K(L) - K(S) mass difference from lattice QCD

We report on the first complete calculation of the K_{L}-K_{S} mass difference, ΔM_{K}, using lattice QCD. The calculation is performed on a 2+1 flavor, domain wall fermion ensemble with a 330 MeV pion mass and a 575 MeV kaon mass. We use a quenched charm quark with a 949 MeV mass to implement Glashow-Iliopoulos-Maiani cancellation. For these heavier-than-physical particle masses, we obtain ΔM_{K}=3.19(41)(96)×10^{-12}  MeV, quite similar to the experimental value. Here the first error is statistical, and the second is an estimate of the systematic discretization error. An interesting aspect of this calculation is the importance of the disconnected diagrams, a dramatic failure of the Okubo-Zweig-Iizuka rule.

Occipital somites guide motor axons of the accessory nerve in the avian embryo

The accessory nerve (nervus accessorius) displays a unique organization in that its axons ascend along the rostrocaudal axis after exiting the cervical spinal cord and medulla oblongata and thereafter project ventrally into the periphery at the first somite level. Little is known about how this organization is achieved. We have investigated the role of somites in the guidance of motor axons of the accessory nerve using heterotopic transplantations of somites in avian embryos. The formation of not only accessory nerve but also the vagal nerve was affected, when a more caudal occipital somite (somites 2-4) was grafted to the position of the first occipital somite. Our study reveals that only the first occipital somite permits the development of ventral projection of accessory axons, a process that is inhibited by more caudal occipital somites.

A simple QSPR model for the prediction of the adsorbability of organic compounds onto activated carbon cloth

A quantitative structure-property relationship (QSPR) model was proposed between the molecular descriptors representing the molecular structure and the Freundlich adsorbability parameter (K) for a set of 55 organic compounds onto activated carbon cloth. The best linear model was composed of three descriptors, which were selected by stepwise multiple linear regression (MLR) analysis. The statistical parameters provided by the linear model were r² = 0.7744, r²(adj) = 0.7551, s = 0.169 for the training set; and r² = 0.6725, r²(adj) = 0.6316, s = 0.196 for the external test set, respectively. The stability and predictive power of the proposed model were further verified using Y-randomization tests, five-fold cross-validation and leave-many-out cross-validation. The model may give some insight into the main structural features that affect the adsorption of the investigated compounds onto activated carbon cloth.

Changes of Reflex, Non-reflex and Torque Generation Properties of Spastic Ankle Plantar Flexors Induced by Intelligent Stretching

Spasticity, contracture, and muscle weakness are major sources of disability in stroke. Changes of torque-generating capacity as well as reflex and non-reflex properties of ankle plantar flexors induced by strenuous stretching in chronic hemiplegia were investigated. Twelve subjects with a unilateral stroke and 10 healthy controls underwent 30 minutes of strenuous intelligent stretching treatment. Reflex and non-reflex components of spastic hypertonia and force-generating capacity of ankle plantar flexors were investigated. Dorsiflexion (DF) range of motion (ROM) was increased (p=0.002) and passive stiffness and passive resistant torque of the spastic muscles were decreased (p=0.004 and 0.007, respectively), while reflex hyper-excitability diminished slightly but with no statistical significance. The maximal voluntary contraction (MVC) torque of the spastic ankle plantar flexors was increased after the forceful stretching treatment (p=0.041). In contrast, the stretching treatment of the healthy plantar flexors did not change any of the variables measured before and after stretching. The stroke subjects who gained more DF ROM or larger decrement of stiffness achieved greater increment of the peak torque generation after the stretching (r=0.597 with p=0.040 and r=-0.746 with p=0.005, respectively). These results suggest that the strenuous dynamic stretching could improve the force-generating capacity of spastic muscles as well as reduce the passive stiffness and increase ROM.

Cu fractions, mobility and bioavailability in soil-wheat system after Cu-enriched livestock manure applications

Fertilization of crops with livestock manure (LM) is a common waste disposal option, but repeated application of LM containing high concentrations of heavy metals such as Cu could lead to crop toxicity and environmental risk. To examine the Cu availability and uptake by wheat in a Mollisol affected by Cu-enriched LM, pot experiments were conducted. LM (376 mg kg⁻¹ Cu originally) was spiked with different concentrations of Cu (0, 100, 200, 400, 600 and 800 mg kg⁻¹ soil, added as CuSO⁴) to simulate soil Cu contamination by LM application. The results indicated that Cu was predominately distributed in organic bound fraction, while the most drastic increase was found in reducible fraction. Acid-extractable fraction played a more important role than other fractions in controlling the mobility and bioavailability of Cu. DTPA-extractable Cu may overestimate the Cu bioavailability since DTPA solution could extract soluble and part of stable forms. The application of LM at 1% level significantly decline the Cu mobility, but that at 3% level exhibited the opposite effect. Although the quantities of Cu in wheat was very low compared with the accumulation in soil, Cu concentrations in roots increased evidently from 12 to 533 mg kg⁻¹ and that in aerial parts were in a narrow range from 12.1 to 32.7 mg kg⁻¹, indicating the more sensitivity of roots to the Cu toxicity. The Cu concentrations in grains after 3% manure application did not approach the threshold for Cu toxicity (< 20mg kg⁻¹) even at higher Cu addition rates.

The relationship between changes in self-rated quality of life after cochlear implantation and changes in individual complaints

OBJECTIVES

To evaluate the changes in self-rated quality of life (QoL) obtained following cochlear implantation in relation to changes in the individual's complaints.

DESIGN

We have used repeated responses over a period of at least 4 years following implantation so as to examine within-subject relationships.

PARTICIPANTS

Twenty-four consecutive post-lingually deafened patients who had been fitted with cochlear implants between 1991 and December 2000 at the University Hospital of Wales were investigated.

MAIN OUTCOME MEASURES

The open-ended problems questionnaire was used to assess what hearing impaired people themselves considered to be the main problems arising from their hearing loss. The participants were asked to rate the severity of each one of these problems as well as QoL on '0' to '100' visual analogue scales. Both the individual problem ratings and the ratings of QoL were re-administered to the subjects at each follow-up session.

RESULTS

Changes in the rated QoL of all patients were significantly associated with changes in specific complaints, for example, the ability to communicate, feeling of isolation, telephone use, self-confidence, enjoyment of music and watching the TV. Multiple stepwise regression analysis showed that, after implantation, improvements in communication abilities, reduced psychological problems and improvements in abilities of daily life were the key determinants of QoL improvement for individual cochlear implant patients. These key predictors reached a plateau at about 1.5-3 years after cochlear implantation.

CONCLUSIONS

The relationships between changes in specific complaints and the QoL in individual implantees were highlighted. We suggest that cochlear implant outcome measures should continue for at least 3 years after implantation.

Differentiation of mouse nuclear transfer embryonic stem cells into functional pancreatic beta cells

AIMS/HYPOTHESIS

Therapeutic cloning has been reported to have potential in the treatment of several degenerative diseases. However, it has yet to be determined whether mouse nuclear transfer-embryonic stem cells (NT-ESCs) can be differentiated into pancreatic beta cells and used to reverse diabetes in an animal model.

METHODS

We first used the somatic nuclear transfer technique to generate mouse NT-ESCs and then developed a chemically defined stepwise protocol to direct the NT-ESCs into functional pancreatic beta cells. We examined the gene expression pattern of the differentiated NT-ESCs and transplanted the NT-ESC-derived insulin-producing cells into recipient diabetic mice.

RESULTS

Four mouse NT-ESC lines were first established using an improved nuclear transfer technique and insulin-producing cells were efficiently generated from NT-ESCs by mimicking pancreatic in vivo development. Most of the insulin-producing cells that we generated co-produced pancreatic and duodenal homeobox 1, but not glucagon at the final stage of this differentiation method, which differed from the insulin and glucagon co-production reported by other groups. The differentiated NT-ESCs were able to release insulin in response to glucose stimuli and normalise the blood glucose level of diabetic mice for at least 2 months.

CONCLUSIONS/INTERPRETATION

These results demonstrate the potential of therapeutic cloning for cell therapy of type 1 diabetes in a mouse model.

Heterogeneous decomposition of indoor ammonia in a photoreactor with TiO2-finished cotton fabrics

Addition of urea-based antifreeze admixtures during cement mixing can make it possible to concrete cement in construction of buildings in cold weather. This, however has led to increasing indoor air pollution due to continuous transformation and emission from urea to gaseous ammonia in indoor concrete walls. In order to control ammonia from indoor concrete walls, aqueous dispersion of nano-titanium dioxide (TiO2) was prepared and mixed with silicone additive to establish a treating bath. Cotton fabrics were finished with this treating bath by using pad-dry-cure process and then characterized by X-Ray Diffractometer, Infrared Fourier Transform Spectrometer and Scanning Electron Microscope. The gaseous ammonia was derived from an environmental condition simulated chamber. The heterogeneous decomposition of gaseous ammonia by UV/TiO2 process in an annular photoreactor fixed with the TiO2-coated cotton fabric was studied under various dosages of aqueous nano-TiO2 dispersion, initial ammonia concentration, relative humidity and gas flow rate. A design equation of surface catalytic kinetics was developed for describing the decomposition of ammonia in air streams by UV/TiO2 process at given operating conditions. Experimental results indicated that increasing dosage of aqueous nano-TiO2 dispersion improved the ammonia decomposition of cotton fabric, which was prepared. At a constant temperature of 25 degrees C, ammonia in the air stream was effective removed by decreasing initial ammonia concentration and gas flow rate. For moisture in the range of 15-65%, when the relatively humidity level was increased to 45%, the decomposition of ammonia was remarkably enhanced, and the decomposition of ammonia could be inhibited by excessive moisture.

Emission of ammonia from indoor concrete wall and assessment of human exposure

Addition of urea-based antifreeze admixtures during cement mixing can make it possible to produce concrete cement in construction of buildings in cold weather; this, however, has led to increasing indoor air pollution due to continuous transformation and emission from urea to gaseous ammonia in indoor concrete wall. It is believed that ammonia is harmful to human body and exposure to ammonia can cause some serious symptoms such as headaches, burns, and even permanent damage to the eyes and lungs. In order to understand the emission of ammonia from indoor concrete wall in civil building and assess the health risk of people living in these buildings, the experimental pieces of concrete wall were first prepared by concreting cement and urea-based antifreeze admixtures to simulate the indoor wall in civil building in this work. Then environmental chamber was adopted for studying the effect of temperature, relative humility and air exchange rate on emission of ammonia from experimental pieces of concrete wall. Also the field experiment was made at selected rooms in given civil buildings. Exposure and potential dose of adult and children exposed to indoor/outdoor ammonia in summer and in winter are calculated and evaluated by using Scenario Evaluation Approach. The results indicated that high air exchange rate leads to decreased ammonia concentration, and elevation of temperature causes increasing ammonia concentration and volatilizing rate in chamber. The complete emission of ammonia from the wall containing urea-based antifreeze admixtures needs more than 10 years in general. Ventilating or improving air exchange can play a significant role in reducing ammonia concentration in actual rooms in field experiments. Urea-based antifreeze admixtures in concrete wall can give rise to high exposure and potential dose, especially in summer. Generally, adults have a high potential dose than children, while children have personal average dose rate beyond adults in the same conditions.

Use of the chemiluminescent probe lucigenin to monitor the production of the superoxide anion radical in a recombinant Aspergillus niger (B1-D)

Direct detection of intracellular superoxide anion radical (O(2)(.-)) production is of critical importance for investigating the responses of filamentous fungi to oxidative stress in bioprocesses. The purpose of this study is to establish a reliable method to monitor the O(2)(.-) production within pellets of Aspergillus niger. Addition of pure oxygen and the redox cycling agent paraquat to fungal pellet suspensions resulted in a considerable increase in lucigenin-derived chemiluminescence (LDCL). In the presence of exogenous superoxide dismutase (SOD), the LDCL of a disrupted cell solution was inhibited. In contrast, with addition of diethyldithiocarbamate and sodium azide, respectively, the inhibitors of Cu, Zn-SOD and Mn-SOD, an increased LDCL was observed. Further, as a probe, lucigenin can be absorbed and accumulated in fungal pellet within a few minutes. Various pretreatments of the bioreactor sample for the measurement of LDCL, were also investigated in the present study, and the use of intact pellets was adopted here rather than disrupting cells because the latter treatment led to difficulties in LDCL measurement. These results show that lucigenin may be used as a convenient chemiluminescent probe to monitor intracellular production of O(2)(.-) in filamentous fungi, and thus to follow changes in the level of this stressor within fungi

Important ECG diagnosis-aiding indices of ventricular septal defect children with or without congestive heart failure

In this paper we perform a statistical study of the conventional RR intervals and two newly defined PR' and RT intervals of ECG data. A quadratic classification rule is applied to extract several important ECG diagnosis-aiding indices among normal children and children with ventricular septal defect (VSD) with or without congestive heart failure (CHF). The results show that certain statistics computed from PR', RR and RT intervals are important diagnosis-aiding indices. Best classification vectors are searched for pairwise classification. Two methods, minimum distance criterion and a two-stage classification procedure, are considered for three-way classification. Furthermore, logistic regression models based on transformations of these important diagnosis-aiding indices are proposed. The receiver operating characteristic curves of the proposed models show better performance than those of linear and quadratic logistic models. In order to proceed with this study, a computer algorithm to automatically detect the three intervals is developed and the related ECG data are collected and analysed. The algorithm is also enhanced with an outlier detection procedure for the automatic measurements of the PR' and RT intervals.

Boiler briquette coal versus raw coal: Part II--Energy, greenhouse gas, and air quality implications

The objective of this paper is to conduct an integrated analysis of the energy, greenhouse gas, and air quality impacts of a new type of boiler briquette coal (BB-coal) in contrast to those of the raw coal from which the BB-coal was formulated (R-coal). The analysis is based on the source emissions data and other relevant data collected in the present study and employs approaches including the construction of carbon, energy, and sulfur balances. The results show that replacing R-coal with BB-coal as the fuel for boilers such as the one tested would have multiple benefits, including a 37% increase in boiler thermal efficiency, a 25% reduction in fuel demand, a 26% reduction in CO2 emission, a 17% reduction in CO emission, a 63% reduction in SO2 emission, a 97% reduction in fly ash and fly ash carbon emission, a 22% reduction in PM2.5 mass emission, and a 30% reduction in total emission of five toxic hazardous air pollutant (HAP) metals contained in PM10. These benefits can be achieved with no changes in boiler hardware and with a relatively small amount of tradeoffs: a 30% increase in PM10 mass emission and a 9-16% increase in fuel cost.

Boiler briquette coal versus raw coal: Part I--Stack gas emissions

Stack gas emissions were characterized for a steam-generating boiler commonly used in China. The boiler was tested when fired with a newly formulated boiler briquette coal (BB-coal) and when fired with conventional raw coal (R-coal). The stack gas emissions were analyzed to determine emission rates and emission factors and to develop chemical source profiles. A dilution source sampling system was used to collect PM on both Teflon membrane filters and quartz fiber filters. The Teflon filters were analyzed gravimetrically for PM10 and PM2.5 mass concentrations and by X-ray fluorescence (XRF) for trace elements. The quartz fiber filters were analyzed for organic carbon (OC) and elemental carbon (EC) using a thermal/optical reflectance technique. Sulfur dioxide was measured using the standard wet chemistry method. Carbon monoxide was measured using an Orsat combustion analyzer. The emission rates of the R-coal combustion (in kg/hr), determined using the measured stack gas concentrations and the stack gas emission rates, were 0.74 for PM10, 0.38 for PM2.5, 20.7 for SO2, and 6.8 for CO, while those of the BB-coal combustion were 0.95 for PM10, 0.30 for PM2.5, 7.5 for SO2, and 5.3 for CO. The fuel-mass-based emission factors (in g/kg) of the R-coal, determined using the emission rates and the fuel burn rates, were 1.68 for PM10, 0.87 for PM2.5, 46.7 for SO2, and 15 for CO, while those of the BB-coal were 2.51 for PM10, 0.79 for PM2.5, 19.9 for SO2, and 14 for CO. The task-based emission factors (in g/ton steam generated) of the R-coal, determined using the fuel-mass-based emission factors and the coal/steam conversion factors, were 0.23 for PM10, 0.12 for PM2.5, 6.4 for SO2, and 2.0 for CO, while those of the BB-coal were 0.30 for PM10, 0.094 for PM2.5, 2.4 for SO2, and 1.7 for CO. PM10 and PM2.5 elemental compositions are also presented for both types of coal tested in the study.

Nanomechanics of individual carbon nanotubes from pyrolytically grown arrays

The bending modulus of individual carbon nanotubes from aligned arrays grown by pyrolysis was measured by in situ electromechanical resonance in transmission electron microscopy (TEM). The bending modulus of nanotubes with point defects was approximately 30 GPa and that of nanotubes with volume defect was 2-3 GPa. The time-decay constant of nanotube resonance in a vacuum of 10(-4) Torr was approximately 85 micros. A femtogram nanobalance was demonstrated based on nanotube resonance; it has the potential for measuring the mass of chain-structured large molecules. The in situ TEM provides a powerful approach towards nanomechanics of fiberlike nanomaterials with well-characterized defect structures.

[Upper airway occlusion sites of obstructive sleep apnea]

OBJECTIVE

To locate the obstruction sites in patients with obstructive sleep apnea syndrome (OSAS) during sleep by MRI imaging and dynamic fiberoptic pharyngoscopy.

METHODS

Fifteen OSAS patients confirmed by polysomnography (PSG) underwent ultrafast MR imaging during sleep. Their sequential midline sagittal and axial images were obtained and displayed in the cine mode. Then we examined the upper airway of the retropalate region (RP), retroglottal region (RG) and epiglottal region (EPG). We also did dynamic fiberoptic pharyngoscopy examination during sleep in 8 patients in another night.

RESULTS

Among the 15 patients, 3 had only RP region obstruction, 2 had only RG region obstruction, and the other 10 had both RP & RG airway obstruction. In the 8 cases monitored with both MRI and fiberoptic pharyngoscopy, the results obtained from the 2 methods were identical.

CONCLUSION

MRI and fiberoptic pharyngoscopy are useful in locating the pharyngeal airway obstruction sites of OSAS patients and would be helpful in selecting treatment measures.

[The upper airway MRI of obstructive sleep apnea patients]

OBJECTIVE

To investigate the mechanisms of obstructive sleep apnea syndrome(OSAS) through observing the upper airway caliber and its corresponding pharyngeal wall of OSAS patients by MRI.

METHODS

The upper airway(UA) of 18 OSAS patients were examined by MRI. The cross-sectional area of the UA and lateral parapharyngeal fat pad (LPFP) were calculated. The thickness of lateral and posterior pharyngeal wall (LW & PW) and other related indices were also measured. Nineteen nonsnoring age-matched normal subjects were selected as the control group.

RESULTS

1. The retropalatal (RP) and retroglossal (RG) region UA cross-sectional areas of OSAS patients were smaller than that of the control (P < 0.05). The epiglottal (EPC) region UA cross-sectional area was not significantly different between the 2 groups (P = 0.204). 2. The anterior-posterior/Lateral ratio(A-P/L) of UA in RP, RG, EPG regions was bigger in patients group than that of the control (P < 0.05). 3. The cross-sectional area of LPFP in patients group was larger than that of the control group (P = 1.76E-7). 4. The thickness of the PW in the RP, RG and EPG region was thicker in patients group than that of the control (P < 0.05). Although the thickness of the LW in the RP region was not statistically different between the 2 groups (P = 0.94), this index in RG and EPG region was larger in patients group than that of the control (P = < 0.05). 5. Sagittal MRI image showed that the length, thickness and cross-sectional area of the palate in patient group was larger than that of the control (P < 0.01).

CONCLUSIONS

The study suggests that the pathogenesis of OSAS is related to the following factors: UA caliber and its AP/L ratio, the thickness of LW and PW, the size of LPFP in RP region, and the size and length of the palate.

[Combined effects of lead and ethanol on rat sperms]

In order to study the combined effects of lead and ethanol on rat sperm, 54 male rats were divided into 9 groups randomly. One group was given distilled water as control, and the others (A-H) groups were given lead and ethanol at the concentrations of lead 11 mg/kgBW and lead 22 mg/kgBW, ethanol 0.9 g/kgBW, ethanol 1.8 g/kgBW, lead 11 mg/kgBW + ethanol 0.9 g/kgBW, lead 11 mg/kgBW + ethanol 1.8 g/kgBW, lead 22 mg/kgBW + ethanol 0.9 g/kgBW, lead 22 mg/kgBW + ethanol 1.8 g/kgBW in stomachs respectively for four weeks. The rats were sacrificed by the end of the fourth week. Epididymis were isolated and examined for sperm motility, counts and morphology. The results showed that the spermatozoa motility as well as spermatozoa count was lower; the spermatozoa morphological changed and blood lead level and ratio of epididymis to weight were higher in all combined experimental groups than those in groups with lead or ethanol alone. ANOVA analysis indicated that there were interaction between lead and ethanol on above indices (P < 0.05 P < 0.01). The multiple linear regression showed that there was linear correlation between blood lead and spermatozoa motility, spermatozoa morphological change. It is concluded that there were notable combined effects of lead and ethanol on semen quality in male rats.

Epidemiology of cervical and trochanteric fractures of the proximal femur in 1994 in Tangshan, China

The purpose of this study was to determine the incidence of cervical and trochanteric fractures of the proximal femur in 1994 in Tangshan City, China. There are many reports on hip fracture incidence in many countries, suggesting that there are many factors affecting hip fractures. We visited 15 hospitals with an orthopaedic department within Tangshan City, and reviewed the medical records and radiographs of all patients with hip fractures occurring between January 1 and December 31, 1994. The population of Tangshan in 1994 was determined to be 1,454,543 (746,015 males and 708,528 females). The population of those over 65 years of age was 88,490 (41,519 males and 46,971 females), representing 6.08% of the total population. This study detected 184 cervical and trochanteric fractures of the proximal femur in 1994 in Tangshan (127 men and 57 women). The overall incidence or rate of the combined number of cervical and trochanteric fractures was 25 fractures per 100,000 population per year for men and 12 for women. There were a total of 147 cervical fractures (80%) and 37 trochanteric fractures (20%). The incidence of the combined number of cervical and trochanteric fractures in patients over 70 years of age increased to 108 for men and 156 for women. The incidence of hip fractures increased with age in both sex groups, especially in women over 65. Severe trauma fractures happened more often in younger groups, and mainly occurred in men, which may be a result of the particular composition of the population in Tangshan, which is young and male dominated. In addition, because Tangshan is an industrial city, many of its citizens are involved in occupations requiring a high level of physical activity.