Ear piercing: A review on the legislative regulations and potential health hazards; its relevance to family physicians

Ear piercing is very popular. Legislation regulating the practice of ear piercing is lacking in Hong Kong. Complications arising from this normally low risk procedure do occur, especially with high ear piercing and improper techniques or instruments. This article reviews the existing legislations governing ear-piercing in different countries and the potential health hazards associated with ear-piercing. We hope to increase the awareness of the general public and primary care physicians to the potential serious medical problems that can result from such a minor procedure, which is performed for cosmetic reasons; and to prevent these complications from happening.published_or_final_versio

Game theoretical multi-agent modelling of coalition formation for multilateral trades

In recent years, electric utility industries worldwide have been undergoing deregulation to introduce competitiveness in the generation, transmission and distribution of electric power. The once centralised system planning and operation management must be remodelled to adapt to the new market structure. In particular, the trading mechanism needs to be totally revised as any party may now get involved in this free-market, subject to the unavoidable constraints such as generation volumes, physical transmission means and days-ahead scheduling. This paper presents a multi-agent model in conjunction with game theory to resolve the coalition formation for multilateral trades. The authors have implemented the model using the Java language and the JATLite/JAT0.3 agent development tools developed by Stanford University.published_or_final_versio

Breast reconstruction with transverse rectus abdominis musculocutaneous (TRAM) flap in young women with breast cancer

Since its introduction in 1982, the transverse rectus nbdominis musculocutaneous (TRAM) flop has become the standard for autogenous breast reconstruction. However, it has serious potential complications. In this article, the 10 TRAM flaps performed at Princess Margaret Hospital from December 1993 to September 1994 for young women with breast carcinoma were evaluated to assess the safety and complications of this technique. Majority of the patients were satisfied with the cosmetic outcome.published_or_final_versio

Studies in RF power communication, SAR, and temperature elevation in wireless implantable neural interfaces

Implantable neural interfaces are designed to provide a high spatial and temporal precision control signal implementing high degree of freedom real-time prosthetic systems. The development of a Radio Frequency (RF) wireless neural interface has the potential to expand the number of applications as well as extend the robustness and longevity compared to wired neural interfaces. However, it is well known that RF signal is absorbed by the body and can result in tissue heating. In this work, numerical studies with analytical validations are performed to provide an assessment of power, heating and specific absorption rate (SAR) associated with the wireless RF transmitting within the human head. The receiving antenna on the neural interface is designed with different geometries and modeled at a range of implanted depths within the brain in order to estimate the maximum receiving power without violating SAR and tissue temperature elevation safety regulations. Based on the size of the designed antenna, sets of frequencies between 1 GHz to 4 GHz have been investigated. As expected the simulations demonstrate that longer receiving antennas (dipole) and lower working frequencies result in greater power availability prior to violating SAR regulations. For a 15 mm dipole antenna operating at 1.24 GHz on the surface of the brain, 730 uW of power could be harvested at the Federal Communications Commission (FCC) SAR violation limit. At approximately 5 cm inside the head, this same antenna would receive 190 uW of power prior to violating SAR regulations. Finally, the 3-D bio-heat simulation results show that for all evaluated antennas and frequency combinations we reach FCC SAR limits well before 1 °C. It is clear that powering neural interfaces via RF is possible, but ultra-low power circuit designs combined with advanced simulation will be required to develop a functional antenna that meets all system requirements. © 2013 Zhao et al

Melatonin and 2[125I]iodomelatonin binding sites in the human colon

2[125I]Iodomelatonin binding sites were identified in the mucosa of the human colon from Chinese patients with carcinoma of the rectum or colon using biochemical receptor assay and autoradiography. Melatonin in the colonic mucosa/submucosa and muscle layers were quantitated by radioimmunoassay. The binding of 2[125I]iodomelatonin to the membrane preparations of the human colonic mucosa/submucosa was stable, saturable, reversible and of high affinity. Rosenthal analysis from saturation studies performed at 21°C yielded an equilibrium dissociation constant (Kd) of 61.7±4.48 pmol/L (n=3) and maximum number of binding sites (Bmax) of 1.65±0.51 fmol/mg protein (n=3). The linearity of the Rosenthal plots and unity of the Hill coefficient suggested that 2[125I]iodomelatonin was bound to a single class of binding sites. The radioligand binding was displaced by 2-iodomelatonin (Ki=0.02 nmol/L), melatonin (0.65 nmol/L), 6-chloromelatonin (Ki=5.33 nmol/L), 6-hydroxymelatonin (Ki=33.8 nmol/L) and N-acetylserotonin (Ki= 122 nmol/L). The characteristics of the binding sites were similar to those reported in the jejunum of duck, chicken and human but of higher affinity than those in the mouse colon. Autoradiography localizes the binding to the mucosa of the human colon. Radioimmunoassay revealed a melatonin concentration of 467±99 pg/g wet tissue of human colon (n=6). Our findings suggest that melatonin may influence the human colonie functions through interaction with its receptors in the mucosa.link_to_subscribed_fulltex

Use of preputial skin for the release of burn contractures in children

Contractures are frequent sequelae of burn injuries. Progressive worsening of contractures with limitation of joint movement is common in children. The results of release procedures in 10 male Chinese children using their own preputial skin obtained from circumcision were reviewed. This technique yields reliable results and is well accepted by the parents.link_to_subscribed_fulltex

Degrees of freedom in multiple-antenna channels: a signal space approach

Multiple-antenna systems that are limited by the area and geometry of antenna arrays, are considered. Given these physical constraints, the limit on the available number of spatial degrees of freedom is derived. The commonly used statistical multiple-input multiple-output (MIMO) model is inadequate. Antenna theory is applied to take into account the area and geometry constraints, and to define the spatial signal space so as to interpret experimental channel measurements in an array-independent but manageable description of the physical environment. Based on these modeling strategies, for a spherical array of effective aperture A in a physical environment of angular spread | Omega | in solid angle, the number of spatial degrees of freedom is shown to be A| Omega | for uni-polarized antennas and 2A| Omega | for tri-polarized antennas. Together with the 2WT degrees of freedom for a system of bandwidth W transmitting in an interval T, the total degrees of freedom of a multiple-antenna channel is therefore 4WTA| Omega |

Association of IgA nephropathy with T cell receptor constant alpha chain gene polymorptism

T-cell receptor (TCR) proteins recognize a complex of an antigen-derived peptide bound to the cell surface products of the major histocompatibility complex (MHC) that could be of importance in the immunopathogenesis of IgA nephropathy (IgAN). Previous studies found no difference on TCR constant β chain gene frequencies in IgAN compared with control. Yet no study on the TCR α gene in IgAN was reported. We studied the TCR Cα gene polymorphisms by restriction fragment length polymorphism (RFLP) in 53 patients with IgAN and in comparison with 67 healthy controls. The patients were also classified into different histopathological grading (I, II, and III with increasing histological severity) and renal functions. The extracted DNA were digested with Taq I enzymes and probed with a full-length TCR-α cDNA clone p1.2α probe. A 7-kb C-α Taq 1 fragment is found in 32 of 53 patients (60.3%) compared with 26 of 67 controls (38.8%) (P < 0.05). There was no association of any polymorphic fragment, including the 7-kb fragment, with either the histological grading or renal function. It is concluded that the TCR C-α gene is associated with IgAN but not with the prognosis of the disease