A feasibility study on active sound reduction across an acoustic plenum window by cancelling source clusters on internal periphery of the window cavity.

The possibility of applying active control to reduce sound transmission across a practical plenum window is examined experimentally in the present study using measured transfer functions of all related sound transmission paths. As a result of the limited space within the window, the error microphones are located at the indoor window opening while the secondary cancelling sources are mounted along the periphery of the window void. Results show that the cancelling sources near the outdoor window opening corners and within the overlapping region of the window play more useful roles in the control. Also, the highest sound reduction is around 6 dB with six error microphones positioned either at the central region or along the periphery of the indoor window opening. However, the results with the central error microphones suggest the possibility of adopting a dual control system to enhance the low frequency performance. Control systems with fewer error microphones result in lower sound reduction. Besides, it is found that four cancelling sources, located around the outdoor opening of the window, will be enough to achieve meaningful active sound transmission reduction between 100 and 1000 Hz. Involving more cancelling sources does not result in better performance despite the added complexity.

Fat necrosis in the breast: a multimodality imaging review of its natural course with different aetiologies.

Fat necrosis of the breast is a commonly encountered condition in daily practice. It is a benign pathology, but it can have variable manifestations and patterns that may sometimes mimic malignancy, depending on its stage of evolution and its underlying cause. This review demonstrates the wide spectrum of appearances of fat necrosis on mammography, digital breast tomosynthesis (DBT), ultrasound, magnetic resonance imaging (MRI), computed tomography (CT), and positron-emission tomography (PET). Sequential follow-up images are included in some cases to illustrate the temporal change of the findings. The typical location and distribution of fat necrosis from a comprehensive list of aetiologies are discussed. Improved knowledge of the multimodality imaging features of fat necrosis could enhance diagnostic accuracy and clinical management, thus avoiding unnecessary invasive investigations.

Novel wearable and contactless heart rate, respiratory rate, and oxygen saturation monitoring devices: a systematic review and meta-analysis.

We performed a systematic review and meta-analysis to identify, classify and evaluate the body of evidence on novel wearable and contactless devices that measure heart rate, respiratory rate and oxygen saturations in the clinical setting. We included any studies of hospital inpatients, including sleep study clinics. Eighty-four studies were included in the final review. There were 56 studies of wearable devices and 29 of contactless devices. One study assessed both types of device. A high risk of patient selection and rater bias was present in proportionally more studies assessing contactless devices compared with studies assessing wearable devices (p = 0.023 and p < 0.0001, respectively). There was high but equivalent likelihood of blinding bias between the two types of studies (p = 0.076). Wearable device studies were commercially available devices validated in acute clinical settings by clinical staff and had more real-time data analysis (p = 0.04). Contactless devices were more experimental, and data were analysed post-hoc. Pooled estimates of mean (95%CI) heart rate and respiratory rate bias in wearable devices were 1.25 (-0.31-2.82) beats.min-1 (pooled 95% limits of agreement -9.36-10.08) and 0.68 (0.05-1.32) breaths.min-1 (pooled 95% limits of agreement -5.65-6.85). The pooled estimate for mean (95%CI) heart rate and respiratory rate bias in contactless devices was 2.18 (3.31-7.66) beats.min-1 (pooled limits of agreement -6.71-10.88) and 0.30 (-0.26-0.87) breaths.min-1 (pooled 95% limits of agreement -3.94-4.29). Only two studies of wearable devices measured Sp O2 ; these reported mean measurement biases of 3.54% (limits of agreement -5.65-11.45%) and 2.9% (-7.4-1.7%). Heterogeneity was observed across studies, but absent when devices were grouped by measurement modality and reference standard. We conclude that, while studies of wearable devices were of slightly better quality than contactless devices, in general all studies of novel devices were of low quality, with small (< 100) patient datasets, typically not blinded and often using inappropriate statistical techniques. Both types of devices were statistically equivalent in accuracy and precision, but wearable devices demonstrated less measurement bias and more precision at extreme vital signs. The statistical variability in precision and accuracy between studies is partially explained by differences in reference standards.

Measurement of airborne particle exposure during simulated tracheal intubation using various proposed aerosol containment devices during the COVID-19 pandemic.

The COVID-19 pandemic has led to the production of novel devices intended to protect airway managers during the aerosol-generating procedure of tracheal intubation. Using an in-situ simulation model, we evaluated laryngoscopist exposure of airborne particles sized 0.3 - 5.0 microns using five aerosol containment devices (aerosol box; sealed box with and without suction; vertical drape; and horizontal drape) compared with no aerosol containment device. Nebulised saline was used as the aerosol-generating model for 300 s, at which point, the devices were removed to assess particle spread. Primary outcome was the quantity and size of airborne particles measured at the level of the laryngoscopist's head at 30, 60, 120 and 300 s, as well as 360 s (60 s after device removal). Airborne particles sizes of 0.3, 0.5, 1.0, 2.5 and 5.0 microns were quantified using an electronic airborne particle counter. Compared with no device use, the sealed intubation box with suction resulted in a decrease in 0.3, 0.5, 1.0 and 2.5 micron, but not 5.0 micron, particle exposure over all time-periods (p = 0.003 for all time periods). Compared with no device use, the aerosol box showed an increase in 1.0, 2.5 and 5.0 micron airborne particle exposure at 300 s (p = 0.002, 0.008, 0.002, respectively). Compared with no device use, neither horizontal nor vertical drapes showed any difference in any particle size exposure at any time. Finally, when the patient coughed, use of the aerosol box resulted in a marked increase in airborne particle exposure compared with other devices or no device use. In conclusion, novel devices intended to protect the laryngoscopist require objective testing to ensure they are fit for purpose and do not result in increased airborne particle exposure.

Dominance of Tensor Correlations in High-Momentum Nucleon Pairs Studied by (p,pd) Reaction.

The isospin character of p-n pairs at large relative momentum has been observed for the first time in the ^{16}O ground state. A strong population of the J,T=1,0 state and a very weak population of the J,T=0,1 state were observed in the neutron pickup domain of ^{16}O(p,pd) at 392 MeV. This strong isospin dependence at large momentum transfer is not reproduced by the distorted-wave impulse approximation calculations with known spectroscopic amplitudes. The results indicate the presence of high-momentum protons and neutrons induced by the tensor interactions in the ground state of ^{16}O.

Skin squames contribute to ammonia and volatile fatty acid production from bacteria colonizing in air-cooling units with odor complaints.

One of the most notable Indoor Air Quality problems is odor emission. This study investigated the potential contribution of skin squames to the production of ammonia (NH3 ) and volatile organic acids (VFAs) by 7 bacteria isolated from air-cooling (AC) units with complaints of urine and body odors. Our previous study showed that keratinolytic activity is higher in AC units with odor complaints than those without. In the offices where these units are located, the most likely source of keratins is from human skin squames. Most bacteria can produce NH3 and VFAs in the skin squame culture. Some correlations between the levels of NH3 , NH4+, VFAs, and keratinolytic activity were found. The odor production pathway with skin squames was proposed. Staphylococcus haemolyticus was abundant in the AC units with odor problems and had a high level of keratinolytic activity in addition to odor production. For long-term odor control, it is important to reduce the level of skin squames entering the AC units.

Pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma presented as cystic lung disease - a case report in Tuen Mun Hospital Hong Kong.

We report a rare case of pulmonary mucosa-associated lymphoid tissue lymphoma (MALToma) in a 52-year-old woman presented as cystic lung disease together with ground-glass lesion on computed tomography (CT) of the thorax incidentally found as part of workup for organ donation.

Extensive dissemination of CTX-M-producing Escherichia coli with multidrug resistance to 'critically important' antibiotics among food animals in Hong Kong, 2008-10.

OBJECTIVES: To assess the occurrence of faecal carriage of Escherichia coli with resistance to 'critically important' antibiotics in various animals. METHODS: Rectal or cloacal swabs were obtained weekly from cattle, pigs, chickens, cats, dogs and wild rodents over a 2 year period. Plain and antibiotic-containing medium was used for bacterial isolation. Selected isolates were characterized by molecular methods. RESULTS: In total, 2106 faecal specimens from 398 cats, 460 chickens, 368 dogs, 210 cattle, 214 pigs and 456 rodents were cultured. The faecal carriage rate of extended-spectrum ß-lactamase (ESBL)-producing E. coli was highest in pigs (63.6%, 136/214) and lowest in rodents (4.2%, 19/456). The faecal ESBL-producing E. coli carriage rate for food-producing animals (53.6%, 474/884) was significantly higher than that for cats/dogs (14.0%, 107/766; P<0.01) and wild rodents (4.2%, 19/456; P<0.01). ESBL-producing isolates from food animals often (33%-81%) had multidrug (≥4) resistance to amikacin, chloramphenicol, ciprofloxacin, co-trimoxazole, gentamicin, nalidixic acid, netilmicin, nitrofurantoin and tetracycline. Most (91.2%) of the ESBL-producing isolates had CTX-M-type enzymes. A total of 10 alleles (3, 13, 14, 15, 24, 27, 28, 55, 65 and 98) from two CTX-M families (M1 and M9) were found. PFGE showed that the CTX-M-producing isolates were genetically diverse. CONCLUSIONS: This study shows that food animals are a major reservoir of E. coli with multidrug resistance to many antibiotics that are ranked as critically important in human medicine.

Micromanipulation of adhesion of a Jurkat cell to a planar bilayer membrane containing lymphocyte function-associated antigen 3 molecules.

Cell adhesion plays a fundamental role in the organization of cells in differentiated organs, cell motility, and immune response. A novel micromanipulation method is employed to quantify the direct contribution of surface adhesion receptors to the physical strength of cell adhesion. In this technique, a cell is brought into contact with a glass-supported planar membrane reconstituted with a known concentration of a given type of adhesion molecules. After a period of incubation (5-10 min), the cell is detached from the planar bilayer by pulling away the pipette holding the cell in the direction perpendicular to the glass-supported planar bilayer. In particular, we investigated the adhesion between a Jurkat cell expressing CD2 and a glass-supported planar bilayer containing either the glycosyl-phosphatidylinositol (GPI) or the transmembrane (TM) isoform of the counter-receptor lymphocyte function-associated antigen 3 (LFA-3) at a concentration of 1,000 molecules/microns 2. In response to the pipette force the Jurkat cells that adhered to the planar bilayer containing the GPI isoform of LFA-3 underwent extensive elongation. When the contact radius was reduced by approximately 50%, the cell then detached quickly from its substrate. The aspiration pressure required to detach a Jurkat cell from its substrate was comparable to that required to detach a cytotoxic T cell from its target cell. Jurkat cells that had been separated from the substrate again adhered strongly to the planar bilayer when brought to proximity by micromanipulation. In experiments using the planar bilayer containing the TM isoform of LFA-3, Jurkat cells detached with little resistance to micromanipulation and without changing their round shape.

Influence of receptor lateral mobility on adhesion strengthening between membranes containing LFA-3 and CD2.

We have used an in vitro model system of glass-supported planar membranes to study the effects of lateral mobility of membrane-bound receptors on cell adhesion. Egg phosphatidylcholine (PC) bilayers were reconstituted with two anchorage isoforms of the adhesion molecule lymphocyte function-associated antigen 3 (LFA-3). The diffusion coefficient of glycosyl phosphatidylinositol (GPI)-anchored LFA-3 approached that of phospholipids in the bilayers, whereas the transmembrane (TM)-anchored isoform of LFA-3 was immobile. Both static and laminar flow assays were used to quantify the strength of adherence to the lipid bilayers of the T lymphoma cell line Jurkat that expresses the counter-receptor CD2. Cell adhesion was dependent on LFA-3 density and was more efficient on membranes containing the GPI isoform than the TM isoform. Kinetic measurements demonstrated an influence of contact time on the strength of adhesion to the GPI isoform at lower site densities (25-50 sites/microns2), showing that the mobility of LFA-3 is important in adhesion strengthening. At higher site densities (1,500 sites/microns2) and longer contact times (20 min), Jurkat cell binding to the TM and GPI isoforms of LFA-3 showed equivalent adhesion strengths, although adhesion strength of the GPI isoform developed twofold more rapidly than the TM isoform. Reduction of CD2 mobility on Jurkat cells at 5 degrees C greatly decreased the rate of adhesion strengthening with the TM isoform of LFA-3, resulting in a 30-fold difference between the two LFA-3 isoforms. Our results demonstrate that the ability of a membrane receptor and its membrane-bound counter-receptor to diffuse laterally enhances cell adhesion both by allowing accumulation of ligands in the cell contact area and by increasing the rate of receptor-ligand bond formation.

Visualization of CD2 interaction with LFA-3 and determination of the two-dimensional dissociation constant for adhesion receptors in a contact area.

Many adhesion receptors have high three-dimensional dissociation constants (Kd) for counter-receptors compared to the KdS of receptors for soluble extracellular ligands such as cytokines and hormones. Interaction of the T lymphocyte adhesion receptor CD2 with its counter-receptor, LFA-3, has a high solution-phase Kd (16 microM at 37 degrees C), yet the CD2/LFA-3 interaction serves as an effective adhesion mechanism. We have studied the interaction of CD2 with LFA-3 in the contact area between Jurkat T lymphoblasts and planar phospholipid bilayers containing purified, fluorescently labeled LFA-3. Redistribution and lateral mobility of LFA-3 were measured in contact areas as functions of the initial LFA-3 surface density and of time after contact of the cells with the bilayers. LFA-3 accumulated at sites of contact with a half-time of approximately 15 min, consistent with the previously determined kinetics of adhesion strengthening. The two-dimensional Kd for the CD2/LFA-3 interaction was 21 molecules/microns 2, which is lower than the surface densities of CD2 on T cells and LFA-3 on most target or stimulator cells. Thus, formation of CD2/LFA-3 complexes should be highly favored in physiological interactions. Comparison of the two-dimensional (membrane-bound) and three-dimensional (solution-phase) KdS suggest that cell-cell contact favors CD2/LFA-3 interaction to a greater extent than that predicted by the three-dimensional Kd and the intermembrane distance at the site of contact. LFA-3 molecules in the contact site were capable of lateral diffusion in the plane of the phospholipid bilayer and did not appear to be irreversibly trapped in the contact area, consistent with a rapid off-rate. These data provide insights into the function of low affinity interactions in adhesion.

Psychometric properties of the Chinese (Cantonese) Tinnitus Handicap Inventory.

OBJECTIVES: To establish the reliability and validity of the Chinese (Cantonese) version of the Tinnitus Handicap Inventory to measure the self-perceived handicapping effect and severity of the condition in patients with chronic tinnitus. DESIGN: Cross-sectional psychometric validation study. SETTING: Audiology clinics in a hospital setting. PARTICIPANTS: Subjects were 114 adult Chinese who attended the audiology clinics with a complaint of tinnitus. MAIN OUTCOME MEASURES: Test-retest and internal consistency reliability; construct validity. RESULTS: The Chinese version of the Tinnitus Handicap Inventory and its subscales showed good internal consistency reliabilities (alpha = 0.72-0.94) that are comparable to those of the original version. High correlations were observed between the Tinnitus Handicap Inventory and psychological distress, tinnitus-related problem ratings and severity ratings. Factor analysis showed that the Chinese version of the Tinnitus Handicap Inventory has a unifactorial structure. A high degree of test-retest reliability was observed (intraclass correlation coefficient = 0.88). CONCLUSIONS: The results suggest that the Chinese (Cantonese) version of the Tinnitus Handicap Inventory is a reliable and valid measure of general tinnitus-related distress that can be used in clinical settings to quantify the impact of tinnitus on daily life.

Freeing Chinese Abused Women From Stereotype: A Pretest-Posttest Comparison Study on Group Intervention in Refuge Centers.

OBJECTIVE: The efficacy of heal-change group (HCG) intervention-brief trauma-recovery group intervention applying a gender-specific cognitive behavioral approach-for Chinese-abused women in refuge centers was examined in a pretest-posttest comparison study. METHODS: A total of 100 women at three refuge centers in Hong Kong participated. Among them, 50 women from two centers joined the HCG and 50 women from the remaining center participated in a comparison mutual support group. Participants and interviewers were blinded to the group assignment. Both groups were six sessions long. Linear regression analyses were performed using the intention-to-treat framework. RESULTS: Significant improvements in PTSD symptoms (overall mean change of -1.6, p < .001; subdomain scores; p < .001 to < .01) and depressive symptoms (BDI-II mean change; p < .01) were recorded in the intervention group. CONCLUSION: The results suggest HCG is beneficial to Chinese-abused women. Further research is needed to determine the intervention's effectiveness in improving longer-term outcomes in these women.

Evidence for prevalent Z = 6 magic number in neutron-rich carbon isotopes.

The nuclear shell structure, which originates in the nearly independent motion of nucleons in an average potential, provides an important guide for our understanding of nuclear structure and the underlying nuclear forces. Its most remarkable fingerprint is the existence of the so-called magic numbers of protons and neutrons associated with extra stability. Although the introduction of a phenomenological spin-orbit (SO) coupling force in 1949 helped in explaining the magic numbers, its origins are still open questions. Here, we present experimental evidence for the smallest SO-originated magic number (subshell closure) at the proton number six in 13-20C obtained from systematic analysis of point-proton distribution radii, electromagnetic transition rates and atomic masses of light nuclei. Performing ab initio calculations on 14,15C, we show that the observed proton distribution radii and subshell closure can be explained by the state-of-the-art nuclear theory with chiral nucleon-nucleon and three-nucleon forces, which are rooted in the quantum chromodynamics.

Effect of lengthening lymphocyte function-associated antigen 3 on adhesion to CD2.

The effect of lengthening the distance in an adhesion molecule between the receptor binding site and the membrane anchor was studied by inserting four Ig-like domains into the two Ig domain lymphocyte function-associated antigen 3 (LFA-3) molecule. The extended molecule expressed in Chinese hamster ovary (CHO) cells bound to CD2 on T lymphocytes 4- to 20-fold more efficiently than the wild-type molecule at 4 degrees C. Treatment of the CHO clones with neuraminidase to remove sialic acid, or with deoxymannojirimycin to reduce the bulk of N-linked glycosylation, showed that adhesion to both the wild-type and the chimeric LFA-3 molecules was under the influence of cell-cell repulsive forces to a similar extent and that these treatments had less effect than lengthening LFA-3. At higher temperatures, such as 22 and 37 degrees C, the efficiency of binding to the wild-type LFA-3 increased to levels comparable with binding to extended LFA-3. Our results suggest that more distal locations of the adhesive binding site from the cell membrane anchor increase the efficiency of cell-cell adhesion by enhancing the frequency of receptor encounter with ligand and that more proximal locations of the adhesive binding site can provide efficient cell-cell adhesion at physiological temperatures.

Add-on tests for improving risk-stratification in emergency department patients with chest pain who are at low to moderate risk of 30-day major adverse cardiac events.

BACKGROUND: Chest pain patients commonly present to emergency departments (ED), and require either hospital admission and/or lengthy diagnostic protocols to rule-out myocardial infarction. We aimed to identify the best combination of add-on tests to high-sensitivity cardiac troponin (hs-cTnT) for predicting 30-day major adverse cardiac events (MACE) in adult chest pain patients presenting to an ED with suspected acute coronary syndrome. METHODS: This prospective observational study was conducted in the ED of a tertiary university hospital in Hong Kong, recruiting adult patients with chest pain of less than 24h duration, suspected with acute coronary syndrome (ACS), and had no history of coronary artery bypass grafting or stent insertion. Patients underwent triage assessment, electrocardiography, blood sampling for laboratory hs-cTnT, and Thrombolysis in Myocardial Infarction (TIMI) and HEART score assessment. The primary outcome was the number of patients with 30-day MACE. RESULTS: 602 consecutive patients were recruited and completed 30-day follow-up. A 30-day MACE occurred in 42 (7.0%) patients. Out of 12 possible models for stratifying patients at risk of 30-day MACE within 2h of ED arrival, a combination of electrocardiography (ECG) and one-time hs-cTnT (model 5) provided the simplest and most accurate model. A risk score of 0 to 5 was derived from raw coefficients of model 5. The risk score provided excellent calibration (P=0.91) and discrimination (AUC 0.87, 95% CI: 0.82 to 0.93). CONCLUSION: Appropriate early risk-stratification of patients with chest pain and possible ACS using a combination of ECG and one-time hs-cTnT may improve efficiency of care.

Coengagement of CD2 with LFA-1 or VLA-4 by bispecific ligand fusion proteins primes T cells to respond more effectively to T cell receptor-dependent signals.

To examine the effects of ligand engagement and accessory molecule juxtaposition on T cell receptor (TCR) signaling, we prepared LFA-3/ICAM-1 Rg and LFA-3/VCAM-1 Rg bispecific immunoglobulin fusion proteins (Rg, recombinant globulin). These novel fusion proteins allowed us to examine the effects of ligand driven co-engagement of T cell proteins CD2 and LFA-1 or CD2 and VLA-4 on TCR-dependent mobilization of intracellular Ca2+. We observed that preincubation of resting T cells with LFA-3/ICAM-1 Rg or LFA-3/VCAM-1 Rg fusion proteins resulted in significantly enhanced mobilization of intracellular Ca2+ following TCR-accessory molecule cross-linking relative to T cells preincubated with each of the monospecific Rgs alone or with combinations of the monospecific Rg fusion proteins. In addition, such coengagement stimulated TCR-dependent activation and tyrosine phosphorylation of phospholipase C gamma 1 (PLC gamma 1). These results suggest that when T cells interact with antigen presenting cells the engagement of multiple cell adhesion molecules such as CD2, LFA-1, and VLA-4 primes the T cell to respond more effectively to signals delivered through the TCR.

Layer by Layer Ex-Situ Deposited Cobalt-Manganese Oxide as Composite Electrode Material for Electrochemical Capacitor.

The composite metal oxide electrode films were fabricated using ex situ electrodeposition method with further heating treatment at 300°C. The obtained composite metal oxide film had a spherical structure with mass loading from 0.13 to 0.21 mg cm(-2). The structure and elements of the composite was investigated using X-ray diffraction (XRD) and energy dispersive X-ray (EDX). The electrochemical performance of different composite metal oxides was studied by cyclic voltammetry (CV) and galvanostatic charge-discharge (CD). As an active electrode material for a supercapacitor, the Co-Mn composite electrode exhibits a specific capacitance of 285 Fg(-1) at current density of 1.85 Ag(-1) in 0.5 M Na2SO4 electrolyte. The best composite electrode, Co-Mn electrode was then further studied in various electrolytes (i.e., 0.5 M KOH and 0.5 M KOH/0.04 M K3Fe(CN) 6 electrolytes). The pseudocapacitive nature of the material of Co-Mn lead to a high specific capacitance of 2.2 x 10(3) Fg(-1) and an energy density of 309 Whkg(-1) in a 0.5 M KOH/0.04 M K3Fe(CN) 6 electrolyte at a current density of 10 Ag(-1). The specific capacitance retention obtained 67% of its initial value after 750 cycles. The results indicate that the ex situ deposited composite metal oxide nanoparticles have promising potential in future practical applications.