process, and acclimated with synthetic substrate prior to the application of the fermented food waste. Laboratory SBRs were used to produce PHA with limited oxygen and nutrients. The maximum content of 51% PHA was obtained with an anaerobic/aerobic cycle with P limitation, and the yield was estimated to be about 0.05 gPHA(produced)/gCOD(applied) or 25 kg PHA/dry ton of food waste, assuming more than 40% of the PHA contents were recoverable. PHB/PHA ratios were 0.74 to 0.77 due to the higher acetate concentrations. Economical analysis seemed to suggest the PHA produced from the food waste could be an alternative material to produce the biodegradable plastic to be used for the collection bags for solid waste.