Facile bioactive transformation of magnesium alloy surfaces for surgical implant applications.

The market for orthopedic implant alloys has seen significant growth in recent years, and efforts to reduce the carbon footprint of medical treatment (i.e., green medicine) have prompted extensive research on biodegradable magnesium-based alloys. Magnesium alloys provide the mechanical strength and biocompatibility required of medical implants; however, they are highly prone to corrosion. In this study, Mg-9Li alloy was immersed in cell culture medium to simulate degradation in the human body, while monitoring the corresponding effects of the reaction products on cells. Variations in pH revealed the generation of hydroxyl groups, which led to cell death. At day-5 of the reaction, a coating of MgCO3 (H2O)3, HA, and α -TCP appeared on sample surfaces. The coating presented three-dimensional surface structures (at nanometer to submicron scales), anti-corrosion effects, and an altered surface micro-environment conducive to the adhesion of osteoblasts. This analysis based on bio-simulation immersion has important implications for the clinical use of Mg alloys to secure regenerated periodontal tissue.

Photogating WS2 Photodetectors Using Embedded WSe2 Charge Puddles.

Performance of 2D photodetectors is often predominated by charge traps that offer an effective photogating effect. The device features an ultrahigh gain and responsivity, but at the cost of a retarded temporal response due to the nature of long-lived trap states. In this work, we devise a gain mechanism that originates from massive charge puddles formed in the type-II 2D lateral heterostructures. This concept is demonstrated using graphene-contacted WS2 photodetectors embedded with WSe2 nanodots. Upon light illumination, photoexcited carriers are separated by the built-in field at the WSe2/WS2 heterojunctions (HJs), with holes trapped in the WSe2 nanodots. The resulting WSe2 hole puddles provide a photoconductive gain, as electrons are recirculating during the lifetime of holes that remain trapped in the puddles. The WSe2/WS2 HJ photodetectors exhibit a responsivity of 3 × 102 A/W with a gain of 7 × 102 electrons per photon. Meanwhile, the zero-gate response time is reduced by 5 orders of magnitude as compared to the prior reports for the graphene-contacted pristine WS2 monolayer and WS2/MoS2 heterobilayer photodetectors due to the ultrafast intralayer excitonic dynamics in the WSe2/WS2 HJs.

Characterization of Shock-Sensitive Deposits from the Hydrolysis of Hexachlorodisilane.

In this work, the shock sensitivity of hexachlorodisilane (HCDS) hydrolysis products was studied. The hydrolysis conditions included vapor and liquid HCDS hydrolysis in moist air. Shock sensitivity was determined by using a Fall hammer apparatus. Extensive infrared studies were done for the hydrolysis products. It was found that the Si-Si bond in HCDS during hydrolysis is preserved and can be cleaved by shock, leading to intramolecular oxidation of the neighboring silanol (Si-OH) groups to form a networked Si-O-Si structure and hydrogen gas. The limiting impact energy for shock sensitivity was also found proportional to the oxygen/silicon ratio in the deposit. Finally, recommendations are given for controlling the shock sensitivity of the hydrolyzed deposit.

Clinical and laboratory analysis of influenza B infection in children in Taichung, Taiwan during the 2006-2007 flu season.

BACKGROUND: An epidemic of influenza B/Malaysia/2506/2004 was reported in Taiwan during the 2006-2007 flu season. We investigated the flu vaccination history and clinical and Laboratory characteristics of children with influenza B infection. METHODS: We enrolled children younger than 18 years old who visited one of two hospitals between November 2006 and February 2007 with influenza-like illnesses. Throat swabs were taken on their first visit and cultured for viruses. Complete and differential blood counts and blood biochemical parameters were analyzed in some children. RESULTS: Influenza virus was cultured from 51.0% of patients (101/198), 87 (86.1%) of who were infected with influenza virus type B. The remaining 14 (13.9%) were infected with influenza virus type AH3. The 87 children (median age 7.8 years) with culture-proven influenza B virus infection were enrolled. Nine parents reported that enrolled children had been vaccinated against influenza. Leukopenia was found in 56.1% (32/57) of patients, leukocytosis in 3.5% (2/57), and thrombocytopenia in 1.8% (1/57). Thirteen of 23 patients (56%) tested for creatine kinase (CK) had elevated levels ( >160 U/L), and 11 of 23 (47.8%) had myalgia associated with raised CK (p < 0.05). Twenty-six children developed complications, including one case of pneumonia with acute respiratory distress syndrome and one case of flu-associated encephalitis. CONCLUSION: Most children who contracted influenza B infection had not been vaccinated. Almost half the children had leukopenia, and some had leukocytosis, but thrombocytopenia was rare. There was a significant association between raised CK levels and myalgia in influenza B infection.

Current status of Enterobius vermicularis infection in primary schoolchildren in Miaoli County and Taichung County, Taiwan.

BACKGROUND AND PURPOSE: No epidemiological survey of the prevalence of Enterobius vermicularis infection in Miaoli County and Taichung County has been conducted. This epidemiological survey was performed to describe the profile of E. vermicularis infection in schoolchildren in Miaoli County and Taichung County. METHODS: The first part of this study was conducted between November 2005 and February 2006 in Miaoli County. 44,071 primary schoolchildren from 18 districts were examined by 2 consecutive-day adhesive cellophane perianal swabs to estimate the infection rate. The second part was performed between October 2006 and January 2007 in Taichung County. 24,382 primary schoolchildren from 14 districts were examined. RESULTS: In Miaoli County, the infection rate was 2.39% (1054/44,071). The infection rate was highest in the Taian (6.69%; 20/299), Shytarn (4.49%; 11/245), and Dahu townships (3.6%; 40/1111). In Taichung County, the infection rate was 2.95% (720/24,382). The infection rate was highest in the Da-an (5.46%; 26/476) and Heping townships (4.48%; 9/201). The infection rate for a family with > or =3 children was significantly higher than that for a family with < or =2 children (p = 0.007). The frequency of washing linen and cleaning bedclothes significantly affected the infection rate of enterobiasis (p < 0.01). The efficacy rate for mebendazole was 96%, with no difference between 1 and 2 doses. CONCLUSIONS: The number of children per family and the frequency of washing linen and cleaning bedclothes were the most important factors for transmission of pinworm infection among the groups surveyed.